圆转方内喷管换热特性

为了解圆转方内喷管再生冷却的换热特性,采用数值模拟的方法,分别对内喷管燃气、壁面和冷却液建立不同的控制方程,进行流动和传热的耦合计算,得到了内喷管和冷却液的流场和温度场。计算结果表明:转方之后的扩张段,如果型面不连续,间断点之后出现压缩波,波后壁面的温度和热流密度出现峰值,成为另一个危险截面;而且不连续壁面的温度高于光滑壁面的温度,使扩张段圆周方向壁面温度分布不均匀,造成热应力的不均匀;冷却肋和高导热系数的锆铜加强了冷却通道的换热,使冷却肋附近的气壁温度低于冷却通道底部气壁的温度。

Heat transfer characteristics in round to square nozzle

To understand heat transfer characteristics of regenerative cooling in round to square nozzle (RS nozzle), numerical simulation was employed. Governing equations for hot gas, solid wall and coolant were established respectively, and coupled calculation of flow and heat transfer was carried out. Flowfield and temperature field in RS nozzle were obtained. Results showed: (1)In divergent segment after transforming to square, if contour was not smooth, there would be a compression wave, which raised temperature and heat flux in gas wall and made this place become a dangerous segment. (2)Temperature in unsmooth wall was higher than that in smooth wall, which made temperature distribution along circumference un-uniform. (3)Ribs and highly conductive copper alloy strengthened heat transfer in cooling channel, and made temperature near rib lower than that near cooling channel bottom.