结构参数对圆转矩形喷管换热的影响

Effects of structure parameters on heat transfer in round to rectangular nozzles

关键词:  液体火箭发动机  气动塞式喷管+  内喷管+  再生冷却  数值仿真

Key words:  Liquid propellant rocket engine  Plug nozzles  Internal nozzle~+  Regenerative cooling  Numerical simulation

摘要:

为了解结构参数对圆转矩形内喷管再生冷却换热的影响,设计了多个圆转矩形喷管,考虑了三种结构参数:转方位置、出口高宽比和出口圆角大小的影响。采用有限体积法求解三维可压缩的N-S方程对其内部流动和换热进行了数值模拟。湍流模型采用标准的k-ε双方程模型,壁面附近的流动和传热采用壁面函数法处理,速度与压力的耦合采用SIMPLE算法求解。结果表明:在型面一阶导数连续的情况下,转方位置对圆转矩形内喷管的换热影响不大;出口高宽比对圆转矩形内喷管的换热影响较大,出口高宽比不能太小,否则影响内喷管流场和换热;出口圆角大小影响内喷管周向上的温度分布,圆角太小造成周向温度分布不均匀。

Abstract:

To understand influence of structure parameters on heat transfer in round to rectangular nozzle(RR nozzle),several RR nozzles were designed.Three parameters were taken into consideration: round to rectangular transforming position,ratio of height to width and arc radius at exit.Three dimensional Navier-Stokes equations were solved with finite volume method.Standard k-ε turbulent model and wall function were used for near wall treatment.The coupling of pressure and velocity were realized with SIMPLE algorithm.Results indicate: under conditions that contour derivative is consecutive,transforming position does not significantly affect heat transfer in RR nozzles;height to width ratio at exit greatly influences heat transfer in RR nozzles and too small ratio would lead to high temperature points on gas side wall;arc radius has an effect on surface temperature of perimeter of gas side wall and too small radius makes circumferential temperature non-uniform.