横向侧边射流强化平板对流换热试验研究OA

To investigate the mechanism of convective heat transfer enhancement of downstream flat plate by lateral jet in crossflow,an experimental setup was established.Temperature distributions and local convective heat transfer coefficients of the downstream flat plate were measured under varying Reynolds numbers(Re=5×10³～1×104)and jet-to-crossflow velocity ratios(r=0～8.92).Results indicate that at low jet-to-crossflow velocity ratios(e.g.r=0.57),the introduction of a lateral jet in crossflow slightly deteriorates the convective heat transfer performance of the downstream flat plate.However,as r increases,the convective heat transfer enhancement progressively improves,exhibiting an optimal jet-to-crossflow velocity ratio for maximum heat transfer augmentation.Further increasingrleads to gradual degradation of the enhancement.Within the studied Rerange of Rein the paper,the optimal performance is achieved atr=6.69,where the convective heat transfer coefficient of the downstream flat plate increases by over 50%.Combined theoretical analysis and numerical simulations reveal,the enhancement mechanism primarily originates from the lateral jets'promotion of fluid turbulence and formation of turbulent coherent structures,disrupt the thermal boundary layer of the heat transfer plate.When the central trajectory and spread width of the lateral jet cover the downstream flat plate,the fluid flow over the flat plate is compressed,forcing it closer to the heat transfer surface and thereby enhancing heat transfer.