扇形凹穴型微通道液体流动与传热特性的数值模拟

Numerical simulation of fluid flow and heat transfer in a microchannel with fan-shaped reentrant cavities

为得到扇形凹穴型微通道内单相液体流动与传热特性,以等截面矩形微通道为参照,利用FLUENT计算流体力学模拟与分析软件进行三维数值模拟,采用有限体积法离散模型和SIMPLEX算法进行层流计算,讨论扇形凹穴型微通道热沉在不同体积流量不同热流密度条件下流体流动特性和传热特性.模拟结果表明:较大Re条件下扇形凹穴型微通道具有很好的流体流动特性和传热特性,其流动与传热机理可归结为边界层的破坏、喷射节流效应及层流滞止区的相互作用.

To examine the fluid flow and heat transfer characteristics in a microchannel with fan-shaped reentrant cavities,the numerical investigations were conducted,and the results were compared with the conventional rectangular microchannel data.The SIMPLEX method was used for the computation.The effects of volumetric flow rate,heat flux on the pressure drop and thermal resistance were investigated in detail.The numerical simulation results indicate that a microchannel with fan-shaped reentrant cavities can improve heat transfer performance with an acceptable pressure drop when the Reynolds numbers are larger,and the fluid flow and heat transfer mechanism can be attributed to the interaction of the redeveloping of hydraulic and thermal boundary layers,the effect of jet and throttling and the stagnation zone of laminar flow.