Browse Topic: Hydrogen fuel

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Hydrogen Fuel Quality for Fuel Cell VehiclesJ2719_202605 (Current)5/8/2026
This standard provides background information and a hydrogen fuel quality standard for commercial proton exchange membrane (PEM) fuel cell vehicles. This report also provides background information on how this standard was developed by the Hydrogen Quality Task Force (HQTF) of the Interface Working Group (IWG) of the SAE Fuel Cell Standards Committee.
Fuel Cell Standards Committee
Fuel Cell Vehicle TerminologyJ2574_202605 (Current)5/8/2026
This SAE Information Report contains definitions for hydrogen fuel cell powered vehicle terminology. It is intended that this document be a resource for those writing other hydrogen fuel cell vehicle documents, specifically, Standards or Recommended Practices.
Fuel Cell Standards Committee
Hydrogen Fuel Quality for Fuel Cell VehiclesJ2719_202510 (Current)10/15/2025
This standard provides background information and a hydrogen fuel quality standard for commercial proton exchange membrane (PEM) fuel cell vehicles. This report also provides background information on how this standard was developed by the Hydrogen Quality Task Force (HQTF) of the Interface Working Group (IWG) of the SAE Fuel Cell Standards Committee.
Fuel Cell Standards Committee
Fueling Protocols for Light Duty Gaseous Hydrogen Surface VehiclesJ2601_202005 (Current)5/29/2020
SAE J2601 establishes the protocol and process limits for hydrogen fueling of vehicles with total volume capacities greater than or equal to 49.7 L. These process limits (including the fuel delivery temperature, the maximum fuel flow rate, the rate of pressure increase, and the ending pressure) are affected by factors such as ambient temperature, fuel delivery temperature, and initial pressure in the vehicle’s compressed hydrogen storage system. SAE J2601 establishes standard fueling protocols based on either a look-up table approach utilizing a fixed pressure ramp rate, or a formula-based approach utilizing a dynamic pressure ramp rate continuously calculated throughout the fill. Both protocols allow for fueling with communications or without communications. The table-based protocol provides a fixed end-of-fill pressure target, whereas the formula-based protocol calculates the end-of-fill pressure target continuously. For fueling with communications, this standard is to be used in conjunction with SAE J2799. An important factor in the performance of hydrogen fueling is the station’s dispensing equipment cooling capability and the resultant fuel delivery temperature. There are three fuel delivery temperature categories denoted by a “T” rating: T40, T30, and T20, where T40 is the coldest. Under reference conditions, SAE J2601 has a performance target of a fueling time of 3 minutes and a state of charge (SOC) of 95 to 100% (with communications), which can be achieved with a T40-rated dispenser. However, with higher fuel delivery temperature dispenser ratings (T30 or T20) and/or at high ambient temperatures, fueling times may be longer. Table 1 depicts the scope of SAE J2601 and potential work items for future revisions within this or other documents of the SAE J2601 series. SAE J2601 includes protocols which are applicable for two pressure classes (35 MPa and 70 MPa), three fuel delivery temperatures categories (-40 °C, -30 °C, -20 °C) and compressed hydrogen storage system sizes (total volume classification) from 49.7 to 248.6 L (35 MPa ➔ H35, and 70 MPa ➔ H70), and from 248.6 L and above (H70 only). Future versions of SAE J2601 work may incorporate warmer fuel delivery temperatures (-10 °C and ambient) and smaller total volume capacities for motorcycles and other applications. The fueling protocols herein were developed based on a set of key assumptions described in Section 7 and Appendix A. These assumptions should be carefully considered in the development and implementation of an on-board compressed hydrogen storage system. In particular, hydrogen storage systems with properties which do not fall within the parameters in Table A3 should be further evaluated to confirm compatibility with the protocols herein.
Fuel Cell Standards Committee
Bearing Fault Diagnosis of the Gearbox Using Blind Source Separation2020-01-04364/14/2020
Gearbox fault diagnosis is one of the core research areas in the field of rotating machinery condition monitoring. The signal processing-based bearing fault diagnosis in the gearbox is considered as challenging as the vibration signals collected from acceleration transducers are, in general, a mixture of signals originating from an unknown number of sources, i.e. an underdetermined blind source separation (UBSS) problem. In this study, an effective UBSS-based algorithm solution, that combines empirical mode decomposition (EMD) and kernel independent component analysis (KICA) method, is proposed to address the technical challenge. Firstly, the nonlinear mixture signals are decomposed into a set of intrinsic mode function components (IMFs) by the EMD method, which can be combined with the original observed signals to reconstruct new observed signals. Thus, the original problem can be effectively transformed into over-determined BSS problem. Then, the whitening process is carried out to convert the over-determined BSS into determined BSS, which can be solved by the KICA method. Finally, the ant lion optimization (ALO) is adopted to further enhance the performance of the EMD-KICA method. The proposed solution is assessed through simulation experiments for non-linearly mixed bearing vibration signals, and the numerical result demonstrates the effectiveness of the proposed algorithmic solution.
Zhong, Hong, Liu, Jingxing, Wang, Liangmo, Ding, Yang, Qian, Yahui
Development of Dual Fuel Engine Fueled with Used Cooking Oil Biodiesel and Ethanol-an Experimental Study on Performance and Combustion Characteristics2020-01-08034/14/2020
This paper investigates the performance and combustion characteristics of a compression ignition engine (CI engine) fueled with Used Cooking Oil Biodiesel (UCOB) and ethanol in dual fuel mode. In this study, UCOB was injected as the main fuel through a conventional mechanical fuel injection system. Various mass flow rates of ethanol were inducted as primary fuel through the engine intake manifold using a separate fuel injection system. Mass flow rates of ethanol were metered by an electronic control circuit. The engine test was conducted under different load conditions from no load to full load in a fully instrumented direct injection, water-cooled compression ignition engine. The results indicated that the dual fuel engine produced higher brake thermal efficiency, cylinder pressure, heat release rate with lower specific fuel consumption at a higher load condition. However, it was found that combustion characteristics improved marginally at the lower load conditions.
Velmurugan, Ramanathan, Mayakrishnan, Jaikumar, Palanimuthu, Vijayabalan, Nandagopal, Sasikumar, Elumalai, Sangeethkumar, Anaimuthu, Shridhar, Busireddy, Vamshidhar
Fuel Reforming and Catalyst Deactivation Investigated in Real Exhaust Environment2019-01-03154/2/2019
Increased in-cylinder hydrogen levels have been shown to improve burn durations, combustion stability, HC emissions and knock resistance which can directly translate into enhanced engine efficiency. External fuel reformation can also be used to increase the hydrogen yield. During the High-Efficiency, Dilute Gasoline Engine (HEDGE) consortium at Southwest Research Institute (SwRI), the potential of increased hydrogen production in a dedicated-exhaust gas recirculation (D-EGR) engine was evaluated exploiting the water gas shift (WGS) and steam reformation (SR) reactions. It was found that neither approach could produce sustained hydrogen enrichment in a real exhaust environment, even while utilizing a lean-rich switching regeneration strategy. Platinum group metal (PGM) and Ni WGS catalysts were tested with a focus on hydrogen production and catalyst durability. Although 4% additional hydrogen was initially produced in the EGR stream, leading to improvements in the coefficient of variation (CoV) and brake specific fuel consumption (BSFC), catalyst activity decreased within a few hours regardless of the regeneration strategy employed. With an SR catalyst, a small amount of hydrogen was produced in the EGR stream via the WGS reaction but not the SR reaction. Similar to the WGS catalyst testing, the SR catalyst deactivated quickly due to coking. While neither of these approaches displayed acceptable long-term performance, the exhaust environment still poses a significant opportunity for the production of hydrogen rich reformate to deliver improvement in engine efficiency.
Bartley, Gordon, Gukelberger, Raphael, Henderson, Robert, Henry, Cary
Passive Metal Hydride Module Concept for Enhanced Low-Temperature Catalyst Performance2018-01-50015/4/2018
A technology concept applicable to stoichiometric and lean burn engine operation-a metal hydride (MHx) module for the generation of H2 via reaction with gaseous H2O-was evaluated for the introduction of low levels of H2 (ca. 500 ppmv) into internal combustion engine exhaust for the enhancement of catalyst performance at low temperatures, such as during cold-start. Projected MHx module packaging volume, replacement frequency, and costs over the lifetime of a light duty vehicle are excessive, and considered prohibitive to technology viability.
Bradford, Michael C.
Mechanisms of Enhanced Reactivity with Ozone Addition for Advanced Compression Ignition2018-01-12494/3/2018
Mechanisms responsible for enhanced charge reactivity with intake added ozone (O3) were explored in a single-cylinder, optically accessible, research engine configured for low-load advanced compression ignition (ACI) experiments. The influence of O3 concentration (0-40 ppm) on engine performance metrics was evaluated as a function of intake temperature and start of injection for the engine fueled by iso-octane, 1-hexene, or a 5-component gasoline surrogate. For the engine fueled by either the gasoline surrogate or 1-hexene, 25 ppm of added O3 reduced the intake temperature required for stable combustion by 65 and 80°C, respectively. An ultraviolet (UV) light absorption diagnostic was also used to measure crank angle (CA) resolved in-cylinder O3 concentrations for select motored and fired operating conditions. The O3 measurements were compared to results from complementary 0D chemical kinetic simulations that utilized detailed chemistry mechanisms augmented with O3 oxidation chemistry. From the measurements, rapid thermally induced O3 decomposition was observed during the compression stroke shortly before top dead center (TDC). Ozone decomposition advanced when the charge temperature was increased, oxygen concentration was reduced, or fuel was added. While the model well captures the experimental trends, for unfueled conditions the temporal prediction of O3 decomposition is generally too far retarded. The modeling further indicates the O3 decomposition leads to a burst of highly reactive atomic oxygen (O). For fueled conditions, the O rapidly abstracts fuel hydrogen to form hydroxyl (OH), which then leads to the substantial formation of hydroperoxyl (HO2) and hydrogen peroxide (H2O2). Strong UV light absorbance shortly after O3 decomposition confirms the presence of these species in the experiments. The in situ measurements are expected to aid kinetic model development of O3 decomposition processes and the associated influence of formed radicals on autoignition kinetics.
Ekoto, Isaac, Foucher, Fabrice
Reformed Fuel Substitution for Transient Peak Soot Reduction2018-01-02674/3/2018
Advancements in catalytic reforming have demonstrated the ability to generate syngas (a mixture of CO and hydrogen) from a single hydrocarbon stream. This syngas mixture can then be used to replace diesel fuel and enable dual-fuel combustion strategies. The role of port-fuel injected syngas, comprised of equal parts hydrogen and carbon monoxide by volume was investigated experimentally for soot reduction benefits under a transient load change at constant speed. The syngas used for the experiments was presumed to be formed via a partial oxidation on-board fuel reforming process and delivered through gaseous injectors using a custom gas rail supplied with bottle gas, mounted in the swirl runner of the intake manifold. Time-based ramping of the direct-injected fuel with constant syngas fuel mass delivery from 2 to 8 bar brake mean effective pressure was performed on a multi-cylinder, turbocharged, light-duty engine to determine the effects of syngas on transient soot emissions. A Cambustion fNOx400 high-speed emissions analyzer and an AVL 439 opacimeter were used to quantify emissions under the load change to provide sub-cycle and cycle resolved resolution, respectively. Results show substantial soot reduction benefits with modest levels of syngas without significant increases in NOx emissions under the chosen conditions.
Dal Forno Chuahy, Flavio, Olk, Jamen, Kokjohn, Sage
System and Second Law Analysis of the Effects of Reformed Fuel Composition in “Single” Fuel RCCI Combustion2018-01-02644/3/2018
Dual-fuel reactivity controlled compression ignition (RCCI) combustion is a promising method to achieve high efficiency with near-zero NOx and soot emissions; however, the requirement to carry two fuels on board limits practical application. Advancements in catalytic reforming have demonstrated the ability to generate syngas (a mixture of CO and hydrogen) from a single hydrocarbon stream. This syngas mixture can then be used as the low reactivity fuel stream to enable single fuel RCCI combustion. The present effort uses a combination of engine experiments and system level modeling to investigate reformed fuel RCCI combustion. The impact of reformer composition is investigated by varying the syngas composition from 10% H2 to approximately 80% H2. The results of the investigation show that reformed fuel RCCI combustion is possible over a wide range of H2/CO ratios. A system level and second law analysis are performed on the highest efficiency operating points, and comparisons are made between partial oxidation reforming, steam reforming, and conventional diesel. The results show that endothermic reforming (steam reforming) can achieve comparable system level efficiency to conventional diesel operation by recovering exhaust energy at similar system-out NOx emissions and near-zero soot emissions. An autoignition integral approach combined with reformer equilibrium modeling shows that in order to achieve higher system level efficiencies, lower H/C ratios of the parent fuel are necessary. Typical H/C ratio ranges for diesel fuels limit the range of operation of the engine to high hydrogen fractions, limiting the system level efficiency due to high heat transfer rates associated with these conditions.
Dal Forno Chuahy, Flavio, Kokjohn, Sage
Cryogenic and Non-Cryogenic Liquid Level InstrumentTBMG-281851/1/2018
NASA’s Marshall Space Flight Center has developed a unique prototype for measuring the liquid level in a tank, employing a novel process. The technology can operate in a wide range of environments, including high and low temperatures and pressures, and is simpler and less expensive than other optical sensing techniques. The instrument also provides far greater accuracy and faster results in cryogenic conditions than typical cryogenic liquid metering methods. It is ideal for cryogenic and non-cryogenic ground tank metering applications, and zero-gravity systems that include stratification or settling techniques.
Experimental and Kinetic Analyses of Thermochemical Fuel Reforming (TFR) with Alcohol Enrichment in Plug Flow Reactor: a Verification of In-Cylinder TFR2017-01-227810/8/2017
In-cylinder thermochemical fuel reforming (TFR) in spark ignition natural gas engine was developed to reveal that thermochemical fuel reforming could increase H2 and CO concentration in reformed gas, leading to an increase of thermal efficiency and engine performance. Moreover, ethanol enrichment has been proved to have great potential to optimize TFR performance. In order to explain TFR phenomenon chemically, methane oxidation experiments were conducted in a laminar flow reactor with addition of ethanol and methanol at equivalent ratios of 1.5, 1.7, 1.9 and 2.1 from 948K to 1098K at atmospheric pressure. Experimental results showed that methanol have great ability to facilitate the oxidation of methane than that of ethanol. Meanwhile, the degree of methane conversion became more significantly as the equivalent ratio increased. Kinetic analysis of oxidation of methane with alcohol enrichment in a plug flow model was also conducted in this study. There was good agreement between experimental and computational results. The oxidation of methanol or ethanol released plenty of radicals such as H, OH and HO2, which further reacted with CH4 more intensively in fuel rich condition. Rate of production and sensitivity analyses showed that methanol could produce more reactive radicals, which were involved in a series of initial oxidation reactions of methane. It indicated that methanol have great potential to improve in-cylinder TFR performance.
Deng, Zhiwei, Li, Ang, Zhu, Lei, Huang, Zhen
Effect of Hydrogen Fraction on Laminar Flame Characteristics of Methanol-Hydrogen-Air Mixture at Atmospheric Pressure2017-01-227710/8/2017
Methanol has been regarded as a potential transportation fuel due to its advanced combustion characteristics and flexible source. However, it is suffering from misfire and high HC emissions problems under cold start and low load conditions either on methanol SI engine or on methanol/diesel dual fuel engine. Hydrogen is a potential addition that can enhance the combustion of methanol due to its high flammability and combustion stability. In the current work, the effect of hydrogen fraction on the laminar flame characteristics of methanol- hydrogen-air mixture under varied equivalence ratio was investigated on a constant volume combustion chamber system coupled with a schlieren setup. Experiments were performed over a wide range of equivalence ratio of the premixed charge, varied from 0.8 to 1.4, as well as different hydrogen fraction, 0%, 5%, 10%, 15% and 20% (n/n). All tests were carried out at fixed temperature and pressure of 400K and 0.1MPa. The results showed that addition of hydrogen is beneficial for enhancing the combustion process of methanol-air mixture, laminar burning velocity and flame propagation of methanol-air increased significantly with the increasing of hydrogen. The effect of hydrogen addition on the stability of flame depended on equivalence ratio. In the condition of lean burn, the increasing of hydrogen addition deteriorated the stability of the flame. However, when ϕ>1.2, the increasing of hydrogen fraction is able to stabilize the flame. Besides, the effect of equivalence ratio on the stability of flame is accordant for both methanol-air mixture and methanol-hydrogen-air mixture: the flame stability which obtained from Markstein length decreased with the increasing of equivalence ratio. A detailed discussion on the differences between various equivalence ratio and hydrogen fraction of methanol- hydrogen-air mixture combustion in terms of combustion characteristics has been presented.
Peng, Xiao, Wu, Han, Lee, Chia-Fon, Sun, Qianbo, Liu, Fushui
Effects of Biofuels on the Mixture Formation and Ignition Process in Diesel-Like Jets2017-01-233210/8/2017
In order to reduce engine out CO2 emissions it is a main subject to find new alternative fuels out of renewable sources. For this paper, several fuels were selected which can be produced out of biomass or with hydrogen which is generated directly via electrolysis with electricity from renewable sources. All fuels are compared to conventional diesel fuel and two diesel surrogates. It is well known that there can be a large effect of fuel properties on mixture formation and combustion, which may result in a completely different engine performance compared to the operation with conventional diesel fuels. Mixture formation and ignition behavior can also largely affect the pollutant formation. The knowledge of the combustion behavior is also important to design new engine geometries or implement new calibrations for an existing engine. The fuel properties of the investigated fuels comprise a large range, for example in case of the derived cetane number, from below 30 up to 100. In the study described here, different optical diagnostic methods are used simultaneously to monitor the behavior of these fuels. Measurements have been taken in a high pressure vessel at in-cylinder conditions representative for modern diesel engines. To investigate ignition and lift-off length of the fuel jets, high-speed detection of OH*-radicals was applied. In case of mixture formation analysis, Mie scattering measurement technique was used to detect the liquid penetration length and for the gas-phase, a shadowgraphy method was used. For both measurement techniques, a high speed camera was set up. By combining these optical measurement techniques, different amounts of premixed combustion have been observed for the different fuels. This can affect strongly the pollutant formation. Adding oxygen to a fuel increases the lift-off-length significantly at the same ignition delay time. Especially, the investigated fuel OME 3,4,5 seems to be a good alternative candidate regarding its sooting tendency.
Ottenwaelder, Tamara, Pischinger, Stefan
Methanol Fuel Testing on Port Fuel Injected Internal-Only EGR, HPL-EGR and D-EGR ® Engine Configurations2017-01-228510/8/2017
The primary focus of this investigation was to determine the hydrogen reformation, efficiency and knock mitigation benefits of methanol-fueled Dedicated EGR (D-EGR®) operation, when compared to other EGR types. A 2.0 L turbocharged port fuel injected engine was operated with internal EGR, high-pressure loop (HPL) EGR and D-EGR configurations. The internal, HPL-EGR, and D-EGR configurations were operated on neat methanol to demonstrate the relative benefit of D-EGR over other EGR types. The D-EGR configuration was also tested on high octane gasoline to highlight the differences to methanol. An additional sub-task of the work was to investigate the combustion response of these configurations. Methanol did not increase its H2 yield for a given D-EGR cylinder equivalence ratio, even though the H:C ratio of methanol is over twice typical gasoline. Although the methanol H2 reformate yield did not increase over gasoline for a given equivalence ratio, the total yield did increase due to an extended rich misfire limit of the dedicated cylinder. Methanol-fueled D-EGR extended the maximum load of the engine by 2 bar BMEP. It also improved CoV of IMEP, increased dilution tolerance, improved combustion efficiency, and improved thermal efficiency. Cooled EGR also suppressed hot spot pre-ignition of methanol.
Randolph, Eric, Gukelberger, Raphael, Alger, Terrence, Briggs, Thomas, Chadwell, Christopher, Bosquez Jr., Antonio
Effect of Hydrogen Volume Ratio on the Combustion Characteristics of CNG-Diesel Dual-Fuel Engine2017-01-227010/8/2017
CNG-diesel dual fuel combustion mode has been regarded as a practical operation strategy because it not only can remain high thermal efficiency but also make full use of an alternative fuel, natural gas. However, it is suffering from misfire and high HC emissions under cold start and low load conditions. As known, hydrogen has high flammability. Thus, a certain proportion of hydrogen can be added in the natural gas (named HCNG) to improve combustion performance. In this work, the effect of hydrogen volume ratio on combustion characteristics was investigated on an optically accessible single-cylinder CNG-diesel engine using a Phantom v7.3 color camera. HCNG was compressed into the tank under different hydrogen volume ratios varied from 0% to 30%, while the energy substitution rate of` HCNG remained at 70%. The results show that with the increase of hydrogen volume ratios, the peak of in-cylinder pressure and heat release increase significantly, and the crank angles corresponding to the maximum pressure, maximum heat release rate, and cumulative heat release rates of 5%, 20% and 50% advance. With the increase of hydrogen volume ratios, the ignition delay, from main injection timing to initial flame timing, decreases while the number of yellow ignition spots and the yellow ignition area increase. The HCNG has two ways to combustion, which are flame propagation and compression ignition. Based on the flame images, the combustion process can be divided into five phases: (1) ignition delay phase, (2) diesel premixed combustion phase, (3) diesel mixing controlled combustion phase, (4) HCNG premixed combustion phase, (5) remaining diesel mixing controlled combustion phase. Hydrogen has more notable effect on the early combustion than the late phase.
Liu, Fushui, Kang, Yue, Wu, Han, Lee, Chia-Fon, Li, Yikai
Tradeoff Study of High Altitude Solar Reflector Concepts2017-01-21439/19/2017
A direct solution to Global Warming would be to reflect a part of sunlight back into Space. A system tradeoff study is being developed with three of the concepts that are being evaluated as long-endurance high-altitude reflectors. The first concept is a high aspect ratio solar powered flying wing towing reflector sheets. This concept is named “Flying Carpet”. Second is a centrifugally stretched high altitude solar reflector (CSHASR). The CSHASR has 4 rotors made of reflector sheets with a hub stretching to 60 percent of the radius, held together by an ultralight quad-rotor structure. Each rotor is powered by a solar-electric motor. A variation on this concept, forced by nighttime descent rate concerns, is powered by tip-mounted solar panels and propellers with some battery storage augmenting rotational inertia as well as energy storage. The third concept is an Aerostatically Balanced Reflector (ABR) sheet, held up by hydrogen balloons. A set of co-axial counter-rotating rotors provides trim, directional control and migration with the summer Sun. This concept also offers the ability to hold up the reflector at arbitrary orientations to achieve maximum reflection, normal to the slanted rays of the polar summer sun. This paper presents concept evaluation and comparisons, explaining the concepts and high-level features of each concept in this extreme and little-explored regime of rotorcraft aeromechanics as well as aerostatics.
Komerath, Narayanan, Shukla, Dhwanil, Hariharan, Shravan, Patel, Sahaj, Hiremath, Nandeesh
Automotive Engineering: April 201717AUTP044/1/2017
Thought leadership at WCX17 Proliferating electrification and performance. Clarity of purpose Honda's 2017 Clarity Fuel Cell has impressive performance, zero emissions and zero range anxiety. Clarity is ready for the mainstream, but is hydrogen fuel? Lightweighting hinges on the details Multi-material design approaches require careful integration of all adjacent constituents. Haptic feedback for gesture-control HMI Mid-air gesture controls rely on sophisticated sensing to aid the human-machine interface and help keep drivers' eyes on the road. Road-efficient mud machine Jeep's new Compass benefits from a trick AWD system co-developed with GKN. Past as prelude to the future SAE's Mobility History Committee brings a trove of knowledge- and cool technology. The new Fellow from Ricardo Prof. Neville Jackson will be recognized as an SAE Fellow at WCX17. Editorial: The new engineering shortage SAE Standards News Moving EV wireless charging toward a global standard Supplier Eye The new supplier invasion Euro NCAP to adopt autonomous-vehicle ratings Ford sets tech-paper record as SAE boosts quality standard The upside of engine downsizing: senior auto executives give their views New Lexus LC brings new platform, hybrid system 805-hp Mercedes-AMG GT Concept hybrid heralds production model Renault claims Chevy Bolt-beating range for new Zoe EV Phil Guys, AAM's CTO, talks 'radical' Quantum axle
Correlation between Simulated Volume Fraction Burned Using a Quasi-Dimensional Model and Flame Area Measured in an Optically Accessible SI Engine2017-01-05453/28/2017
Multi-fuel operation is one of the main topics of investigative research in the field of internal combustion engines. Spark ignition (SI) power units are relatively easily adaptable to alternative liquid-as well as gaseous-fuels, with mixture preparation being the main modification required. Numerical simulations are used on an ever wider scale in engine research in order to reduce costs associated with experimental investigations. In this sense, quasi-dimensional models provide acceptable accuracy with reduced computational efforts. Within this context, the present study puts under scrutiny the assumption of spherical flame propagation and how calibration of a two-zone combustion simulation is affected when changing fuel type. A quasi-dimensional model was calibrated based on measured in-cylinder pressure, and numerical results related to the two-zone volumes were compared to recorded flame imaging. Gasoline, ethanol, methane and hydrogen were used as fuels and the aforementioned comparison was performed for each case. In order to identify the influence of specific properties, intake pressure, air-fuel ratio and spark timing were kept constant for al fuel types. Overall the spherical flame assumption was found to ensure acceptable results and the correlation between turbulence intensity and flame propagation emphasized the importance of proper description of localized scales at which chemical reactions occur behind the flame front.
Irimescu, Adrian, Di Iorio, Silvana, Merola, Simona Silvia, Sementa, Paolo, Vaglieco, Bianca Maria
Influence of Binary CNG Substitute Composition on the Prediction of Burn Rate, Engine Knock and Cycle-to-Cycle Variations2017-01-05183/28/2017
Since 0D/1D-simulations of natural gas spark ignition engines use model theories similar to gasoline engines, the impact of changing fuel characteristics needs to be taken into consideration in order to obtain results of higher quality. For this goal, this paper proposes some approaches that consider the influence of binary fuel mixtures such as methane with up to 40 mol-% of ethane, propane, n-butane or hydrogen on laminar flame speed and knock behavior. To quantify these influences, reaction kinetics calculations are carried out in a wide range of the engine operation conditions. Obtained results are used to update and extend existing sub-models. The model quality is validated by comparing measured burn rates with simulation results. The benefit of the new sub-models are utilized by predicting the influence the fuel takes on engine operating limits in terms of knocking and lean misfire limits, the latter being determined by using a cycle-to-cycle variation model.
Hann, Sebastian, Urban, Lukas, Grill, Michael, Bargende, Michael
Laminar Burning, Combustion and Emission Characteristics of Premixed Methane- Dissociated Methanol-Air Mixtures2017-01-12893/28/2017
This research presents an experimental study of the laminar burning combustion and emission characteristics of premixed methane -dissociated methanol-air mixtures in a constant volume combustion chamber. All experiments were conducted at 3 bar initial pressure and 373K initial temperature. The dissociated methanol fractions were from 20% to 80% with 20% intervals, and the equivalence ratio varied from 0.6 to 1.8 with 0.2 intervals. The images of flame propagation were visualized by using a schlieren system. The combustion pressure data were measured and exhaust emissions were sampled with a portable exhaust gas analyzer. The results show that the unstretched laminar burning velocities increased significantly with dissociated methanol enrichment. The Markstein length decreased with increasing dissociated methanol fraction and decreasing equivalence ratio. The lewis number decreased with increasing dissociated methanol fraction due to the enhancing of diffusional thermal instability and hydrodynamic instability. The highest maximum combustion pressure was observed when the equivalence ratio was around 1.2 with 80% dissociated methanol added. The ignition delay time decreased with increasing dissociated methanol fraction. As the fraction of dissociated methanol increased in the mixtures, HC and CO2 decreased but CO and NOX increased.
Liu, Bin, Hu, Tie Gang, Zhong, Jing, Zuo, Zinong, Pei, Yiqiang, Qin, Jing, Jia, Ruoyu, Li, Xiang, ZHAN, Zhang Song
Development of Laminar Burning Velocity Correlation for the Simulation of Methanol Fueled SI Engines Operated with Onboard Fuel Reformer2017-01-05393/28/2017
Methanol fueled spark ignition (SI) engines have the potential for very high efficiency using an advanced heat recovery system for fuel reforming. In order to allow simulation of such an engine system, several sub-models are needed. This paper reports the development of two laminar burning velocity correlations, corresponding to two reforming concepts, one in which the reformer uses water from an extra tank to produce hydrogen rich gas (syngas) and another that employs the water vapor in the exhaust gas recirculation (EGR) stream to produce reformed-EGR (R-EGR). This work uses a one-dimensional (1D) flame simulation tool with a comprehensive chemical kinetic mechanism to predict the laminar burning velocities of methanol/syngas blends and correlate it. The syngas is a mixture of H2/CO/CO2 with a CO selectivity of 6.5% to simulate the methanol steam reforming products over a Cu-Mn/Al catalyst. The simulation was exercised over syngas contents in the blend, fuel-air equivalence ratios, pressures, unburned gas temperatures and EGR ratios ranging respectively from 0% to 50%, 0.5 to 1.5, 10 to 85 bar, 550 to 800 K and 0% to 30% (by mass). The developed correlations are ready to be implemented into engine simulation tools as well as computational fluid dynamic codes. Based on the developed correlations, optimal control strategies and dilution methods have been studied. The engine is able to work with the same mass burning rate at leaner mixtures or lower intake charge temperatures with an onboard fuel reformer. If the engine is operated at stoichiometric condition, at the same mass fraction of methanol to the catalyst and the same EGR, the R-EGR concept is recommended because it provides a faster laminar burning velocity and does not require an extra tank of water for fuel reforming.
Nguyen, Duc-Khanh, Verhelst, Sebastian
A General Selection Method for the Compressor of the Hydrogen Internal Combustion Engine with Turbocharger2017-01-10253/28/2017
Hydrogen is a promising energy carrier because it is characterized by a fast combustion velocity, a wide range of sources, and clean combustion products. A hydrogen internal combustion engine (H2ICE) with a turbocharger has been used to solve the contradiction of power density and control NOx. However, the selection of a H2ICE compressor with a turbocharger is very different from traditional engines because of gas fuel. Hydrogen as a gas fuel has the same volume as its cylinder and thus increases pressure and reduces the mass flow rate of air in cylinder for a port fuel injection-H2ICE (PFI-H2ICE). In this study, a general method involving a H2ICE with a turbocharger is proposed by considering the effect of hydrogen on cylinders. Using this method, we can calculate the turbocharged pressure ratio and mass flow rate of air based on the target power and general parameters. This method also provides a series of intake temperatures of air before calculation to improve accuracy. The calculated compressor outlet temperatures are compared with the theoretical temperatures to obtain accurate data. A fit compressor is selected for a 2.3 L H2ICE and the engine is tested at different engine speed and throttle openings to validate the correctness of this method. The error is below 5% when the experimental turbocharging pressure ratio and mass flow rate of air are compared with the calculated results, and this error is acceptable. Therefore, this method can be used as a basis for the designing and selection of H2ICE compressors.
Luo, Qinghe, Sun, Baigang, Wang, Xi
Unsteady Three-Dimensional Computations of the Penetration Length and Mixing Process of Various Single High-Speed Gas Jets for Engines2017-01-08173/28/2017
For various densities of gas jets including very light hydrogen and relatively heavy ones, the penetration length and diffusion process of a single high-speed gas fuel jet injected into air are computed by performing a large eddy simulation (LES) with fewer arbitrary constants applied for the unsteady three-dimensional compressible Navier-Stokes equation. In contrast, traditional ensemble models such as the Reynolds-averaged Navier-Stokes (RANS) equation have several arbitrary constants for fitting purposes. The cubic-interpolated pseudo-particle (CIP) method is employed for discretizing the nonlinear terms. Computations of single-component nitrogen and hydrogen jets were done under initial conditions of a fuel tank pressure of gas fuel = 10 MPa and back pressure of air = 3.5 MPa, i.e., the pressure level inside the combustion chamber after piston compression in the engine. An important point of the present study is to obtain clear evidence for Hamamoto’s experimental data that the penetration length of a light hydrogen gas jet of low density is nearly the same as that of relatively heavy gas jets such as nitrogen or carbon dioxide. It is confirmed that the computed penetration lengths of hydrogen and nitrogen gas jets injected into air are nearly the same, although hydrogen has very small inertia due to its low density. It is also stressed that computational results agree fairly well with Hamamoto’s empirical data on penetration lengths and diffusion area in the direction normal to the jet axis. Moreover, computations based on the present LES also clarify a physical mechanism underlying combustion instability in engine experiments conducted by Takagi et al., although the RANS is relatively difficult to reveal instability of unsteady flow field.
Konagaya, Remi, Naitoh, Ken, TSURU, Kohta, Takagi, Yasuo, Mihara, Yuji
Preliminary Design of a Cryogenic Hydrogen Radiation Shield for Human SpaceflightTBMG-263302/1/2017
Human susceptibility to the harsh space radiation environment has been identified as a major hurdle for exploration beyond low-Earth orbit (LEO). High-energy protons and nuclei ions from Solar Energetic Particles (SEPs) and Galactic Cosmic Rays (GCRs) can result in radiation doses that are dangerous to astronaut health and even survivability if the astronauts are not adequately shielded. These high-energy particles also cause significant amounts of secondary radiation when they impinge on the spacecraft structure. Hydrogen or hydrogen-rich materials are ideal materials for radiation shielding because hydrogen does not easily break down to form a secondary radiation source.
Reforming Controlled Homogenous Charge Compression Ignition -Simulation Results2016-32-001411/8/2016
A computer model was built and a theoretical analysis was performed to predict the behavior of a system containing Homogenous charge compression ignition (HCCI) engine and a methanol reformer. The reformer utilizes the waste heat of the exhaust gases to sustain the two subsequent processes: dehydration of methanol to dimethyl ether (DME) and water, and methanol steam reforming (SRM) where methanol and water react to mainly hydrogen, CO and CO2. Eventually, a gaseous mixture of DME, H2, CO, CO2, water (reused) and some other species is created in these processes. This mixture is used for the engine feeding. By adding water to the methanol and fixing the vaporized fuel's temperature, it is possible to manage the kinetics of chemical processes, and thus to control the products’ composition. This allows controlling the HCCI combustion. By a magnification of H2/DME ratio the ignition delay is increased and so it is possible to synchronize the ignition timing and also to control combustion duration. The simulation results prove feasibility of the suggested approach and a possibility of achieving substantially higher energy efficiency together with zero-impact NOx emissions in a wide range of engine operating modes.
Eyal, Amnon, Tartakovsky, Leonid
Improved Thermal Efficiency using Hydrous Ethanol Reforming in Advanced Spark-Ignition Engines2016-01-226210/17/2016
Bio-ethanol can be produced from several type of biomass, and the CO2 emission of bio-ethanol is low compared with gasoline. Bio-ethanol is a high octane fuel, therefore, it has characteristics that allow it to burn at a high compression ratio condition. However, bio-ethanol is usually refined to be high purity ethanol (>99.5%). It requires much energy to refine; thus large-scale refinery plants are needed, increasing the cost of refining bio-ethanol. High purity ethanol (>99.5%) can be refined after fermentation and a distillation. If hydrous ethanol can be used as a fuel for engines, the distillation process can be simplified. As a result, the costs of refinement can be reduced. An innovated engine can be developed by using hydrous ethanol as the fuel because three highly efficient methods can be combined. First, exhaust heat can be recovered by the steam reforming of hydrous ethanol. Second, the reformed gas, which contains hydrogen, can be combusted under dilute conditions. Third, it is cooled by directly injecting hydrous ethanol into the engine. In other words, it is possible to burn at a high compression ratio. For all of these reasons, using hydrous ethanol is effective from both perspectives of refining and use. In this study, we examined improvements to thermal efficiency by using hydrous ethanol that was reformed in a spark ignition engine through experimental analysis. First, we experimentally evaluated the effects of reformed gas on the thermal efficiency and exhaust emission under supercharging lean burn and high compression ratio. Second, we evaluated an engine system installed reformer. Such a fuel-reforming engine using hydrous ethanol (60% water content in ethanol) can achieve 45% thermal efficiency.
Shimada, Atsushi, Shirakawa, Yuzo, Ishikawa, Takao
Evaluation of Hydrous Ethanol Fuel Lubricity by HFRR2016-01-226010/17/2016
Improvement of thermal efficiency is an important problem for internal combustion engines. Fuel reforming with dehydrogenation reaction by exhaust heat is one of the measures to increase thermal efficiency using hydrogen mixed SI combustion. For this kind engine system, hydrous ethanol has a good potential. Furthermore, when the hydrous ethanol inject to combustion chamber directory, high compression combustion can be achieved by its large amount of latent heat. Therefore, fuel lubricity is an important check point for the hydrous ethanol reforming engine systems. In this study, effect of water concentrations within ethanol on the hydrous ethanol fuel lubricity has been evaluated using HFRR (High-Frequency Reciprocating Rig) test method. Wear scar diameter on 100 % of ethanol was around 700 μm which was a little better than gasoline lubricity. When the water concentration within ethanol was increased, the wear scar diameters were decreasing around 330 μm. Considering this phenomenon by the fuel viscosity, the viscosity of hydrous ethanol is growing with increasing water concentration up to 50-60 %. It seems that lubricity of hydrous ethanol can be kept by fluid film lubrication mode up to 50-60 % of water concentration.
Oguma, Mitsuharu, Matsuno, Mayumi, Kaitsuka, Masayoshi, Higurashi, Kazuaki
Simulation of the Effect of Initial Temperature and Fuel Injection Pressure on Hydrogen Combustion Characteristics in Argon-Oxygen Compression Ignition Engine2016-01-222710/17/2016
Hydrogen fuel is a potential energy source for vehicles in the future. The emission of this fuel complies with the stringent policies issued by the International Energy Agency (IEA). Researchers have nominated the hydrogen compression ignition engine in an argon atmosphere as one of the ways to enhance power output and volumetric efficiency in the midst of pre-ignition and knock problems. Since this type of research is still in the initial stage, numerical studies have become the best method for researchers to obtain data on hydrogen fuel combustion in an argon-oxygen atmosphere. The purpose of this study was to validate the simulation results with the experimental data, investigate the combustion characteristics of hydrogen fuel in an argon-oxygen atmosphere, and to study the effects of the initial temperature and injection pressure on the combustion process. In this research, CONVERGE CFD software was used for the simulation process. When the ambient temperature increased, there was a decrease in the pressure but an increase in the heat release rate. On the other hand, when the injection pressure was increased, the in-cylinder pressure and the heat release rate decreased slightly.
Hafiz, Nik Muhammad, Mansor, Mohd Radzi Abu, Wan Mahmood, Wan Mohd Faizal, Shioji, Masahiro
CryoFOSS Optical Sensor Offers Next-Level Liquid MeasurementTBMG-2561810/1/2016
NASA engineer Allen Parker and a team at Armstrong Flight Research Center have developed a fiber-optic-based sensing technology that accurately pinpoints and measures liquid levels. The CryoFOSS, or Cryogenic Fiber Optic Sensing System, uses fiber optic Bragg sensors, located along a single cable, to actively discern between liquid and gas states. The technology can be employed in a variety of applications, from NASA’s rockets to a winery’s storage tanks.
Energy Storage for Commercial Hybrid Electric Aircraft2016-01-20149/20/2016
Energy storage options for a hybrid electric commercial single aisle aircraft were investigated. The propulsion system features twin Geared Turbofan™ engines in which each low speed spool is assisted by a 2,500 HP electric motor during takeoff and climb. During cruise, the aircraft is powered solely by the turbine engines which are sized for efficient operation during this mission phase. A survey of state of the art energy storage options was conducted. Battery, super-capacitor, and flywheel metrics were collected from the literature including Specific Energy (Wh/kg), Volumetric Energy Density (Wh/L), Specific Power (W/kg), Cost ($/kWh), and Number of Cycles. Energy storage in fuels was also considered along with various converters sized to produce a targeted quantity of electric power. The fuel and converters include fuel cells (both proton exchange membrane and solid oxide operating on hydrogen or on jet fuel) and a turbogenerator (jet fuel or LNG). The various energy storage options were compared across a range of stored energy on the basis of weight. The selection of a lightweight energy storage technology depends on power and quantity of energy storage. A turbogenerator auxiliary power unit has the best energy and power density for the application. The fuel cells tend to be heavy options due to low specific power. PEM fuel cells operating on compressed or liquid hydrogen are lighter weight than SOFCs, however, PEMFCs are comparable to batteries at the energy storage design point of 1500 kWh. Applications requiring low detectability and long duration favor PEM fuel cells.
Rheaume, Jonathan M., Lents, Charles
Temperature Oscillations in the Wall of a Cooled Multi Pulsejet Propeller for Aeronautic Propulsion2016-01-19989/20/2016
Environmental and economic issues related to the aeronautic transport, with particular reference to the high-speed one are opening new perspectives to pulsejets and derived pulse detonation engines. Their importance relates to high thrust to weight ratio and low cost of manufacturing with very low energy efficiency. This papers presents a preliminary evaluation in the direction of a new family of pulsejets which can be coupled with both an air compression system which is currently in pre-patenting study and a more efficient and enduring valve systems with respect to today ones. This new pulsejet has bee specifically studied to reach three objectives: a better thermodynamic efficiency, a substantial reduction of vibrations by a multi-chamber cooled architecture, a much longer operative life by more affordable valves. Another objective of this research connects directly to the possibility of feeding the pulsejet with hydrogen. This paper after a preliminary analysis of the pulsejet takes into account two necessary stages of this activity with the initial definition of the starting point of this activity, which aim to define an initial thermodynamic balance of a Lenoir cycle and a preliminary but effective estimation of the thermal problem. It analyses the heat transfer process through the wall of the combustion chamber of a pulsejet for aeronautic propulsion. The inside wall is exposed to burning gases with an average temperature of 1500 K, which oscillates with an amplitude 500 k and a frequency of 50 Hz. It has been considered the possibility of using Hydrogen injection to reduce the environmental impacts at the price of introducing a cooling water envelope at an average temperature of 80 °c. The water mass flow to ensure this condition has been evaluated and it has been evaluated both the average temperature profile within the wall and the effects of the oscillations of gas temperature inside the combustion chamber. Obtained results have allowed starting an effective activity through a radically new pulsejet architecture, which is expected to outclass any former pulsejet in term of operative life and of compression ratio with a consequent step increase in terms of thermodynamic efficiency.
Trancossi, Michele, Pascoa, Jose, Xisto, Carlos
Growth of FCVs and EVs tied to infrastructure16AUTP08_078/1/2016
More hydrogen fueling stations in California and additional electric vehicle charging stations across the U.S. could reduce the range anxiety consumers have about driving these-advanced technology vehicles, Bill Elrick, Executive Director of the California Fuel Cell Partnership told an xEV Infrastructure session audience at the 2016 Advanced Automotive Battery Conference in Detroit. “You can't sell a car if there isn't infrastructure to support it,” Elrick flatly stated.
Buchholz, Kami
Control Solutions Synchronize Operation of Space Launch System Heavy TransportersTBMG-248886/1/2016
Control panels, embedded PCs, automation software, and servomotors and drives Beckhoff Automation Savage, MN 952-890-0000
Investigation of Fuel Effects on In-Cylinder Reforming Chemistry Using Gas Chromatography2016-01-07534/5/2016
Negative Valve Overlap (NVO) is a potential control strategy for enabling Low-Temperature Gasoline Combustion (LTGC) at low loads. While the thermal effects of NVO fueling on main combustion are well-understood, the chemical effects of NVO in-cylinder fuel reforming have not been extensively studied. The objective of this work is to examine the effects of fuel molecular structure on NVO fuel reforming using gas sampling and detailed speciation by gas chromatography. Engine gas samples were collected from a single-cylinder research engine at the end of the NVO period using a custom dump-valve apparatus. Six fuel components were studied at two injection timings: (1) iso-octane, (2) n-heptane, (3) ethanol, (4) 1-hexene, (5) cyclohexane, and (6) toluene. All fuel components were studied neat except for toluene - toluene was blended with 18.9% nheptane by liquid volume to increase the fuel reactivity. Additionally, a gasoline surrogate matching the broad molecular composition of RD587 gasoline was formulated using the chosen fuel palette and tested. The energy content of the injected fuel mass was kept constant for the sampled NVO cycle and the excess oxygen was relatively low (2.4%) compared to previous studies by the authors. The later injection timing studied resulted in useable recovered fuel energy near 70% and improved reformate yield of hydrogen and C1-C4 hydrocarbons compared to the earlier injection timing for all fuels except toluene/n-heptane. Analysis of the RD587 surrogate reformate compared to the individual component reformates suggests that fuel component interactions depend on injection timing, potentially through the in-cylinder equivalence ratio distribution.
Wolk, Benjamin, Ekoto, Isaac, Northrop, William
Ignition Delay Correlation for Engine Operating with Lean and with Rich Fuel-Air Mixtures2016-01-06994/5/2016
An ignition delay correlation encompassing the effects of temperature, pressure, residual gas, EGR, and lambda (on both the rich and lean sides) has been developed. The procedure uses the individual knocking cycle data from a boosted direct injection SI engine (GM LNF) operating at 1250 to 2000 rpm, 8-14 bar GIMEP, EGR of 0 to 12.5%, and lambda of 0.8 to 1.3 with a certification fuel (Haltermann 437, with RON=96.6 and MON=88.5). An algorithm has been devised to identify the knock point on individual pressure traces so that the large data set (of some thirty three thousand cycles) could be processed automatically. For lean and for rich operations, the role of the excess fuel, air, and recycled gas (which has excess air in the lean case, and hydrogen and carbon monoxide in the rich case) may be treated effectively as diluents in the ignition delay expression.
McKenzie, Jacob, Cheng, Wai K.
Hydrocarbon Speciation of Diesel Ignited Ethanol and Butanol Engines2016-01-07734/5/2016
Dual fuel applications of alcohol fuels such as ethanol or butanol through port injection with direct injection of diesel can be effective in reduction of NOx. However, these dual fuel applications are usually associated with an increase in the incomplete combustion products such as hydrocarbons (HC), carbon monoxide (CO), and hydrogen (H2) emissions. An analysis of these products of incomplete combustion and the resulting combustion efficiency penalty was made in the diesel ignited alcohol combustion modes. The effect of EGR application was evaluated using ethanol and butanol as the port injected fuel, with varying alcohol fractions at the mid-load condition (10 -12 bar IMEP). The impact of varying the engine load (5 bar to 19 bar IMEP) in the diesel ignited ethanol mode on the incomplete combustion products was also studied. Emission measurements were taken and the net fuel energy loss as a result of the incomplete combustion was estimated. Hydrocarbon speciation and hydrogen concentration of the exhaust gas were performed by a Fourier Transform Infrared (FTIR) spectrometry gas analyzer system and a mass spectrometer respectively. Results suggested that the CO and smoke emissions rose monotonically with the application of EGR for all test conditions. While the H2 contribution to combustion inefficiency was largely insensitive to the alcohol fraction and insignificant (less than 1%), the contribution of CO and HC increased when more alcohol was used (up to 20 g/kWh and 3 g/kWh for ethanol-diesel respectively, up to 20 g/kWh and 2.5 g/kWh for butanol-diesel respectively). Analysis of the unburnt hydrocarbon species suggested that for ethanol dual fuel application, a majority of the combustion efficiency penalty could be attributed to the unburnt ethanol (between 30 to 40%). Whereas, when butanol was used, heavier HC species contributed to the combustion efficiency loss (between 30 to 50%).
Dev, Shouvik, Divekar, Prasad, Yanai, Tadanori, Chen, Xiang, Zheng, Ming
Non-Intrusive, On-Line, Simultaneous Multi-Species Impurity Monitor for Hydrogen GasTBMG-2328011/1/2015
In testing hydrogen-fueled engines, the purity of the hydrogen fuel is important. Hydrogen may become contaminated with nitrogen (N2), argon (Ar), or oxygen (O2), thereby making the hydrogen unusable for engine testing at Stennis Space Center (SSC). Therefore, for rocket engine testing, the quality of hydrogen from the fuel tank or feed line is tested before use. If there are contaminants found within the hydrogen, it is mandatory for the tank to be emptied; this results in testing delay. Therefore, NASA has specific interest in measuring concentrations of N2, Ar, and O2 in hydrogen gas. The approach currently used for testing the purity of hydrogen is conducted by collecting a gas sample from the hydrogen supply line or storage tank and then sending it to an analytical laboratory for evaluation. This procedure is time consuming and can, if the sampling is not carefully conducted, inadvertently introduce contamination, which would provide a misguided reading for the entire tank. Therefore, establishing a non-intrusive, on-line, near-real-time monitor that has a simultaneous multi-species impurity detection capability for hydrogen would eliminate these issues.
Novel Feedthrough for Instrumentation Lead WiresTBMG-2302510/1/2015
This invention is a method and design for the conveyance of instrumentation lead wires from one pressure boundary to another pressure boundary in cryogenic process systems. Such a device or article is commonly referred to as a feedthrough. The novelty of the present invention is the extreme low-temperature conditions commensurate with extreme leak-tightness requirements that are managed by a relatively simple and economical approach. The design is directly applicable to any process system or instrumentation device operating below approximately 300°F. The novel feedthrough design is very cost-effective and easy to produce, yet provides solutions to sealing problems under severe conditions or for extremely demanding requirements.
Evaluation of H 2 /N 2 as an Alternative to H 2 /He for Flame Ionization Detector Mix Fuel2015-01-28039/29/2015
The Flame Ionization Detection (FID) is the most sensitive and widely used technology for the measurement of total hydrocarbons (THC). In the automotive emission testing of hydrocarbons, the fuel used for the flame in the FID analyzer is a mixture of hydrogen and helium in the ratio of 40:60. The Environmental Protection Agency (EPA) revised 40CFR part 1065 in April 2014 to include nitrogen as a balance gas alternative to helium for FID fuel mixtures used in the automotive industry. In addition to the balance gas alternative, the FID fuel blend tolerance was decreased from 40±2% to 40±1% (0.39 to 0.41mol/mol) hydrogen to minimize the impact on analyzer response. The feasibility of nitrogen as a FID fuel balance gas was studied and compared with a helium balance gas to understand the relative impact on emission testing. The study evaluated multiple hydrogen concentrations ranging from 38-42% in both balance gases. The FID fuel was also evaluated to determine the impact of hydrocarbon contamination (0-100ppb) on the instrumental response. Hydrocarbon detection was found to be more sensitive to deviations in the fuel composition with nitrogen as a balance gas than with helium. With hydrogen composition at 40±1%, the FID response drifts up to ±6% with nitrogen compared to ±2% with helium as the balance gas. It was observed that the accuracy of the hydrocarbon analysis could be improved further by reducing the blend tolerance of hydrogen with nitrogen as a balance gas relative to helium. Background research on the impact of nitrogen as a balance gas is limited and this evaluation is aimed to study the potential of nitrogen as a replacement to helium in the coming years for FID analyses.
Kumar, Anuj, Rougé, Valentin, Luu, Nathalie, Yu, Steven, Bossoutrot, Valerie, Hagen, Steve, Jacksier, Tracey
Modelling of Distributed-Propulsion Low-Speed HALE UAVs Burning Liquid Hydrogen2015-01-24679/15/2015
The present work focuses on developing an integrated airframe, distributed propulsion, and power management methodology for liquid-hydrogen-fuelled HALE UAVs. Differently from previous studies, the aim is to assess how the synergies between the aforementioned sub-systems affect the integrated system power requirement, production, and distribution. A design space exploration study was carried out to assess the influence of distributing motor-driven fans on three different airframes, namely a tube-and-wing, a triple-fuselage, and a blended-wing-body. For the considered range of take-off masses from 5,000 to 15,000 kg, the 200 kW payload power requirement under examination was found to re-shape the endurance trends. In fact, the drop in specific fuel consumption due to the engine design point change alters the trends from nearly flat to a 25% maximum endurance increase when moving towards heavier take-off masses. For the selected distributed propulsion system, the BWB airframe was found to improve endurance by approximately 30% compared to the other designs, and no apparent benefit was found with the triple-fuselage airframe for the present application.
Gallo, Luca, Tashie-Lewis, Bernard, Laskaridis, Panos, Miller, Paul, Husband, Mark
Estimation of the Composition of Methane-Hydrogen Mixtures from Engine Control Variables2015-24-24939/6/2015
Low Carbon fuels will play a relevant role in the transportation sector contributing, over the powertrain technology progress, to mitigate global CO2 emissions. Compressed Natural Gas (CNG), mainly composed by methane, is one of the best candidate thanks to its chemical composition and to its wide diffusion and use. Blending Hydrogen in Natural Gas could represent a further step for a better CO2 footprint (considering renewable or biohydrogen) but also to optimize the combustion process, increasing the engine thermal efficiency and reducing pollutant formation. On the other hand, capability to automatically adapt the engine parameters to variable concentrations of Hydrogen in Natural Gas (in the range from 0% to 40% by volume) is a mandatory step to maintain engine performance, emissions and efficiency The activities described in this paper are part of a large collaborative project, “Biomethair”, funded by Regione Piemonte, where material specifications on gas tanks, valves, feeding lines, gas pressure regulator, engine pipes and injectors have been set and prototype components procured and implemented into the demonstrator vehicle to ensure safe operating conditions. In this paper a software algorithm is presented, able to provide, during normal car operation, real time estimates of methane-hydrogen composition, allowing the engine control system to adapt the control parameters engine. The algorithm is based on the innovative data-driven technology Direct Virtual Sensor, which allows to design the Virtual Sensor from the experimental data collected from a testing car, subject to suitable manoeuvres in different operational conditions, without requiring deep first principle modelling of the involved systems. The Virtual Sensor has been designed and implemented on the Electronic Control Unit of the demonstrator vehicle, giving suitably discretized estimates of Methane-Hydrogen composition, using measurements of engine revolution speed, of the lambda probe value and a variable from engine control unit. Experimental results of the Virtual Sensor performance evaluated in different operational conditions are presented.
Milanese, Mario, Bonansone, Mario
Comparison of the Flame Propagation Behavior of Lean and Diluted Mixtures in a Constant Volume Chamber2015-01-18759/1/2015
In this study, the effects of equivalence ratio and nitrogen dilution on laminar burning velocity were studied for propane/air/nitrogen mixtures. The stretched laminar burning velocity of mixtures was determined from the measured pressure histories in a constant volume spherical chamber. The effect of stretch rate on the laminar burning velocity was analyzed using linear and nonlinear methods. The laminar burning velocities of the diluted mixtures decreased with an increase in volume percent of nitrogen dilution. The laminar burning velocity of diluted mixtures was lower than that of lean mixtures in the same propane concentration.
Shibata, S., Sasaki, K., Uesaka, H., Kataoka, H., Segawa, D., Kadota, T.
A Theoretical Approach of UNIT (Unified Nuclear Integral Technology) Propulsion and its Potential for Future Applications in Space Exploration2015-01-90049/1/2015
Space exploration is the present inevitable challenge for researchers. Various theoretical propulsion concepts have been evolved over the past years for space missions. Their potential remains as a key factor for the spacecraft to travel deeper into space in a shorter mission duration. The propulsion concept UNIT is an integrated nuclear propulsion technique that provides high entry, descent and landing (EDL) performance in such short duration to conquer other galaxies. This paper describes the theoretical approach of the UNIT propulsion system in detail. UNIT produces the highest energy possible by consuming nuclear fuel and possess the highest potential that opens new opportunities for space exploration. The principle is that the neutrons from the fusion are deliberately allowed to induce fission. It uses National Ignition Facility's laser beam for inertial confinement fusion followed by utilizing the power from tubular solid fuel cell. Thus, the net thrust is produced from the expansion of the combined plasma of the nuclear fusion and nuclear fission reactions through the nozzle.
Dran, Sarath Ramachan
Heat Release Rate and Cylinder Gas Pressure Oscillation in Low and High Speed Knock2015-01-18809/1/2015
One of the authors has proposed to use the decay rate of EHRR, the effective heat release rate, d2Q/dθ2 as an index for the rapid local combustion [1]. In this study, EHRR profiles and the cylinder gas pressure oscillations of the low and high speed knock are analyzed by using this index. A delayed rapid local combustion, such as an autoignition with small burned mass fraction can be detected. In the cases of the low speed knock, it has been agreed that a rapid local combustion is an autoignition. Although whether the cylinder gas oscillation is provoked by an auto ignition in a certain cycle or not is an irregular phenomenon, the auto ignition takes place in almost all of the cycles in the knocking condition. Mixture mass fraction burned by an auto ignition is large. A small auto ignition may induce a secondary auto ignition, in many cases, mass burned by the secondary auto ignition is extremely large. On the other hand, in the cases of the high speed knock, it has not been confirmed that the rapid local combustion is an auto ignition. An intense cylinder gas pressure oscillation is provoked in most of the cycles in the knocking condition, and standing wave at the edges in combustion chamber, may induce a cylinder gas pressure oscillation even in the non-knocking cycles. A mixture mass fraction burned by a rapid local combustion seems to be small and give no influence to the EHRR profile.
Ando, Hiromitsu, Nishiyama, Atsushi, Wachi, Yoshihiro, Kuwahara, Kazunari, Sakai, Yasuyuki, Ohta, Takashi
Optimal Energy Management of Hybrid Fuel Cell Electric Vehicles2015-01-13594/14/2015
An optimal energy management system is presented to minimize hydrogen utilization over driving cycles using forward dynamic programming (FDP). The objective is to minimize the cost of hydrogen with the battery cost being used as a parameter to carry out charge-depleting as well as charge-sustaining strategies along with bound enforcement or relaxation. The problem formulation accounts for the power balance at each stage, the power limits, the state-of-charge limits, and the ramp rates constraints of the fuel cell and battery. FDP is selected because it can easily cater for non-linearity in system cost and constraints. It employs heuristic rules to limit the number of states at each stage and is shown to be a very fast algorithm using simple computations and thus may easily lend itself for real-time implementation. Charge sustained operation is obtained by enforcement of the lower bound on the SOC, and charge depletion operation is obtained by lowering the bound to the required depletion level. In both cases a battery cost parameter is set to a value lower than the incremental cost of the fuel cell calculated at the average load of the car for the given drive cycle. Verification of the code is provided by comparing it to results obtained using quadratic programming. Results on practical vehicle designs proposed in the literature are presented for the UDDS and HWFET standard driving cycles.
Karaki, Sami H., Jabr, Rabih, Chedid, Riad, Panik, Ferdinand
Study of an On-board Fuel Reformer and Hydrogen-Added EGR Combustion in a Gasoline Engine2015-01-09024/14/2015
To improve the fuel economy via high EGR, combustion stability is enhanced through the addition of hydrogen, with its high flame-speed in air-fuel mixture. So, in order to realize on-board hydrogen production we developed a fuel reformer which produces hydrogen rich gas. One of the main issues of the reformer engine is the effects of reformate gas components on combustion performance. To clarify the effect of reformate gas contents on combustion stability, chemical kinetic simulations and single-cylinder engine test, in which hydrogen, CO, methane and simulated gas were added to intake air, were executed. And it is confirmed that hydrogen additive rate is dominant on high EGR combustion. The other issue to realize the fuel reformer was the catalyst deterioration. Catalyst reforming and exposure test were carried out to understand the influence of actual exhaust gas on the catalyst performance. Fresh catalyst showed good performance in generating hydrogen, but an aged catalyst generated only half as compared to a fresh catalyst. So we considered measures to improve catalyst performance. According to EGR reforming performance test with single-cylinder engine using conventional catalyst and an improved catalyst, the improved catalyst showed good performance. Finally, in order to confirm the performance of hydrogen generation and the effects of real reformate gas on EGR combustion, a single-cylinder engine with the fuel reformer was developed. It is confirmed that hydrogen is generated from gasoline and EGR gas by the fuel reformer, and combustion stability under high EGR rate is enhanced by reformate hydrogen.
Ashida, Koichi, Maeda, Hirofumi, Araki, Takashi, Hoshino, Maki, Hiraya, Koji, Izumi, Takao, Yasuoka, Masayuki
Fuel-Independent Particulate Emissions in an SIDI Engine2015-01-10814/14/2015
The fuel-independent particulate emissions of a direct injection gasoline engine were investigated. This was done by running the engine with reference gasoline at four different loads and then switching to hydrogen or methane port fuel operation and comparing the resulting particulate emissions and their size distribution. Differences in the combustion characteristics of hydrogen and gasoline were accounted for by diluting the inlet air with nitrogen and matching the pressure or heat release traces to those of gasoline operation. Methane operation is expected to generate particulate emissions lower by several orders of magnitude compared to gasoline and hydrogen does not contribute to carbon soot formation because of the lack of carbon atoms in the molecule. Thus, any remaining particulate emissions at hydrogen gas operation must arise from non fuel related sources, e.g. from lubrication oil, metal abrasion or inlet air. With methane and hydrogen operation, only a very small amount of particles larger than 30 nm could be measured. The comparison between CEC reference fuel and hydrogen operation showed similar size distributions for particles smaller than 10 nm at low loads, which was also consistent with the comparison between methane and gasoline operation. The tentative conclusion is that particles smaller than 10 nm do not, for the most part, originate from the combustion of the fuel. However, at higher loads, the differences between gasoline and hydrogen operation were more pronounced at all particle sizes. Thus, while there seems to be a fuel-independent baseline of particulate emissions, the contribution of the fuel combustion itself is also important and is the dominant contribution at higher engine loads.
Maier, Axel, Klaus, Ulrike, Dreizler, Andreas, Rottengruber, Hermann
Friction Behavior of Diamond-Like Carbon Coated Ball Joint: Approach to Improving Vehicle Handling and Ride-Comfort2015-01-15074/14/2015
Research to respond to demands for improving usability of passenger vehicles has played important roles. Some aspects can be attributed to friction behavior of the steering and suspension components. In this study, we focus on an approach to improve handling, steering feel and ride-comfort of a vehicle by applying the appropriate friction behavior to tie-rod end ball joint. To control not only friction coefficient but also static-kinetic transient behavior, we investigate the potential use of diamond-like carbon (DLC) coatings. Different DLC coatings varied widely in hydrogen content, mechanical properties and micro-surface roughness are applied to the ball studs. Friction behavior corresponds to material characteristics and surface roughness of DLC. The “polymer-like” DLC with higher hydrogen tend to show higher kinetic friction and remarkable stick-slip behavior at the static-kinetic transient period, whereas the “graphite-like” DLC with lower hydrogen show lower kinetic friction and smooth transient behavior. From dynamic evaluation results of actual vehicle, the “graphite-like” DLC gives an appropriate friction behavior for the ball joint, leading to an improved steering feel, vehicle stability and ride-comfort. In contrast, the excessive friction causes a sticky steering feel and an increased harshness with high frequency vibration. We discuss the effectiveness in friction behavior of DLC-coated ball joints depending on the DLC coating properties, with either positive or negative effects found for vehicle handling and ride-comfort.
Komori, Kentaro, Nagataki, Takahito
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