中文摘要：

以二维数值模拟为基础,研究了锥顶型燃烧室内的冲击波发展的震荡过程,得到作用于活塞不同位置处的超压分布。模拟结果表明：由于燃烧室结构的独特性,导致冲击波能在特定区域进行汇聚,致使该区域超压明显高于其他区域。将该模拟结果与实际破坏失效的活塞进行对比,发现冲击波汇聚区域往往就是活塞被破坏的地方。数值模拟结果与实际破坏结果吻合很好。这为设计燃烧室形状以避免冲击波对活塞造成破坏提供了理论基础。

英文摘要：

For the internal-combustion engine, super knock produced by new combustion system may cause detonation in combustion chamber, which may damage the piston. 2D numerical simulation which is conducted by Ansys Fluent is used to investigate the propagation and reflection of detonation wave produced in combustion chamber with cone type roof. The overpressure distribution on top pis- ton surface is obtained. Numerical simulation showed that the detonation wave could converge in spe- cial zone because of the shape of combustion chamber, which made the overpressure there much high- er than that in the other zones. The numerical results were compared with the experimental damaged pistons, and it＇s found that the converging of the detonation wave found in numerical simulation could be the reason that causes the piston local region damaged under super knock. The results obtained in the study provided an important reference to the shape design of combustion chamber in order to avoid piston from being damaged by the detonation wave.