Browse Topic: Compressed natural gas

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Resonator design study to reduce pressure pulsation from CNG Injector2024-26-023301/16/2024
With the advent of upcoming stringent automobile emission norms globally, it is inevitable for OEMs to shift towards greener alternatives. Use of CNG is a preferred solution as it is a relatively clean burning fuel and it doesn’t have significant loss in vehicle efficiency and performance. Current customer has become aware and sensitive towards vehicle NVH. Hence, OEMs have to cater to this demand through optimized design and layout. In a passenger vehicle, CNG is stored at high pressure and delivered to injectors after pressure reduction at a regulator. During engine idling opening and closing motion of the CNG injector generates back pulsation and these pulsations cause vibrations which may propagate through other components in the delivery path and perceived as noise inside vehicle cabin. To identify the frequencies involved in pressure pulsation, a 1-D simulation of CNG fuel system is performed using GT-Suite through which excitation frequencies and pressure pulsation peak
Meena, Deepesh, Sharma, Rohan, KHANDELWAL, ABHISHEK, Jadhav, Praveen Singh, Pai, Devananda
A study on the effect of an acoustic valve in the exhaust silencer for noise reduction in automotive application2024-26-022001/16/2024
Customer preference towards quieter vehicles is ever-increasing. Exhaust tailpipe noise is one of the major contributors to in-cab noise and pass-by-noise of the vehicle. This research proposes a silencer with an integrated acoustic valve to reduce tailpipe noise, especially in the lower frequency range. Incident exhaust wave coming from the engine strikes the acoustic valve and generates reflected waves. Incident waves and reflected waves cancel out each other which results in energy loss of the exhaust gas. This loss of energy results in reduced noise at the exhaust tailpipe end. To evaluate the effectiveness of the proposed silencer with an acoustic valve, the Noise, vibration, and harshness (NVH) performance of the proposed silencer is compared with the existing silencer which is without an acoustic valve. A compressed natural gas (CNG) Bus powered by a six-in-line cylinder engine is chosen for the NVH trail. After NVH evaluation, it was found that when using the proposed silencer
SINGH, HAR GOVIND, Khandagale, Anup, Choudhari, Yogeshwar, Kalsule, Dhanaji, Petale, Mahendra
Effect of Natural Gas Composition and Rail Pressure on Injector Performance2024-26-007901/16/2024
The demand for Compressed Biogas (CBG) as an alternative fuel to Compressed Natural Gas (CNG) is rapidly increasing due to its renewable nature and environmental benefits. However, CBG has a different gas composition than CNG, which may require hardware changes in fuel system to adapt to these variations while ensuring the same performance. Fuel delivery system of CNG vehicle comprises of fuel storage tank, fuel delivery circuit, pressure regulator, fuel rail and injector. Performance of a fuel injector and pressure regulator are critical factors in the efficient and effective delivery of gaseous fuel to engine. This paper theoretically examines fuel flow requirement of injectors with different gas compositions such as CNG, CBG, G25, G20 and taking in consideration other factors impacting overall performance. This paper defines one of the approaches to accommodate the variation in fuel composition and rail pressure while targeting same engine performance.
Meena, Deepesh, Sharma, Rohan, KHANDELWAL, Abhishek, Jadhav, Praveen Singh, Pai, Devananda
Experimental Analysis of Pressure Pulsation Noise Phenomenon in a CNG-Powered Passenger Vehicle2025-01-011205/05/2023
Compressed Natural Gas (CNG) engine has proved itself to be a worthy replacement for conventional fuels like gasoline & diesel in heavy commercial and passenger transport applications all over the world. Natural gas can be used to reduce carbon dioxide emissions while the global distribution of natural gas allows energy independence for regions with gas rather than oil reserves. In India, infrastructure development of CNG distribution and stringent emission regulations have increased the interest shown by Original Equipment Manufacturers (OEM) to concentrate towards development of CNG vehicles in every segment. From noise & vibration perspective, CNG powered vehicles are expected to maintain the same level of cabin refinement as their fossil fuel equivalents. However, one of the major challenges associated with CNG vehicles is the excitation due to additional components like CNG Pressure Regulator, Injector et al. The operational metallic / pulsation noises are generally higher as
Chatterjee, Joydeep, Ravindran, Mugundaram
Allison's now open for hydrogen testing22TOFHP10_0510/01/2022
With the atomic number 1, hydrogen is the lightest element in the Periodic Table, but it's rapidly becoming a heavyweight for the mobility future. Development of hydrogen fuel cell vehicle (HFCV) and hydrogen-fueled combustion engines for commercial-vehicle use is driving demand for specialized testing and validation facilities. Allison Transmission is in the vanguard of this movement, recently launching a comprehensive hydrogen test capability at its 60,000-ft2 (5,575-m2) Vehicle Electrification + Environmental Test Center in Indianapolis. Prior to its official debut, SAE Media was provided an exclusive look at the new facility - which also includes compressed natural gas (CNG) testing - courtesy of David Proctor, the test center's general manager, and Tim Szilveszter, Allison's sales account manager.
Brooke, Lindsay
The effectiveness of traditional knock mitigation strategies to increase load on a DI H2 engine2022-01-057103/29/2022
One way to reduce a vehicles tailpipe CO2 emissions is to use a fuel with a higher hydrogen to carbon ratio. The use of pure hydrogen result in near-zero tailpipe CO2 emissions. However the use of hydrogen in pre-mixed spark-ignition combustion systems results in abnormal combution event. The fast burn-rate of hydrogen can result in high-frequency pressure oscillations while the low motor octane number (MON) leads to pre-ignition as load increases. End-gas knock is also observed at relatively low loads with pure hydrogen. In this study, lean operation, EGR operation and water injection are used to mitigate some of the combustion challenges associated with pure H2 combustion. Data was collected on a 115 mm bore 1.3 liter single-cylinder research engine operating at 12:1 geometric compression ratio. Hydrogen was injected through a side-mounted direct injector at 100 bar rail pressure. The results are compared to port-fuel injected compressed natural gas.
Conway, Graham
Optimized TWC for emission control on a heavy duty stoichiometric CNG engine2022-01-070603/29/2022
Compressed natural gas (CNG) engines have attracted increasing attention in the heavy duty (HD) vehicle market as an alternative to conventional diesel fuel often due to the abundance and low price of CNG. However, it is challenging to meet the increasingly stringent China VI legislation, particularly for hydrocarbons (mainly CH4), carbon monoxide (CO), nitrogen oxides (NOx) and ammonia (NH3). In this work, approaches were explored in which a gasoline three-way catalyst (TWC) was modified through the optimization of materials and design. The optimized TWC was evaluated in a laboratory reactor and with a HD stoichiometric CNG engine. Lab reactor results showed improve CH4 light off performance. Ammonia (NH3) is a by-product during the operation of three-way catalysts (TWC) on a stoichiometric CNG engine. Catalytic modifications are discussed which were demonstrated to reduce NH3 emissions due to the relatively low NH3 limit for China VI legislation. Data are reported demonstrating the
Qiao, Dongsheng, Wang PhD, Jingwen, Chuma, Hellen, Hu, Hao, Ji, Hongyu, Andersen, Paul, Xu, Shi, Li, Qin
Total Life Cycle Analysis of CNG and Hydrogen Enriched CNG Powered Vehicles : A Comparative Evaluation2021-26-010509/22/2021
Vehicles consume energy and release harmful emissions throughout their life period from the manufacturing stage of raw materials to the vehicle scrapyard. Current Green-House Gas (GHG) emissions with gasoline and diesel vehicles are reported to be 164 gCO2/km and 156 gCO2/km respectively. Thus, enormous researches are carried out for low-carbon alternatives replacing conventional gasoline and diesel vehicles to reduce GHG emissions. The continuous research on hydrogen as a transportation fuel has demonstrated the potential of reduced vehicular emissions compared to conventional fuels. Life cycle assessment (LCA) is a comprehensive technique used to estimate the overall environmental impact of vehicles. In this present work, a comparative LCA is conducted between Compressed Natural gas (CNG) powered vehicles and H-CNG powered vehicles. Also sustainable indicators such as Net Energy Ratio, Fossil Energy Ratio are evaluated for the test cases. The impact of the two alternative vehicles is
N, Vinithkrishna, R, Deepak Narayanan, G N, Ashwin Ram
Development of Dual Fuel (Diesel + CNG) Engine for Off-Road Application2021-26-011909/22/2021
The evolution of engine technology has so far seen the most beneficial side of progress in the fields of transportation, agriculture and mobility. With the advent of innovation, there is also an impact on our environment that needs to be balanced. This is where fuels like CNG, LPG, LNG, etc. outperform the conventional fossil fuels in terms of pollution & operational cost. This paper enlightens on the use of innovative dual fuel technology where diesel & CNG fuels are used for combustion simultaneously inside the combustion chamber. Dual fuel system adaptation for farm application ensures self-reliance of the farmer where he can generate bio-CNG to use the renewable fuel for farming making him less dependent on conventional fossil fuel thus promoting a green economy. The dual fuel system is adapted on the existing in-use diesel engine with minimum modifications. This makes it feasible to retro-fit a CNG fuel system on existing diesel engine so as to operate it on dual fuel mode. Major
Singh, Gagandeep, Dogra, DaljitSingh, Ramana, Ramandeep, Chawla, Jatinder, Sutar, Prasanna S, Sagare, Vinayak Shivalink, Sonawane, Shailesh Balkrishna, Kavathekar, Kishorkumar, Rairikar, Sandeep, Thipse, Sukrut S
Development of an all speed governed Diesel-CNG dual fuel engine for farm Applications2021-26-010109/22/2021
This paper discusses the development of an all speed governed diesel-natural gas dual fuel engine for agricultural farm tractor. A 45 hp, 2.9 liters diesel-natural gas dual fuel engine with a novel closed loop secondary fuel injection system was developed. A frugal approach was followed for conversion, without any modification of the base mechanical diesel fuel injection system. The overall cost impact due to dual fuel conversion was kept minimum, while meeting performance and emissions at par with base diesel operation. Additional cost on gas injection system is redeemed by cost savings on diesel fuel. The dual fuel technology developed by Mahindra & Mahindra Ltd., substitutes on an average approximately 40% of diesel with compressed natural gas, while meeting the mandated agricultural tractor emission norms for dual fuel and meeting all application requirements. The governing performance of the tractor was found to be superior than base diesel tractor. A prototype dual fuel tractor
Raj, Ashwin S, Nagarajan, Vigneshwaran, NISSANGI, JOY KUMAR, Elango, Viknesh, Rajamani, Parthiban, S K, RAVINDRA
Analysis of a gas engine with arbitrary mixture ratio of hydrogen and methane for heavy-duty vehicles2021-01-117709/21/2021
To reduce exhaust emissions in commercial vehicles, hydrogen, as a carbon-free fuel, is a reasonable alternative to conventional fuels. In order to circumvent the current problem of hydrogen availability, the use of a gas engine for heavy duty vehicles(hdv), which is able to operate with pure compressed natural gas (CNG), pure hydrogen as well as any mixture of these both gases, is sensible. For this purpose, an operating concept for a gas engine was developed, which is able to operate with an arbitrary hydrogen-natural gas mixture ratio. For this purpose, the mixture formation of a hydrogen-natural gas-air mixture was analysed in a 3D CFD simulation. The results for pure hydrogen operation show a very good homogenization of the fuel distribution at the point of ignition when an outward-opening injector was used. Based on these results, a 1D simulation was used to generate an operating map of the gas engine and investigate it with regard to its efficiency and exhaust emissions. A lean
Klepatz, Kevin, Tempelhagen, Robin, Rottengruber, Hermann
Analysis on Emission Characteristics of Urban Buses Based on Remote Online Monitoring2021-01-060104/06/2021
In this study, a new system of assessment method was developed to evaluate the characteristics of urban buses based on remote online monitoring. Four types of buses, including China V emission standards diesel bus, lean-burn CNG bus, air-fuel equivalence ratio combustion CNG bus and gas-electric hybrid bus, were chosen as samples to analyze the emission characteristics of urban buses with different engine types in urban scenario. Based on the traffic conditions in Beijing, the actual emission characteristics of buses under newly-built driving conditions were analyzed. Moreover, the emission factor database of urban buses in Beijing was established to analyze the characteristics of excess emission. The research results are shown as follows. 1) Compared with other types of buses, NOX emission factor and emission rate of lean-burn CNG bus are much higher. The equivalent air-fuel ratio CNG engine combined with TWC catalytic converter and hybrid power technology can better reduce NOX
Feng, Qian, Zhen, Kai, Lu, Yang, Yang, Xingzi, Yang, Yanyan, Liu, Baoxian, Li, Mengliang, Li, Zhijun
Toward Predictive Combustion Modeling of CNG SI Engines in 1D Simulation Tools2020-01-207909/15/2020
In the recent years, the interest in heavy-duty engines fueled with Compressed Natural Gas (CNG) is increasing due to the necessity to comply with the stringent CO2 limitation imposed by national and international regulations. Indeed, the reduced number of carbon atoms of the NG molecule allows to reduce the CO2 emissions compared to a conventional fuel. The possibility to produce synthetic methane from renewable energy sources, or bio-methane from agricultural biomass and/or animal waste, contributes to support the switch from conventional fuel to CNG. To drive the engine development and reduce the time-to-market, the employment of numerical analysis is mandatory. This requires a continuous improvement of the simulation models toward real predictive analyses able to reduce the experimental R&D efforts. In this framework, 1D numerical codes are fundamental tools for system design, energy management optimization, and so on. The present work is focused on the improvement of the
Riccardi, Marco, Tufano, Daniela, Beatrice, Carlo, Bozza, Fabio, De Bellis, Vincenzo, Napolitano, Pierpaolo
Particulate Matter (PM) Emissions of Euro 5 and Euro 6 Vehicles Using Systems with Evaporation Tube or Catalytic Stripper and 23 nm or 10 nm Counters2020-01-220309/15/2020
Particle number (PN) emission limits were introduced in the European Union’s regulations for light-duty and heavy duty vehicles in the years 2011-2014. Since then, PN measurements have become a common practice in the automotive sector. Many studies showed that the current methodology, which counts particles >23 nm, misses a large fraction of particles for some engine technologies, such as port fuel injection vehicles or vehicles fueled with compressed natural gas (CNG). However, data for the latest technology vehicles are lacking. For this reason, we measured PN emissions >23 nm and >10 nm of >30 CNG, gasoline and diesel-fueled vehicles. Two systems were measuring in parallel from the full dilution tunnel; one with an evaporation tube and the other with a catalytic stripper. The PN emission levels spanned over three orders of magnitude depending on whether there was a particulate filter installed or not. The differences between the two systems (>23 nm) were on average 6%, indicating
Giechaskiel, Barouch, Woodburn, Joseph, Szczotka, Andrzej, Bielaczyc, Piotr
Experimental and Numerical Characterization of High-Pressure Methane Jets for Direct Injection in Internal Combustion Engines2020-01-212409/15/2020
Compressed Natural Gas (CNG) is regarded as a promising fuel for spark-ignited (SI) internal combustion engines (ICE) to improve engine thermal efficiency and reduce both carbon dioxide and pollutant emissions. Significant advantages of CNG are higher-octane number, higher hydrogen to carbon ratio, and lower energy-specific CO2 emissions compared with gasoline. More, it can be produced in renewable ways, and is more widespread and cheaper than conventional liquid fossil fuels. In this regard, the direct injection of CNG engines can be considered a promising technology for highly efficient and low-emission future engines. This work reports an experimental and numerical characterization of high-pressure methane jets from a multi-hole injector for direct injection engines. The tests were performed in a constant volume (CV) combustion chamber under a broad range of operating conditions in terms of injection pressure, in the range 1.0 - 5.0 MPa, and ambient back-pressure in between 0.05 to
Montanaro, Alessandro, Allocca, Luigi, De Vita, Angelo, Ranieri, Stefano, Duronio, Francesco, Meccariello, Giovanni
Experimental Study on Ignitability of Lean CNG/Air Mixture in the Multi-Stage Cascade Engine Combustion System2020-01-208409/15/2020
Lean air-gas mixture combustion systems seem to be very promising solutions for IC engines in terms of lower emission indexes and higher thermal efficiency, especially in part-load operation. The main problem however is the necessity to provide the bigger activation energy for ignition of lean and very lean mixtures. In several publications and in research performed by the authors of this paper it has been confirmed, that the implementation of turbulent jet ignition (TJI) results in significantly faster inflammation of lean CNG/air mixture due to the improvement in on-ignition mechanism. The TJI-system consists of two chambers connected with nozzles. The orifices generate complex charge movement and decrease significantly the charge homogeneity in the pre-chamber, interrupting therefore first ignition process. The main research question of the investigations reported here was to improve this unfavorable property and to validate better inflammation ability in the pre-chamber by applying
Bueschke, Wojciech, Szwajca, Filip, Wislocki, Krzysztof
Measurement of Fuel Distribution in a Small PFI Spark-Ignition Engine Using Tracer PLIF2020-01-078604/14/2020
The distribution of fuel-air mixture inside the engine cylinder strongly influences the combustion process. Planar laser-induced fluorescence (PLIF) is commonly used for fuel distribution measurement, however, it is mostly reported on moderate- to large-sized engines. In the present work, PLIF is applied to measure the fuel distribution inside the cylinder of a small, four-stroke, port-fuel-injection (PFI), spark-ignition engine with displacement volume of 110 cm3. Iso-octane was used as the base fuel, and 3-pentanone (15% by volume) was added as a fluorescent tracer in the base fuel. The effect of equivalence ratio, considering ϕ = 1.2, 1.0, and 0.8, on in-cylinder fuel distribution was studied with low throttle opening of 25% at 1200 rpm. PLIF images were recorded at different crank angle degrees during both intake and compression strokes over a swirl measurement plane located at the TDC position. It was found that the fuel stratification was present from intake to even late
Garg, Shubham, Mittal, Mayank, Sahu, Srikrishna, Lakshminarasimhan, V
Effects of Piston Bowl Diameter on Combustion Characteristics of a Natural gas/Diesel Dual Fuel Engine2019-01-217312/19/2019
Natural gas/diesel dual fuel engines have potential for a high thermal efficiency and low NOx emissions. However, they have the disadvantages of high unburned species emissions and lower thermal efficiencies at low loads (at low equivalence ratio). A way to solve this problem is to properly distribute the pilot fuel vapor in a natural-gas premixture. The combustion chamber geometry affects the combustion process since it influences the distribution of the pilot fuel vapor. This study investigates the influence of injection conditions and the piston bowl geometry on the performance and emissions of a dual fuel engine. Experiments were carried out using two pistons with different bowl diameters, 52 mm and 58 mm, at single-and two-stage diesel-fuel injection. The results show that the larger bowl provides lower hydrocarbon emissions at a lower equivalence ratio in the case of single-stage injection. For two-stage injection, the influence of the bowl diameter depends on the timing of the
Takizawa, Keigo, Tanaka, Hidetake, Horibe, Naoto, Ishiyama, Takuji, Sako, Takahiro
Effects of Engine Operating Condition and Fuel Property on Pre-Ignition Phenomenon in a Highly Boosted Premixed Natural Gas Engine2019-01-215412/19/2019
The stochastic pre-ignition phenomenon plays a vital role to limit the further increasing BMEP for natural gas engines. In this study, the pre-ignition propensities were examined in a highly boosted premixed natural gas engine by various engine loads and air/fuel ratios, as well as different methane number (MN) altered by hydrogen addition. A proper pre-ignition evaluation method was proposed referring to intake temperature. Moreover, the limits of in-cylinder temperature and pressure for the onset of pre-ignition were estimated. The results show that both higher IMEP and richer mixture conditions readily lead to pre-ignition. The significant increases of pre-ignition frequency and heavy-knocking pre-ignition cycle present with lowering MN.
Chen, Run, Kuboyama, Tatsuya, Moriyoshi, Yasuo, Yasueda, Shinji, Doyen, Valerie, Martin, Jean-Baptiste
1D Numerical and Experimental Investigations of an Ultralean Pre-Chamber Engine03-13-02-001211/19/2019
Abstract In recent years, lean-burn gasoline Spark-Ignition (SI) engines have been a major subject of investigations. With this solution, in fact, it is possible to simultaneously reduce NOx raw emissions and fuel consumption due to decreased heat losses, higher thermodynamic efficiency, and enhanced knock resistance. However, the real applicability of this technique is strongly limited by the increase in cyclic variation and the occurrence of misfire, which are typical for the combustion of homogeneous lean air/fuel mixtures. The employment of a Pre-Chamber (PC), in which the combustion begins before proceeding in the main combustion chamber, has already shown the capability of significantly extending the lean-burn limit. In this work, the potential of an ultralean PC SI engine for a decisive improvement of the thermal efficiency is presented by means of numerical and experimental analyses. The SI engine is experimentally investigated with and without the employment of the PC with the
Bozza, Fabio, De Bellis, Vincenzo, Tufano, Daniela, Malfi, Enrica, Müller, Christoph, Habermann, Knut
MISERLY POWER SYSTEMS19TOFHP10_0210/01/2019
Engineers push engine, transmission technologies to turn off fuel usage. Commercial-truck powertrains are doing more with less. Engine developers are adding features that reduce fuel consumption, saving owners money while helping fleets reduce emissions. Digital technologies continue to transform commercial trucking as powertrain providers devise new ways to eke more from each drop of fuel. Engines now adapt to road conditions, adjusting power and shutting down some or all of the cylinders as demands change. Electric fans and maintenance monitoring now are being used to help keep engines running at maximum efficiency while using less fuel. Design teams also are refining technologies like start-stop and cylinder deactivation, working to make them smooth enough that drivers barely notice the systems are adapting to the environment.
Costlow, Terry
Methane Direct Injection in an Optical SI Engine - Comparison between Different Combustion Modes2019-01-008301/15/2019
Natural gas, biogas, and biomethane are attractive fuels for compressed natural gas (CNG) engines because of their beneficial physical and chemical characteristics. This paper examines three combustion modes - homogeneous stoichiometric, homogeneous lean burn, and stratified combustion - in an optical single cylinder engine with a gas direct injection system operating with an injection pressure of 18 bar. The combustion process in each mode was characterized by indicated parameters, recording combustion images, and analysing combustion chemiluminescence emission spectra. Pure methane, which is the main component of CNG (up to 98%) or biomethane (> 98 %), was used as the fuel. Chemiluminescence emission spectrum analysis showed that OH* and CN* peaks appeared at their characteristic wavelengths in all three combustion modes. The peak of OH* and broadband CO2* intensities were strongly dependent on the air/fuel ratio conditions in the cylinder. Lower OH* and CO2* intensities were
Melaika, Mindaugas, Andersson, Mats, Dahlander, Petter
Durability Improvement of Cylinder Head in Alternate Fuel Engines2018-32-005510/30/2018
Alternate fuels like LPG and CNG are beneficial in terms of operating cost and emissions as well. They also contribute to reduce CO2 emissions. These gas fuels are known for its problems in engines including wear of parts. Cylinder head valve - seat wear is higher in gas engines. This paper discusses the experimental work on reduction of valve -seat wear in 3 wheeler engine. In the development of new higher power version of the gas engine valve-seat interface wear is observed. Effect of this wear on performance, leak and emissions were studied, qualitative measurements of valve temperatures were studied at different conditions with different fuels. Combustion gas and part temperatures are higher in gas engines. Simulation test cycle is developed for the wear test and various solutions to reduce wear at the valve - seat interface were evaluated. Cost effective solution is implemented with minimum changes in engine.
Thiruvallur Loganathan, Balasubramanian, Elumalai, Duraikkannan, Kumaraswamy, Phaneesh, Lakshminarasimhan, V
Improving Combustion and Emission Characteristics in Heavy-Duty Natural-Gas Engine by Using Pistons Enhancing Turbulence2018-01-168509/10/2018
Compressed Natural Gas (CNG), because of its low cost, high H/C ratio, and high octane number, has great potential in automotive industry, especially for heavy-duty commercial vehicles. However, relative slow flame speed of natural gas leads to long combustion duration and low thermal efficiency and tends to cause knock combustion at high load, which will aggravate engine thermal load and reliability. Enhancing turbulence intensity in combustion chamber is an effective way to accelerate flame propagation speed and improve combustion performance. In this study, the flow simulations of several piston bowls with different inner-convex forms were carried out using three-dimensional computational fluid dynamics (3D-CFD) software CONVERGE. The numerical results showed the piston bowls with inner-convex could disturb the charge swirl motion and enhance turbulence of different intensity. A hexagram geometry bowl was proved to have the best function in strengthening turbulence intensity. Hence
Li, Fubai, Liu, Changpeng, Song, Heping, Wang, Zhi
Study of Turbulent Entrainment Quasi-Dimensional Combustion Model for HCNG Engines with Variable Ignition Timings2018-01-168709/10/2018
Presently, urban transportation highly depends on the fossil fuels, but its rapid fluctuating economic issues and environmental consequences impose the variegation of energy sources. Hydrogen enriched compressed natural gas (HCNG) engines offer the potential of higher brake thermal efficiency with low emissions, which also satisfies the strict pollutant emission standards. The two-zone turbulent entrainment quasi-dimensional combustion model is developed to predict the combustion process of spark-ignited hydrogen enriched compressed natural gas-fueled engines. The fundamentals of thermodynamic process, turbulent flame propagation model and other sub-models like laminar burning velocity, adiabatic temperature and ignition lag model are introduced for the better accuracy. The experiments have been conducted for three different fuels; pure CNG, 20% HCNG, and 40% HCNG blends under MAP of 105 kPa for various excess air ratios (λ) and ignition timing (θi). The three calibration coefficient
Mehra, Roopesh Kumar, Ma, Fanhua, Hao, Duan, Juknelevičius, Romualdas
Characterization of Hollow Cone Gas Jets in the Context of Direct Gas Injection in Internal Combustion Engines2018-01-029604/03/2018
Direct injection (DI) compressed natural gas (CNG) engines are emerging as a promising technology for highly efficient and low-emission engines. However, the design of DI systems for compressible gas is challenging due to supersonic flows and the occurrence of shocks. An outwardly opening poppet-type valve design is widely used for DI-CNG. The formation of a hollow cone gas jet resulting from this configuration, its subsequent collapse, and mixing is challenging to characterize using experimental methods. Therefore, numerical simulations can be helpful to understand the process and later to develop models for engine simulations. In this article, the results of high-fidelity large-eddy simulation (LES) of a stand-alone injector are discussed to understand the evolution of the hollow cone gas jet better. The hollow cone gas jet is characterized in terms of several parameters such as axial penetration length, maximum jet width, area of jet, volume of jet, and mixing in terms of the mass
Deshmukh, Abhishek Y., Vishwanathan, Giridar, Bode, Mathis, Pitsch, Heinz, Khosravi, Maziar, Bebber, David van
Carbon Monoxide Emissions Model for Data Analytics in Internal Combustion Engine Applications Derived from Post-Flame Chemical Kinetics2018-01-115304/03/2018
In this work, a new CO emissions formation model is developed based on the dynamics of a representative pool of radicals in the post-flame combustion gases. The ultimate target is the derivation of a kinetics-based CO model, formulated by a single differential equation, that can run very fast in any engine diagnostic/post-processing tool which analyzes in-cylinder processes in the framework of big data acquired at the engine test bench or during engine operation in the field. Specific objectives in the development of the current model are (i) inclusion of the effect of engine operating conditions on the CO emissions formation mechanism, (ii) ease of implementation in any diagnostic code/platform, (iii) fast running times toward real-time capability, and (iv) robustness. The presently developed CO model consists of a single Ordinary Differential Equation (ODE) that can be solved analytically, without the need of a stiff chemical kinetics solver. A characteristic parameter, which can be
Bikas, Georgios, Michos, Konstantinos
Numerical Investigation of Direct Gas Injection in an Optical Internal Combustion Engine2018-01-017104/03/2018
Direct injection (DI) of compressed natural gas (CNG) is a promising technology to increase the indicated thermal efficiency of internal combustion engines (ICE) while reducing exhaust emissions and using a relatively low-cost fuel. However, design and analysis of DI-CNG engines are challenging because supersonic gas jet emerging from the DI injector results in a very complex in-cylinder flow field containing shocks and discontinuities affecting the fuel-air mixing. In this article, numerical simulations are used supported by validation to investigate the direct gas injection and its influence on the flow field and mixing in an optically accessible ICE. The simulation approach involves computation of the in-nozzle flow with highly accurate Large-Eddy Simulations, which are then used to obtain a mapped boundary condition. The boundary condition is applied in Unsteady Reynolds Averaged Navier-Stokes simulations of the engine to investigate the in-cylinder velocity and mixing fields. The
Deshmukh, Abhishek Y., Falkenstein, Tobias, Pitsch, Heinz, Khosravi, Maziar, Bebber, David van, Klaas, Michael, Schroeder, Wolfgang
Solid Particle Number and Ash Emissions from Heavy-Duty Natural Gas and Diesel w/SCRF Engines2018-01-036204/03/2018
Solid and metallic ash particle number (PN) and particulate matter (PM) mass emission measurements were performed on a heavy-duty (HD) on-highway diesel engine and a compressed natural gas (CNG) engine. Measurements were conducted under transient engine operation that included the FTP, WHTC and RMC. Both engines were calibrated to meet CARB ultra low NOX emission target of 0.02 g/hp-hr, a 90% reduction from current emissions limit. The HD diesel engine final exhaust configuration included a number of aftertreatement sub-systems in addition to a selective catalytic reduction filter (SCRF). The stoichiometric CNG engine final configuration included a closed coupled Three Way Catalyst (ccTWC) and an under floor TWC (ufTWC). The aftertreatment systems for both engines were aged for a full useful life (FUL) of 435,000 miles, prior to emissions testing. PM mass emissions from both engines were comparable and well below the US EPA emissions standard. However, the CNG engine emitted a
Khalek, Imad A., Badshah, Huzeifa, Premnath, Vinay, Brezny, Rasto
An Analysis of Dual-Fuel Combustion of Diesel with Compressed Natural Gas in a Single-Cylinder Engine2018-01-024804/03/2018
The recent increase in natural gas availability has made compressed natural gas (CNG) an option for fueling the transportation sector of the United States economy. In particular, CNG is advantageous in dual-fuel operation alongside ultra low sulfur diesel (ULSD) for compression ignition (CI) engines. This work investigates the usage of natural gas mixtures at varying Energy Substitution Rates (ESRs) within a high compression ratio single-cylinder CI engine, including performance and heat release modeling of dual-fuel combustion. Results demonstrate the differing behavior of utilizing CNG at various substitution rates. In particular, low ESRs (0-18%) find that operation is not too dissimilar from that of neat ULSD, moderate ESRs (40-60%) show that combustion begins to change but significant modifications to engine operation (i.e., ULSD injection timing) are not required, and high ESRs (75-85%) demonstrate relatively large changes to ULSD injection behavior in order to achieve optimized
Mattson, Jonathan M. S., Langness, Chenaniah, Depcik, Christopher
Comparison of Engine Operational Modes with Respect to Compression Ignition Engine Knock2018-01-021904/03/2018
Diesel knock and ringing combustion in compression ignition (CI) engines are largely an unavoidable phenomenon and are partially related to the overall effectiveness of the fuel injection process. Modern electronic fuel injection systems have been effective at reducing the intensity of knock in CI engines, largely through optimization of fuel injection timing, as well as higher operating pressures that promote enhanced fuel and air mixing. In this effort, a single-cylinder CI engine was tested under a number of different combustion strategies, including a comparison of mechanical and electronic injection systems, increasing fuel injection pressures for biodiesel fuels, and the usage of dual-fuel combustion with compressed natural gas (CNG). Using in-cylinder pressure traces and engine operational data, the difference in injection mechanisms, fuel preparation, and their effects on knock intensity is clearly illustrated. This allows a means of comparison across multiple engine combustion
Mattson, Jonathan M. S., Depcik, Christopher
Recommended Practices for CNG Powered Medium and Heavy-Duty TrucksJ2406_201802 (Current)02/12/2018
This SAE Recommended Practice provides guidance for the construction, operation, and maintenance of CNG powered medium and heavy-duty trucks. The intent of this document is to cover TRUCKS (6350 kg (14 001 gvw pounds) and above) and specifically excludes passenger vehicles such as: buses, recreational vehicles, motor homes and/or passenger vehicles which may incorporate a truck chassis in their construction.
Truck and Bus Powertrain Committee
Liquefied Natural Gas (LNG) Vehicle Metering and Dispensing Systems - Truck and BusJ2645_201802 (Current)02/12/2018
This SAE Recommended Practice applies to Liquefied Natural Gas Vehicle Fuel. The purpose of this document is to provide information on issues that are important to consider regarding LNG metering and dispensing systems.
Truck and Bus Powertrain Committee
Real World Fleet Test to Determine the Impact of Lower Viscosity Engine Oils from Heavy-Duty CNG and Diesel Buses. Part II: Oil Performance2017-01-235110/08/2017
Low viscosity engine oils are considered a feasible solution for improving fuel economy in internal combustion engines (ICE). So, the aim of this study was to verify experimentally the performance of low viscosity engine oils regarding their degradation process and possible related engine wear, since the use of low viscosity engine oils could imply higher degradation rates and/or unwanted wear performance. Potential higher wear could result in a reduction in life cycle for the ICE, and higher degradation rates would be translated in a reduction of the oil drain period, both of them non-desired effects. In addition, currently limited data are available regarding “real-world” performance of low viscosity engine oils in a real service fleet. In this particular case, there were included out-of-the European Automobile Manufacturers' Association (ACEA) oil specifications in terms of HTHS dynamic viscosity, where low viscosity was considered (3.0 mPa·s), making this test highly interesting
Tormos, Bernardo, Miró, Guillermo, Ramirez, Leonardo, Pérez, Tomás
Development of CNG/Diesel Dual-Compatible Engine Oil for Heavy-Duty Trucks in Thailand2017-01-235010/08/2017
In Thailand, most heavy-duty trucks were equipped with diesel engine, while a small portion was equipped with compressed natural gas (CNG) engine. However, in the past few years the number of CNG fuel trucks in Thailand has increased significantly due to the cheaper cost of CNG. In general, the emphasis of heavy-duty diesel engine oil performance is on piston cleanliness and soot handling properties, while thermal and anti-oxidation properties are most critical for CNG engine oil performance. For truck fleet owners who operate both types of trucks, using the inappropriate oil that is not fit-for-purpose can adversely affect engine performance and reduce engine service lifespan under prolonged usage. A novel CNG/diesel engine oil was developed to meet both JASO DH-2 heavy-duty diesel engine oil performance and CNG engine oil performance. The candidate formulation was proved adequately fit for practical use regarding to thermal and anti-oxidation properties. Engine durability tests were
Wongtaewan, Chalermwut, Wongjareonpanit, Umaporn, Sivara, Komkrit, Hashimoto, Ken, Nakamura, Yoichiro
Real World Fleet Test to Determine the Impact of Low Viscosity Engine Oils from Heavy-Duty CNG and Diesel Buses - Part I: Fuel Consumption2017-01-235310/08/2017
One of the most interesting alternatives to reduce friction losses in the internal combustion engines is the use of low viscosity engine oils. Recently, a new engine oil category focused fuel economy, has been released in North America encouraging the use of these oils in the heavy-duty vehicles’ segment. This paper presents the results of a comparative test where the differences in fuel consumption given by the use of these oils are shown. The test included 48 buses of the urban public fleet of the city of Valencia, Spain. The selected vehicles were of four different bus models, three of them fueled with diesel and the other one with compressed natural gas (CNG). Buses’ fuel consumption was calculated on a daily basis from refueling and GPS mileage. After three oil drain intervals (ODI), the buses using low viscosity engine oils presented a noticeable fuel consumption reduction. These results bear out the suitability of these oils to palliate engine inefficiencies.
Tormos, Bernardo, Ramirez, Leonardo, Miró, Guillermo, Pérez, Tomás
Port Fuel Injection of CNG for Downsized 1-Liter 3-Cylinder Turbocharged Engine with High Efficiency2017-01-227510/08/2017
In order to meet increasingly stringent emission regulations and reduce fuel consumption, development of modern powertrain is becoming more complicated, combining many advanced technologies. Gasoline engine downsizing is already established as a proven technology to reduce vehicle fleet CO2 emissions. Compressed natural gas (CNG) offers increased potential to further reduce both tailpipe CO2 and other regulated exhaust gas emissions without compromising driving performance. In this study, a turbocharged CNG port fuel injection (PFI) engine was developed based on gasoline version. Making most use of positive fuel properties of CNG, the paper quantifies the performance characteristics of downsized CNG engine considering reduced knock sensitivity, adaption of compression ratio and combustion efficiency. While peak cylinder pressure was controlled below 120 bar, peak torque 180Nm, same level as gasoline variant, was realized from 3000rpm. The results achieved from the test engine whilst
Yang, Chen, li, Weixin, Yin, Jiandong, Shen, Yuan
Influence of Binary CNG Substitute Composition on the Prediction of Burn Rate, Engine Knock and Cycle-to-Cycle Variations2017-01-051803/28/2017
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
An Optical Investigation of Multiple Diesel Injections in CNG/Diesel Dual-Fuel Combustion in a Light Duty Optical Diesel Engine2017-01-075503/28/2017
Dual-fuel combustion combining a premixed charge of compressed natural gas (CNG) and a pilot injection of diesel fuel offer the potential to reduce diesel fuel consumption and drastically reduce soot emissions. In this study, dual-fuel combustion using methane ignited with a pilot injection of No. 2 diesel fuel, was studied in a single cylinder diesel engine with optical access. Experiments were performed at a CNG substitution rate of 70% CNG (based on energy) over a wide range of equivalence ratios of the premixed charge, as well as different diesel injection strategies (single and double injection). A color high-speed camera was used in order to identify and distinguish between lean-premixed methane combustion and diffusion combustion in dual-fuel combustion. The effect of multiple diesel injections is also investigated optically as a means to enhance flame propagation towards the center of the combustion chamber. These effects are studied optically through use of temporally resolved
Nithyanandan, Karthik, Gao, Yongli, Wu, Han, Lee, Chia-Fon, Liu, Fushui, Yan, Junhao
Evaluating Different Measures to Improve the Numerical Simulation of the Mixture Formation in a Spark-Ignition CNG-DI-Engine2017-01-056703/28/2017
Compressed Natural Gas (CNG) is a promising alternative fuel for internal combustion engines as its combustion is fuel-efficient and lean in carbon dioxide compared to gasoline. The high octane number of methane gives rise to significant increase of the thermodynamic efficiency due to higher possible compression ratios. In order to use this potential, new stratified mixture formation concepts for CNG are investigated by means of numerical fluid simulations. For decades RANS methods have been the industry standard to model three-dimensional flows. Indeed, there are well-known deficiencies of the widely used eddy viscosity turbulence models based on the applied Boussinesq hypothesis. Reynolds stress turbulence models as well as scale resolving simulation approaches can be appealing alternative choices since they offer higher accuracy. However, due to their large computing effort, they are still mostly impractical for the daily use in industrial product development processes. A more
Twellmeyer, Andrea, Kopple, Fabian, Weigand, Bernhard
Recommended Practice for Compressed Natural Gas Vehicle FuelJ1616_201703 (Current)03/06/2017
Compressed Natural Gas (CNG) is a practical automotive fuel, with advantages and disadvantages when compared to gasoline. Large quantities of natural gas are available in North America. It has a higher octane number rating, produces low exhaust emissions, no evaporative emissions and can cost less on an equivalent energy basis than other fuels. Natural gas is normally compressed from 20 684 to 24 821 kPa (3000 to 3600 psig) to increase its energy density thereby reducing its on-board vehicle storage volume for a given range and payload. CNG can also be made from liquefied natural gas by elevating its pressure and vaporizing it to a gas. Once converted it is referred to LCNG. The properties of natural gas are influenced by: (1) source of supply i.e. field, composition or impurities; (2) the processing of natural gas by the production and transmission companies; (3) the regional gas supply, storage, and demand balancing done by distribution companies often in concert with pipeline
Fuels and Lubricants TC 7 Fuels Committee
Fuel Tank for Liquefied Natural GasTBMG-2616001/01/2017
NASA’s Marshall Space Flight Center has developed a new composite vessel technology that is suitable for use as a liquefied natural gas (LNG) fuel storage tank for alternative fuel vehicles. This technology uses an improved composite over-wrapped technology to produce a pressure vessel that is simple to use, robust, and capable of withstanding high pressures. It is also lightweight and low cost. This technology shows great potential to help the United States and other countries move toward a cleaner environment while allowing for efficient use of a more natural fuel in many different applications.
Composite Pressure Vessel Including Crack Arresting BarrierTBMG-2601712/01/2016
NASA’s Marshall Space Flight Center innovators have developed several new designs and methods of fabrication for composite and composite-overwrapped tank vessels that help significantly improve their structural integrity against impact, abrasion, harsh environments, and fire. Several embodiments of this technology portfolio also enable production of composite tanks capable of transporting liquefied natural gas or other cryogenic liquids. These innovations are applicable to important aerospace needs, including propulsion systems, as well as new and growing fields such as natural gas transportation.
Heavily Downsized Demonstrator Engine Optimised for CNG Operation2016-01-236310/17/2016
The complexity of modern powertrain development is demonstrated by the combination of requirements to meet future emission regulations and test procedures such as Real Driving Emissions (RDE), reduction of fuel consumption and CO2 emissions as well as customer expectations for good driving performance. Gasoline engine downsizing is already established as a proven technology to reduce automotive fleet CO2 emissions. Additionally, alternative fuels such as natural gas, offer the potential to significantly reduce both tailpipe CO2 and other regulated exhaust gas emissions without compromising driving performance and driving range. This paper presents results showing how the positive fuel properties of natural gas can be fully utilised in a heavily downsized engine. The engine has been modified to cope with the significantly higher mechanical and thermal loads when operating at high specific outputs on compressed natural gas (CNG). In this study, peak cylinder pressures of up to 180 bar
Hall, Jonathan, Bassett, Mike, Hibberd, Benjamin, Streng, Simon
Hydrocarbon Speciation in Blended Gasoline-Natural Gas Operation on a Spark-Ignition Engine2016-01-216910/17/2016
The high octane rating and more plentiful domestic supply of natural gas make it an excellent alternative to gasoline. Recent studies have shown that using natural gas in dual fuel engines provides one possible strategy for leveraging the advantages of both natural gas and gasoline. In particular, such engines been able to improve overall engine efficiencies and load capacity when they leverage direct injection of the natural gas fuel. While the benefits of these engine concepts are still being explored, differences in fuel composition, combustion process and in-cylinder mixing could lead to dramatically different emissions which can substantially impact the effectiveness of the engine’s exhaust aftertreatment system. In order to explore this topic, this study examined the variations in speciated hydrocarbon emissions which occur for different fuel blends of E10 and compressed natural gas and for different fuel injection strategies on a spark-ignition engine. Results indicate that
Hall, Carrie M., Sevik, James, Pamminger, Michael, Wallner, Thomas
Analysis of a Dual-Fuel Combustion Engine Fueled with Diesel Fuel and CNG in Transient Operating Conditions2016-01-230510/17/2016
The paper presents the thermodynamic analysis of the engine supplied with small and large diesel fuel doses while increasing natural gas quantity. The paper presents changes in the combustion process thermodynamic indexes and changes in the exhaust gas emissions for dynamically increased share of the gaseous fuel. The cylinder pressure history was subject to thermodynamic analysis, . based on which the mean indicated pressure, the heat release rate, the quantity of heat released as well as the pressure rate increase after self-ignition were determined. These parameters were also referred to the subsequent engine operation cycles by specifying the scope of the change per cycle. The relationship between the engine load and the start, the center and the end of combustion while increasing the gas amount supplied to the cylinder was indicated. The presented analysis of the results indicates significant impact of the changes in the supplied gas amount on the engine operating indexes and
Pielecha, Ireneusz, Wislocki, Krzysztof, Cieslik, Wojciech, Borowski, Przemyslaw, Bueschke, Wojciech, Skowron, Maciej
Standard for Compressed Natural Gas Vehicle FuelJ1616_201605 (Historical)05/12/2016
Compressed Natural Gas (CNG) is a practical automotive fuel, with advantages and disadvantages when compared to gasoline. Large quantities of natural gas are available in North America. It has a higher octane number rating, produces low exhaust emissions, no evaporative emissions and can cost less on an equivalent energy basis than other fuels. Natural gas is normally compressed from 20 684 to 24 821 kPa (3000 to 3600 psig) to increase its energy density thereby reducing its on-board vehicle storage volume for a given range and payload. CNG can also be made from liquefied natural gas by elevating its pressure and vaporizing it to a gas. Once converted it is referred to LCNG. The properties of natural gas are influenced by: (1) source of supply i.e. field, composition or impurities; (2) the processing of natural gas by the production and transmission companies; (3) the regional gas supply, storage, and demand balancing done by distribution companies often in concert with pipeline
Fuels and Lubricants TC 7 Fuels Committee
GASTONE: New Powertrain Concept for CNG Engines2016-01-063104/05/2016
The present concern in the reduction of CO2 emissions occasioned by heavy duty trucks is leading to a technological evolution, among others, in powertrain electrification. Towards this objective, the EU has funded the project GASTone targeting the development of a new powertrain concept based on the energy recovery from the exhaust gases and kinetic losses in order to make possible the electrification of the main auxiliaries. This new concept will follow a cascade approach in which the exhaust gases energy will be recovered by the integration of an advanced thermoelectric generator followed by a turbo-generator. This system will be combined with a smart kinetic energy recovery device which will recover the energy losses in the deceleration periods of the vehicle. The recovered energy will be used in the electrified auxiliaries. The average performance in a Natural Gas Engine under constant conditions is about 38% (fuel efficiency); with this new concept is expected to rise it by 4
Navarro-Peris, Emilio, Hervas-Blasco, Estefanía, Corberan, José M., Rinaldi, Alex
Comparison of Hydrocarbon Measurement with FTIR and FID in a Dual Fuel Locomotive Engine2016-01-097804/05/2016
Exhaust emissions of non-methane hydrocarbon (NMHC) and methane were measured from a Tier 3 dual-fuel demonstration locomotive running diesel-natural gas blend. Measurements were performed with the typical flame ionization detector (FID) method in accordance with EPA CFR Title 40 Part 1065 and with an alternative Fourier-Transform Infrared (FTIR) Spectroscopy method. Measurements were performed with and without oxidation catalyst exhaust aftertreatment. FTIR may have potential for improved accuracy over the FID when NMHC is dominated by light hydrocarbons. In the dual fuel tests, the FTIR measurement was 1-4% higher than the FID measurement of. NMHC results between the two methods differed considerably, in some cases reporting concentrations as much as four times those of the FID. However, in comparing these data it is important to note that the FTIR method has several advantages over the FID method, so the differences do not necessarily represent error in the FTIR. Specifically, the
Wright, Nolan, Osborne, Dustin, Music, Nathan
Ride Comfort Performance Investigation for Compressed Natural Gas Fuelled Car2015-01-061104/14/2015
This paper presents experimental and theoretical investigations for ride comfort performance of compressed natural gas fuelled car. A compressed natural gas and gasoline fuel are used to run the engine car and its effect on the vehicle ride comfort is evaluated. The ride comfort performance in terms of experimental Root Mean Square (RMS) values of the vertical acceleration at near driver's feet on the floor, on the front and back seat for the same passenger car fuelled by gasoline and natural gas is evaluated. Furthermore, seven degrees of freedom vehicle mathematical model is developed, and validated through laboratory tests. The validation process is performed by comparing the predicted RMS values of the vertical accelerations with the measured RMS values. Furthermore, the optimum values of vehicle suspension parameters are obtained through the validated vehicle model. The experimental results showed that the car fuelled by compressed natural gas gives a significant improvement in
Soliman, Aref M. A., Kaldas, Mina M.S.
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