正弦波纹微通道内单相流动及换热特性数值研究

Numerical Study on Single-phase Flow and Heat Transfer Characteristics in Sinusoidal Wavy Microchannels

为了分析正弦波纹微通道中的单向流动和对流换热特性,通过数值模拟研究了波幅为125~500μm范围的正弦波纹微通道中,入口雷诺数Re在100~1 000条件下冷却液的流动和换热特性。研究结果表明:波幅和雷诺数的增加均会导致流动压降和摩擦因子增加。当Re=400、波幅A从125μm增加至500μm时,流动压降和摩擦因子分别升高至原始值的3倍和2倍,从而显著增加了流动阻力,表明波幅增强了流道内部的流动和扰动,提高了换热效率;当波幅A=500μm、雷诺数Re由100增加至1 000时,压降增大约50倍,摩擦因子增大约10倍,传热系数增大5倍,表明随着雷诺数的增加,流道内冷却剂的流速和摩擦因子也随之增加,流动扰动性越强,传热系数也越高。

In order to analyze the single-phase flow and convective heat transfer characteristics in sinu-soidal wavy microchannels,numerical simulations were conducted to investigate the fluid flow and heat transfer characteristics of the coolant in sinusoidal wavy microchannels with wave amplitudes ranging from 125 to 500μm,under inlet Reynolds numbers of 100 to 1000.The research results indicate that an in-crease of wave amplitude and Reynolds number leads to an increase of flow pressure drop and friction fac-tor.Under the conditions of inlet Reynolds number Re of 400 and wave amplitude A from 125 to 500μm,the flow pressure drop and friction factor increase to 3 and 2 times of the original values,re-spectively,significantly increasing the flow resistance.The larger wave amplitude enhances the flow and disturbance inside the flow channel,improving heat transfer efficiency;when the wave amplitude is 500μm and Reynolds number increases from 100 to 1000,the pressure drop,friction factor and the heat transfer coefficient increase by 50,10 and 5 times respectively.With the increase of Reynolds number,the flow velocity and friction factor of the coolant in the flow channel also increase.The stronger the flow disturbance,the higher the heat transfer coefficient.