平板和静叶表面气流-水膜耦合流动特性的数值研究

发布时间：2018-03-02 19:02

本文选题：气流　切入点：水膜　出处：《西安交通大学学报》2016年11期 　论文类型：期刊论文

【摘要】：针对平板表面的空气水膜和透平静叶栅中的水蒸气水膜耦合流动特性提出了分析气流与壁面水膜耦合作用的数值方法,即气相主流和液相水膜视为相对独立的开口系,通过在两相各自的控制方程中添加考虑相间动量和能量交换的源项,实现水膜和气流的双向耦合计算。研究表明:平板表面水膜厚度和进口水膜雷诺数近似呈1/2指数幂关系,与来流马赫数呈反比关系,与出口背压呈弱负指数次幂关系;水膜流速与出口背压近似呈线性关系;水膜附加损失对水膜流量的变化较为敏感,对来流马赫数并不敏感;透平静叶压力面侧水膜厚度分布较为均匀,在叶顶角区的叶片表面出现水膜聚积,吸力面侧水膜厚度变化较为剧烈,在叶顶和叶根角区的叶片表面出现水膜聚积。从而得出影响透平叶栅通道中水膜分布的机理是,壁面曲率通过影响相间剪切力来影响壁面水膜厚度和速度的分布,端壁上从压力面到吸力面的二次流引起水膜向吸力面侧聚积,通道涡和角涡引起的径向压力梯度导致叶片表面水膜沿叶高重新分布,水膜聚积对叶片表面的压力分布和出口气流角产生显著影响。
[Abstract]:In this paper, a numerical method for analyzing the interaction between air flow and wall water film is proposed to analyze the coupled flow characteristics of the air-water film on the flat surface and the vapor water film in the permeable cascade, that is, the gas-phase mainstream and the liquid water film are regarded as relatively independent open systems. The bidirectional coupling calculation of water film and gas flow is realized by adding a source term that considers the exchange of momentum and energy between the two phases. The results show that the thickness of water film and the Reynolds number of inlet water film on the surface of the plate are approximately 1/2 exponential power relations. It is inversely proportional to the inflow Mach number and weakly negative exponential power relation to the outlet back pressure, the water film velocity is approximately linear with the outlet back pressure, the additional loss of water film is sensitive to the change of water film flow rate, and it is not sensitive to the flow Mach number. The thickness distribution of water film on the pressure surface of the permeable leaf is more uniform, the water film accumulation occurs on the blade surface in the apical corner area, and the thickness of the water film on the suction surface side changes sharply. The water film accumulation occurs on the blade surface in the tip and root angle region, and the mechanism influencing the water film distribution in the turbine cascade channel is that the wall curvature affects the distribution of the water film thickness and velocity through the influence of the interphase shear force. The secondary flow from the pressure surface to the suction surface on the end wall leads to the accumulation of water film to the suction surface, and the radial pressure gradient caused by channel vortex and angular vortex causes the water film on the blade surface to be redistributed along the blade height. Water film accumulation has a significant effect on the pressure distribution and outlet flow angle on the blade surface.
【作者单位】：西安交通大学能源与动力工程学院;中国航发商用发动机有限责任公司;
【分类号】：TK14

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