涡轮集气腔出流流量分配和温度特性研究

采用模型实验和数值方法,针对特定的涡轮集气腔结构进行了出流特性研究。首先,在实验室条件下,进行全尺寸基准涡轮集气腔的模型实验研究并验证数值模拟方法；其次,在接近发动机真实气-热参数条件下进行系列的数值模拟,分析进出口压比、腔室高度、出流孔孔径和出流孔轴向位置等对出流孔流量分配和温度分布的影响。研究表明,除了集气腔出流流量分配的不均匀性之外,气流与热壁面之间的对流换热也导致明显的出流温度不均匀性；改变出流孔轴向位置距离、增加集气腔腔室高度是在不影响集气腔通流能力下改善出流均匀性的有效技术措施,当出流孔轴向偏置距离或集气腔腔室高度达到一定值后,其对改善出流流量分配均匀性的作用趋于微弱,但对于改善出流温度分布均匀性依然有较好的作用。

Mass-Flow Distribution and Temperature Characteristics of Outflow from Turbine Plenum Chamber

To illustrate the outflow characteristics of turbine plenum chamber, an investigation was performed for a specific configuration, by using model experiment and numerical approach. Firstly, a full-scale baseline model test was conducted under the laboratory conditions and the numerical method was validated. Then a series of numerical simulations were conducted under the engine representative aero-thermal conditions, wherein the effects of pressure ratio, cavity height, outlet diameter and axial-offset distance on the mass-flow distribution and temperature distribution of outflows. The results indicate that the non-uniformity of temperature distribution is also an obvious inherence in the turbine plenum chamber due to the convective heat transfer from the hot wall, except for the non-uniformity of mass-flow distribution. In general, altering the outlet axial-offset distance and increasing the cavity height are effective means to modify the uniformity of outflows without presenting any influence on the throughout flow capacity of turbine plenum chamber. It is noted that when the outlet axial-offset distance or cavity height reaches up to a certain value, their roles are weakly demonstrated on modifying the uniformity of mass-flow distribution, but still well behaved on modifying the uniformity of temperature distribution of outflows.