直接喷射式柴油机进气道的结构与性能影响着柴油机的动力性和经济性指标。经过对长征8V120FQ 型柴油机进气道所作的试验研究,找到它存在的问题。在此基础上为本柴油机设计了几种螺旋进气道。在气道模拟试验台上,经过多次试验选出了一种较好的螺旋气道。与原气道比较;进气阻力△p 有明显下降,气道流通特征值μσ有所提高,涡流比Ω达到适宜的程度。可以预见使用这种气道对于柴油机的性能指标将有一定程度的提高。 The structure and performance of direct injection diesel engine inlet affect the dynamic and economic indexes of diesel engine. After the long march 8V120FQ diesel engine intake test made to find its existing problems. Based on this, several helical air intakes are designed for this diesel engine. In the airway simulation test bench, after a number of tests to choose a better spiral airway. Compared with the original airway, the air intake resistance △ p decreased obviously, and the characteristic value μσ of airway circulation increased, and the eddy current ratio Ω reached the appropriate level. It can be foreseen that using this airway will improve the performance index of diesel engine to a certain extent.