Internal Combustion Engine
Ali Shaafi; Mohammad Javad Noroozi; Vahid Manshaei
Abstract
In this computational research, the separate and simultaneous impacts of diesel direct injection timing, fuel spraying cone angle, and hydrogen gas addition on combustion characteristics, output emissions, and performance in a single-cylinder direct injection diesel engine was studied. In order to conduct ...
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In this computational research, the separate and simultaneous impacts of diesel direct injection timing, fuel spraying cone angle, and hydrogen gas addition on combustion characteristics, output emissions, and performance in a single-cylinder direct injection diesel engine was studied. In order to conduct the simulations, valid and reliable models for combustion, break-up, and for turbulence was used. The effects of fifteen fuel injection strategies based on characteristics such as time of fuel spraying (-15, -10 CA BTDC, and TDC) and nozzle cone angle (105, 115, 125, 145, and 160 degrees) under neat diesel combustion and diesel-hydrogen combustion engine operations conditions were explored. The obtained results indicated that the addition of H2 due to significant heating value has increased indicated power and improved indicated specific energy consumption at the expense of NOx emissions but considerably decreased CO and soot emissions simultaneously. By advancing injection timing, maximum pressure peak point, maximum temperature peak point, and maximum heat release rate peak point have increased and caused lower indicated specific energy consumption. However, using a wide spray angle (e.g., 160 cone degrees), resulted in lower indicated power and higher indicated specific energy consumption due to more fuel could spray in regions with lower oxygen concentrations compared to baseline operation case.
Energy Science and Technology
Saeed Ahmadipour; Mohammad Hossein Aghkhani; Javad Zareei
Abstract
Start of fuel injection and fuel type are two important factors affecting engine performance and exhaust emissions in internal combustion engines. In the present study, a one-dimensional computational fluid dynamics solution with GT-Power software is used to simulate a six-cylinder diesel engine to study ...
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Start of fuel injection and fuel type are two important factors affecting engine performance and exhaust emissions in internal combustion engines. In the present study, a one-dimensional computational fluid dynamics solution with GT-Power software is used to simulate a six-cylinder diesel engine to study the performance and exhaust emissions with different injection timing and alternative fuels. Starting the fuel injection was from 10 °CA BTDC to the TDC with an interval between two units and from alternative fuel bases (diesel), including methanol, ethanol, diesel, and ethanol compounds, biodiesel and decane was used. To validate the model, a comparison is made between simulation data and experimental data (including torque and power) showing the validation error is less than 6.12% and indicating the software model validation. Also, the modeling results show that decane fuel has higher brake power and brake torque of more than 6.10 % while fuel is injected at 10 °CA BTDC compared to the base fuel, and illustrates a reduction of 5.75 % in specific fuel consumption due to producing higher power. In addition, with the advance of injection timing compared to baseline, the amount of CO and HC in biodiesel fuel reduces to 83.88% and 64.87%, respectively, and the lowest NOX emission with the retardation of starting injection, to decane fuel is awarded. In general, the results show that decane fuel could be a good alternative to diesel fuel in diesel engines when it starts fuel injection at 10 °CA BTDC.
