1 前言无论对于汽车拖拉机用或者渔船以及其他牵引用柴油机,由于加速以及负载特性的要求,在设计一台柴油机时对于提高低转速下的扭矩都予以十分重视。柴油机为了提高功率而采取涡轮增压以后,特别是在今后增压压力逐步提高的发展趋势下,如何提高低转速下的扭矩问题更为突出.这里的主要原因在于活塞式发动机与涡轮压气机之间的气体流动特性是不 1 INTRODUCTION In designing a diesel engine, great attention has been paid to improving the torque at low revolutions, both for tractors for tractors and for fishing trains, as well as for other traction diesel engines due to acceleration and load characteristics requirements. After the turbocharging is adopted to increase the power of the diesel engine, especially under the development trend of gradually increasing the supercharging pressure in the future, how to improve the torque problem under the low speed is more prominent. The main reason here is that the piston engine and the turbo compressor Gas flow between the characteristics is not