透平叶片在流-热-固耦合场下的变形研究

透平叶片在复杂耦合场下工作会产生形变,与设计流道曲面产生偏差,严重影响涡轮机的工作效率。基于流-热-固耦合有限元模型对复杂工况下叶片的变形进行了研究。采用RNGk-e湍流模型经FLUENT流场仿真实现叶片的三维温度场和压力场模拟,利用ANSYS分析得到叶片在温度、压力、离心力单独作用和耦合作用下对应的变形量,并运用灰色关联度理论分析变形之间的关系。通过分析发现,耦合场下的叶片变形并不是各载荷单独作用下变形的线性叠加,而是复杂地耦合;温度是影响叶片变形的优势子因素,压力和离心力的影响较小。分析结果对叶片形变控制策略、补偿及重构都具有重大指导价值。

Analysis of turbine blade deformation under fliud-heat-solid coupling field

Turbine blades working in the complex coupling fields may cause deformation, as well as the surface bias from the design demand, which seriously affecting the efficiency of the turbine. In order to analyze the blade deformation under complex working conditions, a fluid-heat-solid coupling finite element model was established to simulate the three dimensional flow fields. Based on the numerical simulation, blade surface temperature and pressure was obtained. The temperature and pressure were applied to the turbine blade, and the deformation was calculated from the effect of the single load or in combination. Finally, the deformation in each direction with single load and coupled ones were analyzed according to the grey correlation theory. The data show that the deformations are not simply linear overlay but complicatedly coupled; temperature is the main factor which outweighs the pressure and centrifugal force. The present results in this work are useful for the blade deformation control strategy, compensation and reconstruction of blade, which have great theoretical significance and engineering values.