The effect of pre-chamber position and injection direction on a novel hydrogen direct injection stratified combustion rotary engine

The hydrogen direct injection stratified combustion rotary engine (HDSIC-RE) is a new type of RE based on the pre-chamber(PC) concept. Supplying hydrogen in PC can effectively control the knocking of the hydrogen Wankel rotary engine(HWRE). However, HDISC suffers from the problem of an excessive proportion of unburned hydrogen and low thermal efficiency. Therefore, this study proposes changing the position of the PC(potP) and the hydrogen injection direction of HDISC to solve the problem. The results show that different potP can reduce the inhomogeneity index or increase the diffusion distance of hydrogen. The injection towards the rear of the combustion chamber is more conducive to combustion. The potP moves in the opposite direction of the rotor rotation, which can effectively reduce the amount of unburned hydrogen. The rear injection of poPt at the L4 position can reduce the amount of unburned hydrogen by 55.6 %. However, potP has less effect on the combustion process and control of high-pressure position, because the flow field is insensitive to the change of potP. Whereas, the injection to the rear of the combustion chamber with a shift in potP can enhance the ITE of HDISC. The highest ITE can be achieved by maintaining the same configuration at poPt with rear injection, which represents an improvement of 12.98 % compared to the past. The results show that the change of potP and injection direction can effectively solve the problem of HDISC. This is making HDISC become a promising HWRE.