Abstract
The spoiler is vital for optimizing rotary engines, yet its impact on the flow and combustion process within the cylinder remains ambiguous, thereby impeding the optimization efforts for rotary engines. This paper proposes the concept of pressure differential flow, highlighting its significance in understanding the local pressure variations within the cylinder resulting from interactions among the combustion chamber, cylinder body, and spoiler structure. We analyze the direct influence of spoiler height on this flow phenomenon, emphasizing its importance. The results show that when the spoiler height is greater than 75% of the maximum height, the pressure difference flow is more obvious, and its intensity increases with the increase in the spoiler height. At this time, there are both pressure difference flow and forced flow caused by the spoiler in the cylinder. When the spoiler height is less than 75% of the maximum height, the pressure difference flow is not obvious, and the forced flow caused by the spoiler is dominant in the cylinder. Pressure differential flow can reduce ignition delay and increase the maximum cylinder pressure, but it can also delay ignition timing and reduce combustion stability.
