带冠空心冷却叶片的三维应力分析

 带冠的高温空心冷却叶片,由于它的形状复杂,工作时所承受的离心力大,温度高,气动力分布极不均匀,因此到目前为止,尚未见有准确可靠的计算方法,一般只能靠实验或统计的方法来对付生产使用中出现的问题。 为试图解决此一问题,我们采用高阶的三维等参元素来离散复杂的叶片形状。用节省内存空间而精度又高的波前法来求解此特大型方程组。用高阶双三次Coons样条插值函数来拟合叶型的空间曲面。为验证本方法和程序的可靠性,计算了各种例题,做了真实叶片的高速旋转实验,它们都证明了本方法的可靠性和计算精度是满意的。 本方法的适应性也较强,用它可以计算实心和空心的、带冠和不带冠的、伸根和非伸根的、高温和常温的各种类型叶片。

THREE-DIMENSIONAL STRESS ANALYSIS FOR A SHROUDED AIR-COOLED TURBINE BLADE

Up to now, there are still no accurate and reliable methods for computing the stress field of a shrouded air-cooled turbine blade, because the cooled blade with a complex configuration works under high temperatures and great centrifugal loads, moreover, the distribution of aerodynamic loads is rather non-uniform. Usually, such problems occured in practice are tackled by means of experiments or statistics.In attempt to solve these problems, we applied the high order 3-dimensio-nal isoparametric elements for describing the complex configuration of blades. In order to solve the high order linear system of equations, we have used the frontal method with high accuracy and considerable economy of main memory space. The bicubic Coons interpolation function is also used to fit the space curved surface. For the sake of verifying the present method and the reliability of the given program, we have compared the results of numerical computations with those obtained from experiments on the revolution of the real blades at high speeds, and the comparison confirms the adaptability and the satisfactory accuracy of the present method.This method is available to various blades, such as solid or hollow blades; blades shrouded or unshrouded; blades with or without a shank root; and at high or normal temperatures.