Dynamic simulation of nozzle structure based on thermal-fluid-solid coupling analysis

Abstract

Many engineering structures are subjected to the combined action of thermal field, flow field and vibration load during use. The mechanical analysis of this kind of structure has important theoretical significance and engineering practical value. However, due to the complexity of multi-field coupling, it is difficult to analyze dynamic response and dynamic strength. A method to simplify the thermal-fluid-solid coupling model for specific engineering issues was proposed aiming at modeling the actual situation in which the high temperature field of the engine nozzle structure is relatively stable. Heated grid reconstruction, thermal modal analysis technology, and fluid-structure coupling response calculation method based on modal superposition were taken to obtain the load distribution and dynamic response level of the engine nozzle structure under the condition of thermal-fluid-solid coupling, which created conditions for structural dynamic strength evaluation including the prediction of vibration fatigue life. The test structure of an engine nozzle was taken as an example to perform dynamic response calculation and fatigue life prediction under thermal fluid-solid coupling conditions. Then the location of weak parts of the structure was identified, and effective suggestions for design improvement was put forward. Compared with the actual test results, the feasibility and accuracy of the method are preliminarily verified.