纳米流体在散热器管中的传热模拟

Heat transfer simulation of nanofluids in car radiator tube

为研究纳米流体在汽车散热器中的传热能力,利用Pro/E和Hyper Mesh建立散热器扁平管的三维网格模型,再将其导入Fluent中,建立纳米流体在散热器管中的传热模型,以γ-Al_2O_3-EG纳米冷却液为研究对象,仿真模拟γ-Al_2O_3-EG在散热器管道中的传热状况,得到管道的温度分布,并结合数值计算获得纳米流体的性能参数及其变化趋势,研究纳米粒子对基液冷却性能的影响规律。结果表明:γ-Al_2O_3-EG纳米流体的最大雷诺数为1 237,在管道中层流流动;随着纳米粒子体积分数φ的增加,热流量Q先增大后减小,最大值为639.36 W;初始温度显著影响着纳米流体的传热系数h,当φ=1 vol%时,h40=h60×39.44%;体积流量fv由5 L/min增大至10 L/min时,努塞尔数Nu有最大增幅30.54%。

In order to study the heat transfer capability of metal oxide nano fluids in car radiators,the 3 D grid model of radiator flat tube was constructed by using Pro/E and Hyper Mesh. The mesh data were imported into Fluent and the heat transfer model of nanofluids in radiator tube was built.The heat transfer of γ-Al2O3-EG nano coolant in radiator tube was simulated and the temperature distribution of the tube was obtained. The performance parameters and the changing trend of nano fluids were obtained by numerical calculation,and the influence of nano particles on the cooling performance of base liquid was verified. The results show that the maximum Reynolds number ofγ-Al2O3-EG nano fluid is 1 237,which is the laminar flow in tube. With the increase of the volume concentration φ,the heat flow rate Q increases firstly and then decreases,and the highest value is639. 36 W. The inlet temperature significantly affects the heat transfer coefficient（ h） of nano fluids.When the φ = 1 vol%,h40/h60= 39. 44% and the flow rate fvincreases from 5 L/min to 10 L/min,the maximum increment of Nusselt number is 30. 54%.