分形小通道换热器内湍流与换热特性数值模拟

发布时间：2018-08-29 11:34

【摘要】：建立树状分形换热器通道内湍流流动和传热的三维模型,采用流、固耦合计算方法对入口水力直径为3.2 mm的矩形截面树状通道内流动与换热进行了数值模拟,获得了湍流状态下分形结构换热器内流体速度和温度分布、压力损失及换热器表面最大温差。在相同工况下,应用尼古拉兹半经验公式对通道内压损进行了理论验证。计算结果表明:分形树状通道结构在湍流状态下形成若干回流使其具有较强换热能力和较均匀温度分布,其换热器表面温差随入口雷诺数增大而减少,流体入口温度对换热器表面温差影响很小;随着入口雷诺数增大通道内压损是增加的,并且数值模拟结果与理论分析结果比较接近,说明采用文中数值模拟方法获得的结果准确可靠。
[Abstract]:A three-dimensional model of turbulent flow and heat transfer in a tree-shaped fractal heat exchanger channel is established. The numerical simulation of flow and heat transfer in a tree-shaped channel with an inlet hydraulic diameter of 3.2 mm is carried out by using the fluid-solid coupling method. The fluid velocity and temperature distribution, pressure loss and maximum temperature difference of the surface of the heat exchanger with fractal structure are obtained in turbulent state. Under the same working conditions, the pressure loss in the channel is theoretically verified by using the Nikolaz semi-empirical formula. The calculation results show that the fractal tree channel structure has strong heat transfer ability and uniform temperature distribution due to the formation of some reflux in turbulent state, and the surface temperature difference of the heat exchanger decreases with the increase of inlet Reynolds number. The fluid inlet temperature has little effect on the surface temperature difference of the heat exchanger, and the pressure loss in the channel increases with the increase of the inlet Reynolds number, and the numerical simulation results are close to the theoretical analysis results. The results obtained by numerical simulation in this paper are accurate and reliable.
【作者单位】：景德镇陶瓷大学;英业达集团;
【分类号】：TQ051.5

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