旋流片内插缩放板的强化传热数值模拟

对旋流片插入平行缩放板的传热与流阻性能进行了数值模拟研究．结束表明：旋流片产生的螺旋流能够减薄边界层，增加流体的湍流度，从而进行强化传热．在19000〈RP〈36000时，局部努赛尔数和阻力系数都沿着流体流动方向减小，而局部综合传热因子的变化趋势是先增大而后降低．数值模拟结果还表明，与空的平板相比，在缩放板内插旋流片流道中速度与温度梯度夹角的余弦值变大，速度场和温度场的协同程度有所增大．

NUMERICAL SIMULATION OF HEAT TRANSFER ENHANCEMENT OF CONVERGING-DIVERGING PLATE WITH SPACED TWISTED-TAPE

Heat transfer and flow characteristics of the converging-diverging plate with spaced twisted-tapes have been obtained by numerical simulation.Swirl flow is produced by spaced twisted-tapes which can reduce thickness of boundary layer,and increase the turbulent intensity for enhancing the heat transfer rate.The local Nusselt number and local friction factor decrease along the main flow direction for the range of Re from 19 000 to 36 000.And the heat transfer efficiency indexes increase firstly and decrease later along the main flow direction.The numerical results indicate that the cosine of the angle of velocity and gradient of temperature for converging-diverging plate inserted with spaced twisted-tape increases,compared to the smooth plate.Synergy between velocity and temperature fields in the converging-diverging plate with twisted-tapes can improve.