理查德森数对多孔介质T型管道近壁面处流动与传热的影响

对多孔介质T型方管内冷热流体混合过程的流动和热传递进行大涡模拟，获得了近壁面处湍流混合的瞬时速度和温度，分析了3种理查德森数（Ri=-0.517，-0.093，0.517）对流动与传热的影响。数值结果表明：无论理查德森数Ri为正或负，在热流体区，多孔介质骨架温度较低，而在冷流体区，多孔介质骨架温度较高，说明热量从高温流体通过多孔介质向低温流体传递；最大温度波动发生在近壁面处的上部；由于多孔介质的湍动增强作用，减弱了浮升力对流动的影响，不同理查德森数对流动和传热的影响不够明显。

Effect of Richardson number on the flow and heat transfer near the wall in a T-junction with porous media

Large-eddy simulation(LES) has been employed to simulate the mixing of hot and cold fluids in a T-junction packed with porous media.The velocity and temperature of the turbulent mixing are obtained near the wall.The influences of different Richardson numbers(Ri=-0.517,-0.093,and 0.517) on the flow and heat transfer have been analyzed.The numerical results show that for both positive or negative Richardson numbers,the temperature of the solid skeleton is lower than that of the fluid in the hot fluid zone while it is higher than that of the fluid in the cold fluid zone,which indicates that heat is transferred from hot fluid to cold fluid through the solid skeleton.The maximum temperature fluctuation occurs near the top wall in the near-wall plane.The influence of the Richardson number on the flow and heat transfer in the T-junction is not obvious,due to the enhancement of turbulence in porous media.