直喷式柴油机缸内紊流及其对柴油机性能影响的研究

An Investigation of In Cylinder Turbulence and Its Effects on the Performance of a D.I. Diesel Engine

本文介绍了由不同几何形状的进气扰动片和燃烧室产生的进气紊流和挤压紊流对直喷式柴油机性能影响的研究。缸内紊流测量是用热线风速仪在倒拖发动机试验台上进行的。试验表明：由进气扰动片产生的进气紊流不能保持到进气终了，因此进气扰动片对柴油机性能的影响是由于进气涡流的变化所致；由燃烧室形状增强的挤压紊流可使柴油机烟度明显改善。

This paper reports the investigation of the effects of the intake turbulence and the squish turbulence on the performance of a D.I. diesel engine. The in cylinder turbulence is measured under the condition of a motored engine by using a hot wire anemometry. The results show that the intake turbulence which is generated during the intake stroke by fixing different geometry shape flaps in an intake port declines so quickly that it almost disappears when the intake stroke ends, the effect of the turbulence flap on engine performance is merely due to the change of the in cylinder intake swirl constructure. A significant intensification of squish turbulence due to the strong squish and/or counter squish near TDC with the “squish lip” or “turbulence rim” geometry of combustion chamber greatly decreases exhaust smoke, but makes hardly improvement on fuel economy.