A computational investigation into the effects of piston bowl geometry on fuel-air mixing and performance in a high-intensified diesel engine

A computational investigation is performed to evaluate the effects of piston bowl geometry on fuel-air mixing and engine performance in a high-intensified diesel engine. Fourteen different shapes of diesel engine piston bowl are selected and simulated by CFD FIRE. The main results suggest that an optimal value exist to maximize indicated power, respectively, of piston bowl diameter, re-entrant angle and bowl bottom radius. Piston bowl diameter and bowl bottom radius are found to have a more significant impact on performance than re-entrant angle. Because variations of piston bowl diameter and bowl bottom radius are found to have a bigger effect on piston bowl geometry, which mainly affect fuel-air mixing process near bowl side-wall and bottom of central convexity, resulting in marked effects on combustion process and performance. This study underlines the need to carefully consider fuel-air mixing process induced by piston bowl geometry.