喷管分离流流动-热-结构顺序耦合数值模拟及试验研究

Aiming at the complex loads on the nozzle under the flow separation state of a large expansion ratio nozzle, the nozzle structure is analyzed using a numerical method. The second-order upwind interpolation scheme of finite volume and the SST eddy dissipation turbulence model are utilized, combined with a two-layer enhanced wall function, to solve the N - S equations and the heat conduction equation. A fluid - structure coupling flow and heat transfer model is adopted, where the flow field and the structure temperature field interact with each other as boundary conditions and exchange data, realizing the coupled numerical analysis of the flow field solution and the temperature field solution. The finite element method is applied to conduct a transient static analysis on the structure under a given temperature field and pressure loads, achieving the sequential coupling of flow - heat - structure. Using this calculation model, a numerical simulation is carried out on an axisymmetric Laval nozzle. It is found that under a large expansion ratio, flow separation occurs in the nozzle, and after the oblique shock wave at the separation point, the gas temperature gradient and pressure...

针对大膨胀比喷管气流分离状态下喷管所受的复杂载荷,采用数值方法分析喷管结构。利用有限体积二阶迎风插值格式及SST涡耗散湍流模型,结合二层增强型壁面函数,求解N-S方程、热传导方程。采用流固耦合的流动与换热模型,流场与结构温度场互为边界条件交互数据,实现了流场解算与温度场解算的耦合数值分析。应用有限元方法对给定的温度场及压力载荷作用下的结构进行了瞬态静力分析,实现了流动-热-结构的顺序耦合。采用此计算模型对轴对称拉瓦尔喷管进行了数值模拟,发现在大膨胀比下喷管发生气流分离,经分离处的斜激波后气流温度梯度及压力