Numerical Investigation of the In‐cylinder Flow Characteristics of Hydrogen Fueled Internal Combustion Engine

This paper addresses the computational fluid dynamics (CFD) simulation to investigate the in‐cylinder flow characteristics of 2D combustion chamber for a hydrogen fueled four‐stroke internal combustion engine. CFD simulation has been carried out using commercial CFD codes. The engine speed was varied 1000 to 3000 rpm, the range of equivalent ratio of 0.6 to 1.0 and crank angle are varied 0 to 720 degree in this study. The effect of engine speed and equivalence ratio on the flow field characteristics and volumetric efficiency are investigated at motoring condition. The increase of engine speed gives more efficient diffusion process for hydrogen and gives more homogeneity of air‐fuel mixture structure. The characteristics of the flow field are presented by the in‐cylinder pressure and temperature distribution as well as the contours of hydrogen mass fraction for different engine speed. The acquired results show that the maximum in‐cylinder temperature and pressure obtained of 650 K and 1.143 MPa at engine speed 3000 rpm respectively. It can be seen that the engine speed and equivalence ratio are strongly related to the volumetric efficiency. The results show that the volumetric efficiency increases linearly with increases of engine speed, while decreases with increases of equivalence ratio. The obtained results from the simulation can be employed to examine the homogeneity of air‐fuel mixture structure for better combustion process and engine performance.

Keywords: Hydrogen fueled engine, CFD, equivalence ratio, in‐cylinder, engine speed, volumetric
efficiency.

M.M.Noor