Browse Topic: Combustion and combustion processes

Items (9,706)

3D-CFD Simulations of H2 ICEs: A Preliminary Evaluation of a Laminar Flame Speed Correction for Thermo-Diffusive Instability

2024-32-007404/18/2025

In recent years, climate change and geopolitical instability have intensified the focus on sustainable power generation. This shift seeks alternatives that balance environmental impact, cost-effectiveness, and practicality. Specifically, in transportation and power generation, electric motors face challenges against internal combustion engines due to the high cost and mass of batteries required for energy storage. This makes electric solutions less favorable for these sectors. Conversely, internal combustion engines, when properly fueled, offer cost-effectiveness and a quasi-environmentally-neutral option. To address these challenges, researchers have explored e-fuels derived from renewable sources as a carbon-neutral supply for internal combustion engines. Among these, hydrogen is particularly promising. In hydrogen-powered internal combustion engines, 3D-CFD (Computational Fluid Dynamics) in-cylinder models are crucial. Once validated, these models can speed up the design process. A

Sfriso, Stefano, Berni, Fabio, Breda, Sebastiano, Fontanesi, Stefano, Cordisco, Ilario, Leite, Caio Ramalho, Brequigny, Pierre, Foucher, Fabrice

Fuel Film Measurement in a SI Gasoline Engine Using a Newly Developed MEMS Sensor

2024-32-007104/18/2025

The previously developed capacitance sensor for detecting a liquid fuel film was modified to apply to the in-cylinder measurement. On the developed sensor surface, comb-shaped electrodes were circularly aligned. The capacitance between the electrodes varies with the liquid fuel film adhering. The capacitance variation between the electrodes on the sensor surface was converted to the frequency variation of the oscillation circuit. In the previous study, it was revealed that the frequency of the oscillation circuit varies with the variation of the liquid fuel coverage area on the sensor surface. The developed sensor was installed in the combustion chamber of the rapid compression and expansion machine, and the performance of the developed sensor was examined. Iso-octane was used as a test fuel to explore the sensor that had been developed. As a result, the adherence of the liquid fuel directly injected into the cylinder was successfully detected under the quiescent and motoring

Kuboyama, Tatsuya, Moriyoshi, Yasuo, Takayama, Satoshi, Nakabeppu, Osamu

Study on the Optimal Pre-Chamber Geometry for Active Pre-Chamber Gas Engines

2024-32-002304/18/2025

In a pre-chamber engine, fuel in the main-chamber is ignited and combusted by the combustion gas injected from the pre-chamber. Therefore, further fuel dilution is possible and thermal efficiency can be also improved. However, adding a pre-chamber to an engine increases the number of design parameters which have a significant impact on the main combustion and the exhaust gas. Then, in this study, the optimum geometry of the pre-chamber in an active pre-chamber gas engine was investigated. The considered parameters were the volume of pre-chamber, the diameter of a nozzle hole, and the number of nozzle holes. 18 types of pre-chambers with different geometries were prepared. Using these pre-chambers, engine experiments under steady conditions were conducted while changing the conditions such as engine speeds, mean indicated pressure and air excess ratio. Based on the experimental data, neural network models were constructed that predict thermal efficiency, NOx and CO emissions from the

Yasuda, Kotaro, Yamasaki, Yudai, Sako, Takahiro, Takashima, Yoshitane, Suzuki, Kenta

Detailed Approach for Pre-Chamber Heat Release Analysis for the HSASI Pre-Chamber Spark Plug Using a Pressure Sensor Glow Plug

2024-32-006304/18/2025

The hot surface-assisted spark ignition (HSASI) pre-chamber spark plug, which was developed at the Karlsruhe University of Applied Sciences, increases the dilution limit with excess air and the tolerance to residual gas in the pre-chamber compared to a conventional passive pre-chamber spark plug. In this study, the conventional glow plug which is integrated in the pre-chamber of the HSASI pre-chamber spark plug was replaced by a pressure sensor glow plug (PSG) from BERU. This allows for a detailed combustion analysis in the pre-chamber. The signal of the PSG was validated with a piezoelectric cylinder pressure sensor and a method to analyse the pre-chamber heat release was introduced. Experimental investigations were carried out on a single-cylinder gasoline engine. A series of operating points diluted with excess air and a variation in load were conducted. The gas flow rate through the orifices of the pre-chamber was calculated from the pressure difference between the pre-chamber and

Holzberger, Sascha, Kettner, Maurice, Kirchberger, Roland

Statistical Analysis of Data Acquired from Propagating Flames in Gasoline Engines Using a Multiple Ion Probe

2024-32-003504/18/2025

Multiple-ion-probe method consists of multiple ion probes placed on the combustion chamber wall, where each individual ion probe detects flame contact and records the time of contact. From the recorded data, it is also possible to indirectly visualize the inside of the combustion chamber, for example, as a motion animation of moving flame front. In this study, a thirty-two ion probes were used to record flames propagating in a two-stroke gasoline engine. The experiment recorded the combustion state in the engine for about 3 seconds under full load at about 6500 rpm, and about 300 cycles were recorded in one experiment. Twelve experiments were conducted under the same experimental conditions, and a total of 4,164 cycles of signal data were obtained in the twelve experiments. Two types of analysis were performed on this data: statistical analysis and machine learning analysis using a linear regression model. Statistical analysis calculated the average flame detection time and standard

Yatsufusa, Tomoaki, Okahira, Takehiro, Nagashige, Kohei

Experimental Investigation of n-C7H16/Ethanol Blended Fuels on Auto-ignition and Flame Propagation in High Temperature/Pressure Constant-Volume Combustion Vessel

2024-32-005004/18/2025

This study aims to investigate the effect of ethanol blends on flame propagation and auto-ignition under high pressure and high temperature conditions. Experimental investigations are conducted using n-C7H16 / ethanol blends at various blending ratios (0, 5, 10, 20, 40, 70, and 100 vol%). The blends are premixed with air at stoichiometric ratios and ignited centrally in a cylindrical constant-volume combustion chamber (20-mm inner diameter, 80-mm long) under elevated temperature (500 K) and pressure (1.0 MPa) conditions. The results show that auto-ignition occurs at an ethanol blend ratio of 10% or less and ceases above 20%. Increasing the ethanol blend to 70% results in a slight change in flame propagation speed, with a noticeable delay at 100%. The pressure measurements show a peak of about 5.6 MPa at a blend ratio of 5%, which gradually decreases with increasing ratios. High-pass filtering reveals the maximum pressure fluctuation amplitude at the 5% blend ratio, indicating increased

Tateishi, Tokua, Yamaguchi, Riki, Shimokuri, Daisuke, Terashima, Hiroshi, Hara, Takaya, Honda, Yuya, Kawano, Michiharu

Enhancing Low Temperature Lean Combustion of CH4-H2 Blends through a Prechamber Equipped Engine

2024-32-004404/18/2025

The use of hydrogen as a sustainable fuel in the short term is hampered by the impossibility of large scale use due low availability. In order to promote decarbonization, complementary solution for a smooth transition is to dilute it in a mixture with methane, in a current Port Fuel Injection (PFI) internal combustion engine (ICE). This can be done as a retrofit after limited structural modifications, such as the introduction of a passive prechamber. Such a solution allows a reduction of the carbon footprint of traditional ICEs through more efficient combustion (both the prechamber technology and the hydrogen fuel properties promote an increase in combustion speed) and a reduced carbon content in the fuel. The present research activity has been carried out through numerical investigation based on three-dimensional CFD analyses to simulate the behavior of a natural gas engine fueled with CH4-H2 blends. The combustion mechanism for the fuel blend was validated against measurements of the

Balduzzi, Francesco, Ferrara, Giovanni, Di Iorio, Silvana, Sementa, Paolo

Effect of Ignition Position on Lean Limit of Main Chamber Combustion in Pre-Chamber Ignition

2024-32-002204/18/2025

An engine was built in this study that enabled the conditions in a pre-chamber and in the main combustion chamber to be visualized simultaneously for the purpose of elucidating the mechanism of pre-chamber combustion. An investigation was made of how the state of pre-chamber combustion, including the location of initial flame generation and its subsequent propagation, influenced pre-chamber jet combustion. The state of pre-chamber combustion was intentionally varied by changing the position of pre-chamber ignition. As a result, it was found that changing the position of pre-chamber ignition varied the location where the pre-chamber flame occurred, how the flame propagated and the timing and strength of the flame jet that was ejected into the main chamber. The results revealed that these differences in the state of pre-chamber combustion markedly changed the rate of combustion fluctuation, combustion period, lean-burn limit and other combustion characteristics depending on the ignition

Onuma, Takeru, Yamada, Hiroto, Ugajin, Taisei, Shinozaki, Kaito, Tahara, Ryota, Iijima, Akira

Studying the Lean Burn Operation in Two-Wheelers to Increase Fuel Efficiency and Investigate the Use of Lean NOx Trap Catalyst (LNT) for Lean Burn System

2024-32-005804/18/2025

This study offers an overview of the impact of lean burn technology in two-wheeler vehicles, specifically concentrating on enhancing the fuel economy and addressing the challenges associated with its adoption. Lean burn systems, characterized by a fuel-air mixture with a higher air content than stoichiometric ratio. The study focuses on technology which meets stringent emission standards while enabling the optimization of fuel efficiency. The lean burn system employs strategies to optimize air-fuel ratio using electronic fuel injection, ignition timing control, and advanced engine control algorithms like - updated torque modulation control algorithm for drivability, lambda control algorithm for rich and lean switch and NOx modelling algorithm for LNT catalyst efficiency tracking. The challenges related to lean burn systems, includes issues related to combustion stability, nitrogen oxide (NOx) emissions, and their impact on drivability, is summarized in the study. Mitigation strategies

Somasundaram, Karthikeyan, Sivaji, Purushothaman, John Derin, C, Vishal, Karwa, Manoj Kumar, S, Maynal, Rajesh

Basic Investigation of Thermodynamic Effects on a Hydrogen Two-Stroke Engine

2024-32-003904/18/2025

The spark ignited two-stroke engine, as a cost-efficient power unit with low maintenance demand, is used millionfold for the propulsion of hand-held application, motorcycles, scooters, boats and others. The outstanding power to weight ratio is the key advantage for two-stroke engines. However, poor exhaust emissions, caused by high scavenge losses, especially on port controlled two-stroke engines, and a low efficiency are disadvantages of this combustion process. Under the aspect of increasing environment- and health awareness, the two-stroke technology driven with fossil resources, shows no future advantage. The anthropogenic climate change force for sustainable development of combustion engines whereby reduction of fuel consumption or usage of alternative fuels is an important factor. Best way of a decarbonization to fulfil future climate goals is the utilization of non-carbon fuels. In this field of fuels, hydrogen, with its high energy content and close inexhaustible availability

Yasuda, Terutaka, Oswald, Roland, Kirchberger, Roland

Experimental Investigations of a Hydrogen Fueled Natural Gas Engine and Ion Current Measurement for Combustion Diagnostics in Pure Hydrogen Operationwith Water Injection

2024-32-006504/18/2025

In the ongoing effort to decarbonize energy supply, a notable shift involves the conversion or retrofitting of combined heat and power plants to operate on hydrogen as an alternative to natural gas. In this transformative landscape, extensive research is underway to develop and explore innovative combustion processes for hydrogen-fueled engines, aiming to comprehend and optimize combustion processes concerning both engine performance and emissions. Among the various methods available for monitoring the combustion process and engine control, ion current sensing presents itself as a viable option. A unique feature of this research lies in utilizing the engine's spark plug itself as an electrical sensor, measuring the ion current generated during the flame development and combustion processes. Given the limited research on ion current sensing for hydrogen combustion processes, a series of experiments were conducted and presented in this work. These experiments involved sweeps of water-to

Salim, Naqib, Beltaifa, Youssef, Kettner, Maurice, Loose, Oliver, Weißgerber, Tycho

Investigation on the Applicability of Passive Type Pre-Chamber with One Port Fuel Injection System to Small Gasoline Engines

2024-32-003304/18/2025

Pre-chamber combustion has been applied as a method of low fuel consumption in spark ignition engines, and in recent years the application of pre-chambers to gasoline engines has also been actively studied. In many gasoline engines, stoichiometric combustion is common. We decided that a passive type pre-chamber with only one port fuel injection is sufficient for stoichiometric combustion. The pre-chamber system relatively has two merits of lower cost and ease of installing than other prechamber systems. Therefore, we focused on investigating the effects of improving combustion speed and knock resistance in use of the passive type pre-chamber and the applicability of the pre-chamber system in various operating points. As the concrete approach, we evaluated the heat balance and the knock resistance with and without a pre-chamber in engine bench test. As a result, the knock resistance and the fuel consumption were improved. In addition, as a result of considering lean burn in the passive

Nakao, Yoshinori, Sakurai, Yota, Hisano, Atsushi, Saitou, Masahito, Suzuki, Tomoharu

Enhancements in Hydrogen Low Pressure Injection on Small Two-Stroke Engines

2024-32-004704/18/2025

The use of small 2-stroke crankcase scavenged engines running on hydrogen is very attractive for low power rates, when low cost and compact dimensions are the fundamental design constraints. However, achieving optimal performance with hydrogen fuel presents challenges, including uneven air-fuel mixtures, fuel losses, and crankcase backfiring. This research focuses on a small 50cc 2-stroke loop-scavenged engine equipped with a patented Low-Pressure Direct Injection (LPDI) system, modified for hydrogen use. Experimental results demonstrate performance comparable to the gasoline counterpart, but further optimizations are needed. Consequently, CFD-3D simulations are employed to analyses the injection process and guide engine development. The numerical analysis focuses on a fixed operating condition: 6000 rpm, Wide Open Throttle (WOT), with a slightly lean mixture and injection pressure fixed at 5 bar. A numerical model of the entire engine is set up with the primary objective of improving

Caprioli, Stefano, Schoegl, Oliver, Oswald, Roland, Kirchberger, Roland, Mattarelli, Enrico, Rinaldini, Carlo Alberto

Optimization of the Numerical Spray Modeling for Polyoxymethylene Dimethyl Ethers for Combustion Prediction in CONVERGE

2025-01-502604/03/2025

Different approaches are undertaken to mitigate the impact of the transport sector on climate change. Alongside electrifying powertrains, sustainable e-fuels such as polyoxymethylene dimethyl ethers (OME) are considered a promising bridging technology for different applications. However, this requires that the engines are optimized for the new fuels. Accordingly, this study aims to optimize the numerical spray modeling of OME in CONVERGE. Based on the KH–RT break-up model, the spray simulations of three different commercial injectors for heavy-duty applications are analyzed regarding the predictability of the liquid and gaseous penetration lengths and the total simulation time. A sensitivity analysis is conducted for the turbulence model, mesh size, and spray parameters prior to optimizing the spray model and validating it with experimental results. While each parameter individually influences the different phases of the injection event, the sensitivity analysis reveals that the break

Zepf, Andreas, Härtl, Martin, Jaensch, Malte

AFR Adaptation Strategy Based on Lambda Sensor for a Methanol Engine

2025-01-703901/31/2025

Methanol is an main type clean energy and it taken important part for the future internal combustion engine technology. The Equivalent air-fuel ratio (AFR) is very import for the engine combustion of methanol. And a lot of case the ratio between methanol and gasoline is not the constant number. There are no studies about AFR when fuel ratio is arbitrary in the currently. The AFR changes obviously if the tank was fueled with gasoline by mistake at a methanol spark ignition engine. Emission will be affected heavily at this situation because the AFR of gasoline is 2 times more than methanol. Some fuel trim adaptation error will be detected by engine controller or even the engine will stall if engine controller keep use the previous AFR to do the fuel injection control. The Investigation provide a relevant AFR adaption strategy based on lambda sensor and the fuel pipes configuration. The strategy was proved valid by some simulation cases to reduce lambda disturbance, optimize emission

Liu, Yiqiang, Zhong, Jun, Qian, Pengfei, Qiao, Zhiwei, Zhu, Delei, Zhong, Shuanglei, Dong, Yanzhao, Yu, Xiuju

AIRS12242024 (Current)12/24/2024

A-20A Crew Station Lighting

AIR12122024A (Current)12/12/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

ARPTEST3008A (Current)12/12/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

AIR12092024 (Current)12/09/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

3D-Printed Reactor Core Makes Solar Fuel Production More Efficient

TBMG-5219312/01/2024

In recent years, engineers at ETH Zurich have developed the technology to produce liquid fuels from sunlight and air. In 2019, they demonstrated the entire thermochemical process chain under real conditions for the first time, in the middle of Zurich, on the roof of ETH Machine Laboratory. These synthetic solar fuels are carbon neutral because they release only as much CO2 during their combustion as was drawn from the air for their production. Two ETH spin-offs, Climeworks and Synhelion, are further developing and commercializing the technologies.

Automation 1730608826599

AIR12349999 (Current)11/08/2024

Automation Test Scope

Experimental Study on Quality Control and Variable Valve Timing Strategy of Hydrogen Engine for High Efficiency and Low Emission at Low Load

2024-01-509510/15/2024

In order to reduce the pumping loss of low loads and maximize the lean combustion advantage of hydrogen, the paper proposes a load control strategy based on hydrogen mass, called quality control, for improving thermal efficiency and emissions at low loads. The advantages of quality control and the effect of VVT on the combustion performance of hydrogen internal combustion engines under low loads were discussed. The results show that when the relative air–fuel ratio (λ) increases to more than 2.5, the NOx emissions are reduced to less than 3.5 g/kW · h at the brake mean effective pressure (BMEP) below 8 bar, especially when the BMEP is less than 5 bar, the NOx is within 0.2 g/kW · h. Compared to quantity control based on air mass, the quality control strategy based on hydrogen mass achieves over a 2.0% reduction in pumping loss at BMEP levels lower than 4.4 bar. Furthermore, it enhances thermal efficiency by up to 5% at low loads, while maintaining NOx emissions within 0.2 g/kW · h at

Li, Yong, Chen, Hong, Fu, Zhen, Du, Jiakun, Wu, Weilong

OIL AEROSOL EMISSION OPTIMISAITON IN HIGH POWER DIESEL ENGINE USING DEFLECTORS IN TURBO CHARGER OIL DRAIN CIRCUIT

2024-26-004701/16/2024

Closed crankcase ventilation prevent harmful gases from entering atmosphere thereby reducing hydrocarbon emissions. Ventilation system carries blowby gases leaking through combustion process along with oil mist to Engine intake system. Major sources of blowby often occurs from leak in combustion chamber through piston rings, leaks from turbo shafts & valve guides. Oil mist carried away by blowby gases gets separated using filtration media. Fleece type separation media has high separation efficiency for particles above 10 microns. Efficiency drops if mist particle is below 10-micron size. Low size aerosol mist generally forms due to flash boiling on piston under crown area and on shafts of turbo charger due to high speeds combined with elevated oil temperatures. High power density diesel engine is taken for our study. It produces low particle size oil mist which contributes to aerosol emission of 3 gm/hr when operated at rated speed. Particle size measurement done using light refraction

M, Velshankar, Dharan R, Bharani, DHADSE, ASHISH, Permude, Ashok, Loganathan, Sekar

Optimizing Closed Loop Air Mass Control in Naturally Aspirated Engines: A Differential Pressure Sensor Approach to meet BS6 Emission Norms

2024-26-014701/16/2024

In order to meet stringent emission targets and to achieve better fuel efficiency, closed loop air mass control strategies have become essential across all vehicle segments. Closed loop air mass control mandates measuring fresh air mass entering the engine combustion chamber. However, in Naturally Aspirated (NA) engines, while measuring air mass using conventional methods such as Hot Film Air mass (HFM) sensor, heavy pulsations in the Air-intake results in errors which would impact closed loop air mass control and lead to inconsistencies in emissions. To address this issue, we studied different approaches using HFM sensor with Resonator, differential pressure sensor across the intake air filter and Lambda based air mass control. Based on this empirical study we found that modelling air mass with differential pressure sensor using Bernoulli’s principle (Flow rate ∝ √Differential pressure) results in higher accuracies compared to conventional methods. This solution gives accurate, cost

Y, Pavan, Shanmugam, Balaji, R, Rachana

Experimental And Numerical Investigation of a Single-Cylinder Methanol Port-Fuel Injected Spark Ignition Engine for a Heavy-Duty Applications.

2024-26-007201/16/2024

With the increasing focus on reducing CO2 emissions to combat global warming and climate change, the automotive industry is exploring near zero-emission alternative fuels to replace traditional fossil-based fuels like diesel, gasoline, and CNG. Methanol is a promising alternative fuel that is being evaluated in India due to its easy transportation and storage, as well as its production scalability and availability potential. This study focuses on the retro-fitment solution of M100 (pure methanol) SI port-fuel injection (PFI) mode of combustion. A heavy duty single-cylinder engine test setup was used to assess methanol SI combustion characteristic. Lean operation strategy has been investigated. At lean mixture conditions a significant drop in NOX and CO emissions was achieved. The fuel injection techniques and the impact of exhaust gas recirculation (EGR) on the conventional stoichiometric combustion process is highlighted. Increase of the EGR ratio at stoichiometric operation led to 3

Singh, Inderpal, Güdden PhD, Arne, Raut PhD, Ankit, Emran, Ashraf, Dhongde PhD, Avnish, Sharma, Vijay, Wagh, Sachin

Hydrogen Internal Combustion Engine Strategies for Heavy-Duty Transportation: Engine and System Level Perspective

2024-26-017501/16/2024

Hydrogen internal combustion engines (H2 ICE) offer a cost-effective solution to decarbonize transport by combining a carbon-neutral fuel with the mature and established internal combustion engine technology. While vehicles running with hydrogen have been demonstrated over the years, this fuel's physical and chemical properties require modifications and upgrades on the vehicle from an engine and system-level perspective. In addition, market-specific regulatory and economic factors can also constrain the realization of optimal hydrogen powertrain architectures. Therefore, this paper reviews the impact of hydrogen use on combustion, injection, air management, and after-treatment systems, indicating the different strategies used to enable effective H2-ICE strategies from an efficiency, cost, and safety standpoint. Specifically, swirl and tumble-based combustion systems using port fuel injection, low-pressure, and high-pressure direct injection are discussed to review performance, cost

Sari, Rafael, Shah, Ashish, Kumar, Praveen, Cleary, David, Rairikar, Sandeep, Sonawane, Shailesh Balkrishna

Cost Effective Pathways Toward Highly Efficient and Ultra-Clean CI Engines, Part I: Combustion System Optimization

2024-26-003701/16/2024

Following global trends of increasingly stringent greenhouse gas (GHG) and criteria pollutant regulations, India will likely introduce within the next decade equivalent Bharat Stage (BS) regulations for Diesel engines requiring simultaneous reduction in CO2 emissions and up to 90% reduction in NOx emission from current BS-VI levels. Consequently, automakers are likely to face tremendous challenges in meeting such emission reduction requirements while maintaining performance and vehicle total cost of ownership (TCO), especially in the Indian market which has experienced significant tightening of emission regulation during the past decade. Therefore, it is conceivable that cost effective approaches for improving existing diesel engines platforms for future regulations would be of high strategic importance for automakers. In this first of a two-part article, cost effective means of improving the combustion process in a Diesel engine to reduce engine-out emissions, specifically of NOx and

Shah, Ashish, Kumar, Praveen, Sari, Rafael, Cleary, David, Gothekar, Sanjeev, Thipse, Sukrut S

A Mid-Infrared Laser Absorption Sensor for Gas Temperature and Carbon Monoxide Mole Fraction Measurements at 15 kHz in Engine-Out Gasoline Vehicle Exhaust

03-17-01-000201/16/2024

Quantifying exhaust gas composition and temperature in vehicles with internal combustion engines (ICEs) is crucial to understanding and reducing emissions during transient engine operation. This is particularly important before the catalytic converter system lights off (i.e., during cold start). Most commercially available gas analyzers and temperature sensors are far too slow to measure these quantities on the timescale of individual cylinder-firing events, thus faster sensors are needed. A two-color mid-infrared (MIR) laser absorption spectroscopy (LAS) sensor for gas temperature and carbon monoxide (CO) mole fraction was developed and applied to address this technology gap. Two quantum cascade lasers (QCLs) were fiber coupled into one single-mode fiber to facilitate optical access in the test vehicle exhaust. The QCLs were time-multiplexed in order to scan across two CO absorption transitions near 2013 and 2060 cm–1 at 15 kHz. This enabled in situ measurements of temperature and CO

Airlines Electronic Engineering Committee

test download manager cache issue 12/27/2023 at 9 am

SAE-PP-0908512/27/2023

test download manager cache issue 12/27/2023 at 9 am

Mutagaana, Festo

Regression 11/1/23

SAE-PP-0892211/01/2023

Mutagaana, Festo

Experimental and Numerical Investigation of Combustion and Noise, Vibrations, and Harshness Emissions in a Drone Jet Engine Fueled with Synthetic Paraffinic Kerosene

08/14/2023

Emissions and effects of climate change have prompted study into fuels that reduce global dependence on traditional fuels. This study seeks to investigate engine performance, thermochemical properties, emissions, and perform NVH analysis of Jet-A and S8 using a single-stage turbojet engine at three engine speeds. Experimental Jet-A results were used to validate a CFX simulation of the engine. Engine performance was quantified using thermocouples, pressure sensors, tachometers, flow meters, and load cells fitted to the engine. Emissions results were collected using an MKS Multigas Emissions Analyzer that examined CO, CO₂, H₂O, NOx, and THC. NVH analysis was conducted using a multifield, free-field microphone, and triaxial accelerometer. This study found that Jet-A operates at higher temperatures and pressures than S8, and S8 requires higher fuel flow rates than Jet-A, leading to poorer efficiency and thrust. S8 produced stronger vibrations over 5 kHz compared to Jet-A. S8 showed a

Soloiu, Valentin, Mcafee, John, Ilie, Marcel, Rowell, Aidan, Willis, James, Dillon, Nicholas

Ducted Fuel Injection Provides Consistently Lower Soot Emissions in Sweep to Full-Load Conditions

07/14/2023

Abstract Earlier studies have proven how ducted fuel injection (DFI) substantially reduces soot for low- and mid-load conditions in heavy-duty engines, without significant adverse effects on other emissions. Nevertheless, no comprehensive DFI study exists showing soot reductions at high- and full-load conditions. This study investigated DFI in a single-cylinder, 1.7-L, optical engine from low- to full-load conditions with a low-net-carbon fuel consisting of 80% renewable diesel and 20% biodiesel. Over the tested load range, DFI reduced engine-out soot by 38.1–63.1% compared to conventional diesel combustion (CDC). This soot reduction occurred without significant detrimental effects on other emission types. Thus, DFI reduced the severity of the soot–NOx tradeoff at all tested conditions. While DFI delivered considerable soot reductions in the present study, previous DFI studies at low- and mid-load conditions delivered larger soot reductions (>90%) compared to CDC operation at the same

Buurman, Noad J., Nyrenstedt, Gustav, Mueller, Charles J.

Ducted Fuel Injection Provides Consistently Lower Soot Emissions in Sweep to Full-Load Conditions

03-19-01-0001-TEST-REC07/14/2023

Abstract Earlier studies have proven how ducted fuel injection (DFI) substantially reduces soot for low- and mid-load conditions in heavy-duty engines, without significant adverse effects on other emissions. Nevertheless, no comprehensive DFI study exists showing soot reductions at high- and full-load conditions. This study investigated DFI in a single-cylinder, 1.7-L, optical engine from low- to full-load conditions with a low-net-carbon fuel consisting of 80% renewable diesel and 20% biodiesel. Over the tested load range, DFI reduced engine-out soot by 38.1–63.1% compared to conventional diesel combustion (CDC). This soot reduction occurred without significant detrimental effects on other emission types. Thus, DFI reduced the severity of the soot–NOx tradeoff at all tested conditions. While DFI delivered considerable soot reductions in the present study, previous DFI studies at low- and mid-load conditions delivered larger soot reductions (>90%) compared to CDC operation at the same

Buurman, Noad J., Nyrenstedt, Gustav, Mueller, Charles J.

Ion Current Sensing as Combustion Diagnostics for a Spark-Ignited Natural Gas-Hydrogen Engine

2023-01-120406/26/2023

The use of hydrogen as an alternative fuel to power cogeneration gas engines has been a research topic over the last few decades and has currently gained importance, even more due to current circumstances related to decarbonisation efforts for the energy supply. A significant part of the research done is focused on the topic of combustion diagnostics, which can be fulfilled through different methods. This work investigates the feasibility of the ion current sensing for a pure hydrogen fueled series natural gas cogeneration engine. For this purpose, a variation of the fuel composition (100% natural gas to 100% hydrogen) was carried out while maintaining the indicated mean effective pressure (IMEP) and the combustion phasing (CA50). This demonstrated that the efficiency increased monotonically as the hydrogen concentration rose. Simultaneously, the ion current signal gradually dropped but was still detectable at 100% hydrogen combustion. To better understand this effect, 0D simulations

Salim, Naqib, Beltaifa, Youssef, Kettner, Maurice, Loose, Oliver, Weißgerber, Tycho, Züfle, Michael, Pöhlmann, Klaus, Berlet, Peter

Methods for the Holistic Evaluation of the eFuel Influence on Gasoline Engine Combustion

2023-01-121006/26/2023

The proportion of new registrations with battery-electric and hybrid powertrains is rising steadily. This shows the strong trend in the automotive industry away from conventional powertrains with internal combustion engines. The aim is to reduce the transport sector's contribution to CO2 emissions. However, it should be noted that this only applies when renewable energy is used. Studies show the relevance of the sytem boundaries under consideration, which makes the application of Life Cycle Assessment indispensable. According to these studies, the various types of powertrains differ only slightly in their greenhouse gas impact. Rather, the energy supply chain plays a significant role. Moreover, a ban on combustion engines would lead to an additional increase in cumulative CO2 emissions. An important aspect on the way to sustainable mobility solutions is addressing the existing fleet. The approximately 1.25 billion vehicles that are predominantly powered by internal combustion engines

Villforth, Jonas, Vacca, Antonino, Bargende, Michael, Kulzer, Andre

Investigation of spark plug and passive pre-chamber ignition on a single-cylinder engine with hydrogen port fuel injection

2023-01-120506/26/2023

The race towards zero carbon emissions is ongoing with the need to reduce the consumption of fossil energy resources. This demands immediate and reliable developments regarding technical environmentally friendly solutions for the power and transportation sectors. An alternative way to achieve a carbon-free powertrain is the use of green hydrogen for internal combustion engines. Operating a hydrogen-fuelled engine offers many opportunities as well as challenges that need to be addressed. In this work the self-designed Fraunhofer single cylinder engine with a displacement volume of 500 cm³ derived for extreme lean combustion and passive pre-chamber ignition was adapted for hydrogen engine operation. With hydrogen combustion, the customized cooling system resulting in low metal temperatures is simulated and optimized to avoid hot spots in the combustion chamber. The basic engine setup being investigated on the test bench contains a compression ratio of 12.2, port fuel injection and a

Bucherer, Sebastian, Rothe, Paul, Sobek, Florian, Gottwald, Theo, Kraljevic, Ivica, Vacca, Antonino, Gal, Thomas, Chiodi, Marco, Kulzer, Andre

Comparison of conventional vs reactivity-controlled compression ignition diesel-hythane dual-fuel combustion: An investigation on engine performance and emissions at low-load

2023-01-120306/26/2023

The exponential rise in greenhouse gas (GHG) emissions into the environment is one of the major concerns of international organisations and governments. As a result, lowering carbon dioxide (CO2) and methane (CH4) emissions has become a priority across a wide range of industries, including transportation sector, which is recognised as one of the major sources of these emissions. Therefore, cleaner powertrain technologies, such as the use of alternative fuels and combustion modes in internal combustion engines, are required. Dual-fuel operation with high substitution ratios using low carbon and more sustainable fuels can be an effective short-term solution. Hythane, a blend of 20% hydrogen and 80% methane, could be a potential solution to this problem. In this research, two alternative diesel-hythane dual-fuel modes, namely conventional dual-fuel (CDF) combustion and reactivity-controlled compression ignition dual-fuel (RCCI DF) combustion, were experimentally evaluated and compared to

Longo, Kevin, Wang, Xinyan, Zhao, Hua

A fast and reliable CFD approach to design hydrogen SI engines for industrial applications

2023-01-120806/26/2023

SI engines fueled with hydrogen represent a promising powertrain solution to meet the ambitious target of carbon-free emissions at the tailpipe. Therefore, fast and reliable numerical tools can significantly support the automotive industry in the optimization of such technology. In this work, a 1D-3D methodology is presented to simulate in detail the combustion process with minimal computational effort. First, a 1D analysis of the complete engine cycle is carried out on the user-defined powertrain configuration. The purpose is to achieve reliable boundary conditions for the combustion chamber, based on realistic engine parameters. Then, a 3D simulation of the power-cycle is performed to mimic the combustion process. The flow velocity and turbulence distributions are initialized without the need of simulating the gas exchange process, according to a validated technique. However, coupled 1D-3D simulations of the engine scavenging can be carried out as well to increase the accuracy of the

Ramognino, Federico, Sforza, Lorenzo, Cerri, Tarcisio, Lucchini, Tommaso, Onorati, Angelo, Novella, Ricardo

Sound Design for Electric Vehicles: Enhancing Safety and User Experience Through Acoustic Vehicle Alerting System (AVAS)

2025-01-006805/05/2023

Silent engines are an excellent strategy to combat noise pollution. Still, they can pose risks for pedestrians who rely on auditory cues for safety and reduce driver awareness due to the absence of the familiar sounds of combustion engines. Sound design for silent engines not only tackles the above issues but goes beyond safety standards towards a user-centered approach by considering how users perceive and interpret sounds. This paper examines the evolving field of sound design for electric vehicles (EVs), focusing on Acoustic Vehicle Alerting Systems (AVAS). The study analyzes existing AVAS, classifying them into different groups according to their design characteristics, from technical concerns and approaches to aesthetic properties. Based on the proposed classification, an (adaptive) sound design methodology, and concept for AVAS are proposed based on state-of-the-art technologies and tools (APIs), like Wwise Automotive, and integration through a functional prototype within a

Esteves, Raquel, Campos Magalhães, Eduardo Miguel, Bernardes, Gilberto

Development of Offline Simulation Software for Active Sound Design in Electric Vehicles

2025-01-001705/05/2023

With the increasing adoption of electric vehicles (EVs), Active Sound Design (ASD) has emerged as a crucial method to enhance both the sound quality and driving experience, addressing the lack of distinctive engine sounds present in internal combustion vehicles. This paper presents an ASD offline simulation software developed on the MATLAB platform to address these challenges. The software integrates a vehicle dynamics model with three key sound synthesis algorithms: order synthesis, pitch shifting, and granular synthesis, allowing for comprehensive control strategy development, real-time sound playback, and rapid adjustment. The software consists of several functional modules, including configuration, order generator, pitch shifting, and granular synthesis interfaces, which support user-friendly operation and flexible sound parameter adjustments. Users can simulate different driving conditions and evaluate the acoustic performance of the ASD system in real time. The system also allows

Qian, Yushu, Liu, Zhien, xiong, chenggang

Optimization of HEV Vehicle’s Engine Modulated Noise

2025-01-008405/05/2023

One 1.5L Miller-cycle turbocharged four cylinder gasoline hybrid engine is installed on a certain hybrid vehicle. When accelerating at low to medium speeds with a small throttle, there is a "da da" knocking noise inside the car, which seriously affects the overall sound quality of the vehicle. By analyzing the vibration and noise data of the engine, it was found that the frequency of the abnormal knocking sound is 200-1000Hz, which presents a half order characteristic in the time domain, that is, one knocking occurs when the engine crankshaft rotates twice. Through Hilbert demodulation analysis of the vibration data in the problem frequency range, it was found that the knocking noise was modulated in the frequency domain, with a modulation frequency of half of the crankshaft rotation frequency. By building a fully flexible multi-body dynamic model of a hybrid powertrain and inputting the engine's cylinder pressure excitation, the combustion excitation is coupled with mechanical

The accelerated roughness noise optimization of one PHEV vehicle

2025-01-008705/05/2023

To optimize the ’kalakala’ noise that produced by the plug hybrid electric vehicle when accelerating with a small throttle while in the charging state. A LMS device was used to acquire the noise of the driver's outer ear . Through filtering and playback analysis, it was confirmed that the noise is mainly contains the frequency bands of 250-350Hz, 350-500Hz, and 500-700Hz. The three frequency bands of the noise were used as carriers for Hilbert transform, and their envelopes were obtained for Fourier transform analysis. It was found that the modulation order of the noise is 0.5 times that of the engine ignition order, and the modulation frequency is 20-30Hz, which let the customer hears like roughness. Regarding the spectral characteristics of this noise, firstly, at the excitation source, the impact of reducing engine combustion excitation on this noise is explored. At the same time, selected a reasonable moment of inertia and frequency of the pulley torsional damper, to decrease the

Shouhui, Huang, YUN, ZHAO, zhou, changshui

Plug-in hybrid and range extender NVH – Challenges and Solutions

2025-01-010105/05/2023

The automotive industry continues to develop new powertrain and vehicle technologies aimed at reducing overall vehicle-level fuel consumption. While the use of electrified propulsion systems is expected to play an increasingly important role in helping OEM’s meet fleet CO2 reduction targets, hybridized propulsion solutions can play a vital role in the electrification strategy of vehicle manufacturers. Plug-in hybrid and range extender vehicles show unique NVH challenges due to their different possible operation modes. First, the paper outlines different driveline architectures for PHEV and range extenders. Given the multiple general architectures, as well as operation modes which typically occur for these vehicles, characterizations and source-path analysis of these vehicles can be more complicated than conventional vehicles. In the following steps, typical NVH related challenges are highlighted and potential solutions for NVH optimization are discussed. While the overall noise levels

Wellmann, Thomas, Ford, Alex, Pruetz, Jeffrey

Infrared Signature of Fixed and Variable Area C-D Nozzle of Aircraft Engine

88-16-02-001101/02/2023

The use of converging-diverging (C-D) variable area nozzle (VAN) in military aeroengines is now common, as it can give optimal expansion and control over engine back pressure, for a wide range of engine operations. At higher main combustion temperatures (desired for supercruise), an increase in the nozzle expansion ratio is needed for optimum performance. But changes in the nozzle throat and exit areas affect the visibility of engine hot parts as the diverging section of the nozzle is visible for a full range of view angle from the rear aspect. The solid angle subtended by engine hot parts varies with change in visibility, which affects the aircraft infrared (IR) signature from the rear aspect. This study compares the performances of fixed and variable area nozzles (FAN and VAN) in terms of engine thrust and IR signature of the engine exhaust system in the boresight for the same increase in combustion temperature. This study is performed for two cases: (i) variable throat area and

Baranwal, Nidhi, Mahulikar, Shripad P.

Infrared Signature of Fixed and Variable Area C-D Nozzle of Aircraft Engine

01/02/2023

The use of converging-diverging (C-D) variable area nozzle (VAN) in military aeroengines is now common, as it can give optimal expansion and control over engine back pressure, for a wide range of engine operations. At higher main combustion temperatures (desired for supercruise), an increase in the nozzle expansion ratio is needed for optimum performance. But changes in the nozzle throat and exit areas affect the visibility of engine hot parts as the diverging section of the nozzle is visible for a full range of view angle from the rear aspect. The solid angle subtended by engine hot parts varies with change in visibility, which affects the aircraft infrared (IR) signature from the rear aspect. This study compares the performances of fixed and variable area nozzles (FAN and VAN) in terms of engine thrust and IR signature of the engine exhaust system in the boresight for the same increase in combustion temperature. This study is performed for two cases: (i) variable throat area and

Baranwal, Nidhi, Mahulikar, Shripad P.

Evaluating Class 6 Delivery Truck Fuel Economy and Emissions Using Vehicle System Simulations for Conventional and Hybrid Powertrains and Co Optima Fuel Blends

2022-01-115609/20/2022

The US Department of Energy’s Co-Optimization of Engine and Fuels Initiative (Co-Optima) investigated how unique properties of bio-blendstocks considered within Co-Optima help address emissions challenges with mixing controlled compression ignition (i.e., conventional diesel combustion) and enable advanced compression ignition modes suitable for implementation in a diesel engine. Additionally, the potential synergies of these Co-Optima technologies in hybrid vehicle applications in the medium- and heavy-duty sector was also investigated. In this work, vehicles system were simulated using the Autonomie software tool for quantifying the benefits of Co-Optima engine technologies for medium-duty trucks. A Class 6 delivery truck with a 6.7 L diesel engine was used for simulations over representative real-world and certification drive cycles with four different powertrains to investigate fuel economy, emissions, and well-to-wheel greenhouse gas performance. Comparisons were made between

Vijayagopal, Ram, Curran, Scott, Deter, Dean, Longman, DOUGLAS

USE OF FIBER OPTICS OXYGEN SENSOR FOR AIRCRAFT FUEL TANK INERTING APPLICATION

2022-26-116305/26/2022

Aircraft fuel tanks are high risk zones as the ullage volume contain highly flammable fuel-air mixture. In the past, efforts have been made by various agencies to reduce this risk by designing an inerting system which significantly reduces the flammability risks. Regulations are also in place in order to reduce the potential for flammable vapor spaces in fuel tanks for the passenger aircrafts. One of the ways to reduce this risk is to continuously supply the inert gas like nitrogen to the ullage volume so that oxygen concentration is always kept to a level well below the flammability limit. It is therefore essential to measure continuously and accurately the oxygen concentration in the ullage volume of the fuel tank during entire operation of the aircraft. Current technologies have serious limitations in terms of sensor placement inside or near fuel tank and also in terms of continuous operation. This paper studies the limitations of current technologies available on oxygen measurement

Jha, Rajesh Kumar

Hydrogen Fueled Aircraft Engines

2022-26-115605/26/2022

In the recent years, the climate change has become more devastating, and its continuing use of fossil fuels seems unreasonable as humankind is being pushed into a corner where the need to choose an alternative fuel has become necessary. The two main alternatives currently available are: Electrical propulsion and Hydrogen injected air breathing engines. Electrical propulsion had come far since last 10 years with Li+ ion technology, but the problem with them persists. They provide a low power to weight ratio which reduces the range as well as the load while operating the aircraft. On the other hand, Hydrogen with fuel cells or H2-O2 combustion has a high power to weight ratio but very difficult to handle. So, using hydrogen comes with a lot of difficulties in the present scenario. However. the concept of hydrogen has come a long way since its first use as a Rocket fuel. But this alternate fuel provides many advantages as well as challenges which needs to be overcome to move on its use in

Sri, Ratan, Sivamani, Seralathan

A Computational performance study on cheaper fuels for Micro Jet Engine as Jet A1 replacement without performance penalties

2022-26-115505/26/2022

Micro Jet Engines are used in UAVs, MAVs, and missiles increasingly. Even though they have a lower thermal efficiency, they have a higher thrust to weight ratio and endurance than electric motors. This lower thermal efficiency incurs expensive fuels and higher fuel consumption. The purpose is to test the performance of a designed Micro jet Engine with cheaper ethanol, kerosene, and automotive diesel. As diesel has a higher energy density and heating value than Jet A1, it outperforms jet a1. The ordinary refined kerosene is also tested. At a nominal air fuel ratio of 60, i.e., 1.5 g/s for this designed 0.086 kg/s engine air flow rate, all three fuels perform approximately the same in steady state simulations, as per steady state simulations : kerosene provides 2240 K, jet a1 provides 2311 K, the ethyl alcohol provides 2350 K and kerosene burns at 2274 K. These steady state simulation results is better for performance comparison between the fuels while for real time combustion exit

A, Adithya, Renald, C J Thomas

Frequency Coupling Analysis in Spark Ignition Engine Using Bispectral method and Ensemble Empirical Mode Decomposition

2022-01-057603/29/2022

Internal combustion (IC) engines are the current dominant power source used in the automotive industry for hybrid vehicles. The combustion process of IC engines involves various parameters, which are linked to the overall performance of the driveline. Therefore, finding the frequency coupling between the manifold pressure, in-cylinder pressure and output crankshaft speed will provide an understanding of torque fluctuations and its effect on driveline performance. The present work introduces a methodology to analyse cylinder pressure, manifold pressure and instantaneous crank speed signals measured from a 4 cylinder, 1.6 Litre, Gasoline Direct Injection Engine at different speed and loading conditions in order to identify the frequency coupling between these signals. This work uses Ensemble Empirical Mode Decomposition (EEMD) for de-noising the signals and Bispectral analysis for examining the presence of a frequency coupling from the signals. This paper will demonstrate the systematic

El Yacoubi, Ismail, Samuel, Stephen

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