离散叉排肋化内冷通道流动与传热的数值模拟

运用数值模拟方法,计算肋片导流角θ为15°～45°的离散叉排肋化冷却通道在雷诺数介于1×104～20×104之间时的换热和流阻特性。研究结果表明,(1)各算例的强化换热能力随雷诺数的增大而减小,流动阻力随雷诺数的增大而增大,综合换热效率随雷诺数的增大而减小。(2)肋片导流角的改变可以显著改变通道的换热和流阻特性。相同雷诺数下,θ=45°的强化换热比和通道阻力增大比最高,θ=15°的强化换热比和通道阻力增大比最低。在研究范围内θ=15°的综合换热效率最好。

NUMERICAL SIMULATION ON TURBULENT FLOW AND HEAT TRANSFER IN COOLING DUCT WITH DISCRETE-CROSS RIBS ON THE OPPOSITE WALLS

Numerical simulation was conducted to investigate the turbulent flow and heat tr ansfer in a cooling duct with discrete-cross ribs on two opposite walls at Reyn olds number of 1×104 to 20×104.Seven cases with different angles between ribs and flow direction were calculated:θ=15° to 45°.Results show that:(1) The averaged Nusselt number decreases as the cooling inlet Reynolds number inc reases.At the meantime,the friction factor increases significantly and the compr ehensive heat transfer efficiency gets lower.(2) The characteristics of heat tra nsfer and turbulent flow are evidently effected by angles between ribs and flow direction.At the same Reynolds number,the case of θ=45° has the maximum av eraged Nusselt number ratio and friction factor ratio while the case of θ=1 5° has the minimum one.Take one to another,the case of θ=15° has the best comprehensive heat transfer efficiency.