基于数值模拟的螺旋进气道结构优化

Optimization of Helix Intake Port Based on Numerical Simulation

以实际产品为研究对象,将三维数值模拟方法应用于柴油机螺旋进气道的改进设计中。通过数值模拟,获得了该气道内气体的流速、压力及湍动能等特性参数的分布,并计算了出口处的流量系数和绕竖直轴线的转矩。结果表明:该气道的流通性能很好但产生涡流的能力还可以进一步提高;在三维流动分析基础上提出了一系列的改进措施;对比各种改进措施下的模拟计算结果,发现在不减小流量系数的前提下,适当地增加螺旋腔室定义曲线相对气门凸台中心线的距离和增大涡壳角相结合的方法可以明显提高产生涡流的能力,是一种有效而又合理的改进办法。

With numerical simulation, an analysis is done on the three-dimension air flow in the helix intake port of a diesel engine. The anthors acquire the distribution of characteristic parameters of air in the port, such as velocity, pressure, turbulence kinetic energy, as well as the flow coefficient and rotate moment around the erect axes at the outlet. The results of simulation indicate that the negotiability of the port is very good while the ability of forming eddy can be enhanced, so several improve measures have been put forward. Comparing with simulation results of these measures, it finds out that the method of combining increase the distance between the definition curve of volute cavity and central line of valve protruding support as well as increase the eddy shell angle can obviously enhance the ability of forming eddy, which is an efficient and rational method.