高焓高压空气加热器壁面传热过程数值计算

Numerical simulation of heat transfer process in the wall of a high enthalpy and pressure air heater

以一种高焓高压空气加热器为研究对象,对其冷却通道的流动和传热进行了三维数值仿真,冷却剂采用液态水,燃烧室和喷管分别采用不同的壁面材料,考虑壁面材料物性随温度的变化,并通过加热器热试验证了数值仿真结果的正确性。在此基础上,对比分析了气体辐射、冷却通道结构以及冷却水的流动方式对壁面换热的影响。结果表明:气体辐射对加热器燃烧室段壁面换热影响较大,对喷管壁面换热无明显的影响。在传热计算中,忽略气体辐射会引起较大的误差;冷却通道数和宽度存在最优组合,使得壁面换热量最大。冷却水的流动方式对燃气侧壁面温度影响较小,但对冷却液侧壁面温度的影响较大。

Three dimensional turbulent fluid flow and heat transfer in the cooling channels of high enthalpy and pressure air heater were numerically investigated. The liquid water was employed as the coolant, and the materials of eombustor and nozzle wall were steel and copper respectively, whose thermo physical properties vary with temperature. The hot-fire tests of the facility were performed to validate the simulation results. The influences of gaseous radiation, the channel configuration and cooling routing on the wall heat transfer were discussed and analyzed. The result shows that the heat transfer of combustor wall is affected obviously by the gaseous radiation which has little effect on the nozzle wall. The result will lead to significant error if the gas radiation is neglected. The heat transfer rate of wall is largest if the number and the width of channel was optimized. The flow mode of coolant has a great effect on the coolant side wall temperature but a little impact on the hot-gas side wall temperature.