改善495汽油机燃烧性能的分析研究

Investigation of Improving Combustion Performance of Model 495 Gasoline Engine

基于三维CFD软件FIRE,计算分析了495汽油机的进气燃烧过程特性。研究结果表明:4气门汽油机进气过程中存在着双涡运动特性,其中,排气门侧的涡团因不断地吸取能量而增强;而进气门侧的涡团由于能量耗散而衰减。调整气道倾斜角参数α、β、θ,使得高湍动能区向火花塞靠近,从而显著提高燃烧速率;调节α、β倾斜角比调节θ倾斜角对缸内滚流强度的影响更加明显。

Based on the 3-dimensional software FIRE, the intake and combustion process of model 495 gasoline engine was numerically studied. Results indicate that the dual-eddy structure is presented during intake process of the 4-valve engine. The eddy on the exhaust valve side is intensified with the increasing energy while the eddy on the intake valve side is weakened due to the energy dissipation. The combustion rate can be remarkably increased by adjusting port angle parameters α,β and θ because of the enhanced tumble motion near the spark plug, among them the effect of parameter α and β on the in-cylinder tumble intensity is more obvious than that of the parameter θ.