基于流-固耦合的测量耙设计

Measuring Rake Design Based on Fluid-Structure Interaction

在设计某型涡扇发动机外涵出口测量耙时,发现原有的强度计算方法中载荷施加方法与实际发动机流场受力条件相差较大,无法模拟测量耙在发动机流道中所受的真实载荷。为解决上述问题,提出采用单向流-固耦合的方法开展该测量耙的静强度分析和模态特性分析。发现采用单向流-固耦合方法计算得到的测量耙载荷更加接近测量耙真实装机状态所受载荷。经过计算,与传统方法相比,采用单向流-固耦合方法得到的静应力由248.69 MPa减小为51.49 MPa,变形由0.81 mm减小为0.16 mm;测量耙前六阶固有频率均增长超过7%,成功避开了发动机转子固有频率。流-固耦合设计方法可以为提高现有的测量耙设计能力提供参考,同时应用于后续测量耙设计及校核计算中。

During the design of a turbofan engine measuring rake, it was found that the existing strength analysis method was quite different from the actual engine flow conditions, making it hard to simulate the real load on the rake in the engine runner. To solve the above problems, a unidirectional fluid-structure interaction method was proposed. It is found that the load calculated by the unidirectional fluid-structure interaction method is closer to the real installed load. Compared with the traditional method, static stress obtained by the coupling method is reduced from 248.69 MPa to 51.49 MPa, and deformation is reduced from 0.81 mm to 0.16 mm. The top six modals of the rake have increased by more than 7%, successfully avoiding the engine rotor natural frequency. The coupling design method can provide a reference for improving the existing measuring rake design capability, and it can be used in subsequent design and verification calculation of measuring rake.