车用射流换气系统的研究

为了减少大型客车空调系统换新风的能耗，提出了发动机抽吸式换新风的方法．并结合某款客车设计了一引射装置，分别就三种缩口口径（94，98，102mm）的引射装置建立模型，用标准的双方程模型模拟流场的湍流效应，在发动机不同转速下，分别就控制阀门全开和全关两种模式进行了三维定常流动的数值计算，并对计算结果进行了比较分析，得出了以下结论：1）该款客车若采用102mm缩口口径的方案，既能满足换新风的需求，又能减少其对发动机的不利影响；2）通过调整控制阀门的开度，能实现换新风量的调节．

Study on the Coach Ventilating System by Engine's Aspiration

In this paper the coach ventilating system by engine＇s aspiration for energy saving was introduced. An injection device was designed for a coach. Three models with different necking diameter （94mm, 98mm, 102mm） was set up to simulate the device. The turbulence flow effect of flow field was simulated using the standard k - ε model. The 3D steady numerical calculations were carried on in two modes （ fully open valve and fully closed valve） under several engine operating conditions respectively. Through comparing and analyzing the results it was concluded that the scheme of 102 mm necking diameter was suitable for the coach because it could meet the needs of ventilating and reduce the adverse effects of engine. Moreover the ventila- tion volume could be controlled by regulating the valve opening.