层板内冷通道辐射换热影响

Thermal radiation effects in the Lamilloy interior cooling passage

分析了层板换热过程,使用了"去除复杂表面"和"无限大平板"等假设,给出了该假设下层板内腔辐射换热计算公式.又以一特定几何结构的层板模型为例,使用了3维流体力学计算程序求解了流-固耦合情况下的层板内部换热过程,研究了其在4种航空发动机典型工作状态下,内冷通道中的对流和辐射换热情况,得到了辐射与对流换热强度之比θ随冷气入口Re数和燃气加热功率的变化曲线,并对该曲线进行了指数拟合.建立了一套快速简捷计算层板内腔辐射状况的方法,为层板内腔换热研究是否应该忽略辐射,以及对层板冷却效果的修正,提供了一定的判断和计算依据.

The heat transfer process of the Lamilly was analyzed, and the formulas for describing the thermal radiation inside the Lamilloy were provided under the suppose of configuration simplifying, for example, the complex surface cutting off and the infinity plate supposition. The thermal radiation and convection heat transfer in interior cooling passage of the Lamilloy with a typical configuration was studied by the method of three dimensional fluid-solid coupled computation. The ratio of thermal radiative to convective heat flux θ was introduced and it was a function of the cooling air inlet Re number and the gas heating power. Analysis was carried out under 4 typical aero-engine working conditions, and correction was performed with exponential fit. A simple method was put forth to evaluate the effect of thermal radiation, and with this method, the importance of thermal radiation could be easily assessed.