高湍流度对平板边界层传的热影响

INFLUENCE OF HIGH TURBULENCE ON PLATE HEAT TRANSFER

在雷诺数为１０６—１０７之间对０．１％—２５％湍流度的自由来流流过平板边界层传热问题进行了实验与数值研究。实验是在吸入式风洞内进行，用自由来流冷却加热平板，自由来流的湍流度可高达３０％。计算模型针对二维定常流，采用代数应力（热流）湍流模型，用ＳＩＭＰＬＥ算法进行计算。结果表明：高湍流度自由来流可使平板的平均Ｓｔａｎｔｏｎ数增加８５％。

Heat transfer of high turbulent flow over a flat plate was investigated experimentally and analytically under the conditions of the mainstream Reynolds numbers based on the plate length from 10 6 to 10 7 and mainstream turbulence intensity from 0 1% to 25%.The experiments were made in an indraft wind tunnel.The free mainstream cooled the heated copper plate.Two types of turbulence generators located upstream were used to generate different turbulence intensities high to 3%.ASM (Algebraic Stress Model) with heat flux,i.e. a developed K-ε model for 2-D steady flow was used in numerical simulation.The numerical results were compared with the experimental data in a good agreement.It is shown that the high intensity of turbulence can enhance heat transfer.The Stanton number at high turbulence intensity (10%) is approximately 85% higher than that at low turbulence intensity (1 7%).