钨渗铜喉衬复合结构喷管热-结构耦合分析

Thermal structural coupling analysis of composite nozzle with copper infiltrated tungsten-lined throat

为研究某复合结构喷管的传热特性,并计算喷管工作过程中喉衬受到的热应力,针对某型发动机钨渗铜喉衬复合结构喷管,建立了喷管内流场与结构耦合的三维计算模型,采用计算流体动力学软件Fluent对复合结构喷管的稳态流场和传热过程行了数值仿真,得到了喷管的流动参数和固体域温度场计算结果。采用单向流固耦合计算方法,分析了钨渗铜喉衬在不同时刻下的热应力。分析结果表明,喷管固体域温度随时间推进逐渐升高,隔热层最高温度出现在入口等直段,达到约2800 K,喉衬最高温度出现在喉部,达到约2100 K,温度变化率在固体域材料交界面处出现明显间断;喉衬的热应力随温度升高而增大,背壁出现两个明显的压力峰值,大小约为135 MPa和90 MPa;最大应力出现在喷管内壁面喉部附近,大小约为155 MPa。

In order to study the heat transfer characteristics of a composite structure nozzle and calculate the thermal stress on the throat insert during the working process of the nozzle,a three-dimensional calculation model for coupling the internal flow field and the structure in the nozzle was established for a W-Cu alloy insert structure nozzle.The steady-state flow field and heat transfer process of the composite structure nozzle were numerically simulated by means of the computational fluid dynamics software FLUENT,and the flow parameters of nozzle and the calculation results of solid temperature field were obtained.The thermal stress of W-Cu alloy throat insert at different times was analyzed by using the unidirectional fluid-solid coupling calculation method.The results show that the temperature in the solid region of the nozzle increases gradually with time.The maximum temperature of the thermal insulation layer appears in the straight section of the inlet,up to 2800 K;the maximum temperature of the throat insert appears in the throat,reaching about 2100 K,and the temperature change rate appears obvious discontinuity at the interface of the materials in the solid region.The thermal stress of throat insert increases with the increase of temperature,and two obvious pressure peaks occur on the back wall,about 135 MPa and 90 MPa;the maximum stress appears near the throat of the inner wall of the nozzle,about 155 MPa.