4气门柴油机缸内涡流形成的试验研究

在稳流气道试验台上,利用热线风速仪对4气门柴油机缸内流场进行了测量,研究了该柴油机缸内进气涡流的形成过程,揭示了进气过程气体流动的特点和规律,并从湍流的角度分析了缸内气流的发展与衍变.研究结果表明,在气缸盖出口流场,气流变化较强烈,湍流强度高,难以形成明显的刚性涡流;沿着气缸向下,由于湍流的作用使缸内流场不断衰减并均匀化,在较远处形成稳定的涡流.

EXPERIMENTAL STUDY OF THE FORMATION OF INTAKE SWIRL IN THE CYLINDER OF A 4-VALVE DIESEL ENGINE

Hot wire anemometer was applied to test the air flow field within the cylinder of a 4-valve diesel engine by steady flow measuring equipments. The process of formation of intake swirl in the engine was investigated. Characteristics of the air flow in the cylinder were discussed. In addition, the development and evolution of air flow in the cylinder were analyzed.It is shown that at the outlet of cylinder head air flow changes strongly and there is high turbulent intensity so it is difficult to be come an obvious swirl. Down the cylinder, air flow affected by the turbulence continuously attenuates and shapes itself into a steady swirl.