多分流叶栅S_1旋成流面上的气动正命题有限元新解法及试验研究

分流叶栅或串列叶栅的流场计算和试验研究是透平机械S_1流面问題中的一个重要课题。但求解分流叶栅或串列叶栅的气动正命题是比较困难的,主要在于确定准确的出气角和绕分流叶片的环量值或者分流比。本文在用有限元素法求解多分流叶栅或串列叶栅S_1任意旋成流面上的气动正命题时,把绕叶片的环量位作为无节点的自变量进行直接求解,而不是把它作为一个强加边界条件来处理,从而避免了以前为使叶片尾缘满足广义库塔条件所需的迭代过程。计算与实验结果吻合良好。本文还用自编的程序对多分流叶柵进行了多方案的计算,提出了一种气动性能较好的汽轮机高压隔板多分流叶栅设计,并对这种多分流叶栅和带不同加强筋的叶栅进行了静吹风试验,试验结果表明,这种多分流叶栅比原来带加强筋叶栅的流动损失明显下降。

A New Finite Element Solution for the Aerodynamic Direct Problem on S_1 Stream Sheet of Revolution in Cascade with Multi-splitter Vanes and Experimental Research

In solving the aerodynamic direct problem of flow on an arbitrary S_1 surface of revolution through a turbomachinery blade row with many splitter vanes, the circulation around blade is used as a nodeless independent variable and is directly computed in the numerical solution instead of as a condition imposed by means of finite-element method. Thus the iterative process for satisfying the generalized K-J condition at the trailing edges of the blades is avoided. The results calculated are with compared experimental measurements, and their agreement is satisfactory.In this paper, the flow in different cascades with splitter vanes is calculated using the program compiled by us, and a cascade of better aerodynamic performance with splitter vanes is presented for high pressure diaphragms in a steam turbine. The tunnel tests are performed on the cascades with splitter vanes and with different ribs. The experimental results illustrate that the flow losses in the cascade with splitter vanes are a lot lower than those in the cascades with ribs.