Measurement of interstitial convective heat transfer and frictional drag for flow across metal foams
Measurement of interstitial convective heat transfer and frictional drag for flow across metal foams
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DOI：
10.1115/1.1416690
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发表时间：
2002-02-01
影响因子：
--
通讯作者：
Chao, CH
中科院分区：
文献类型：
--
作者：
Hwang, JJ;Hwang, GJ;Chao, CH
对泡沫铝管内的对流换热和摩擦阻力进行了实验研究。考察了泡沫孔隙率（ε = 0.7，0.8和0.95）和流动雷诺数（1900 ≤ Reless ≤ 7800）的综合影响。泡沫铝的流动阻力由测压孔测量，而泡沫铝中的间隙传热系数是使用瞬态单吹技术与热非平衡两方程模型确定的。进一步测量固体材料的温度分布，以双重检查传热结果。为了了解摩擦阻力机制，在泡沫铝管道中进行了烟丝流动显示。结果表明，在一定的雷诺数下，随着泡沫孔隙率的减小，摩擦系数和体积换热系数均增大。此外，在相同的泵浦功率约束下，在所研究的三种泡沫铝中，η =0.8的泡沫铝具有最好的热性能。最后，孔隙努塞尔数的经验关联式开发在不同的泡沫孔隙率下的孔隙雷诺数。
Convective heat transfer and friction drag in a duct inserted with aluminum foams have been studied experimentally,. The combined effects of foam porosity (epsilon =0.7, 0.8, and 0.95) and flow Reynolds number (1900less than or equal toReless than or equal to7800) are examined. Frictional drags for flow across the aluminum foam are measured by, pressure taps, while interstitial heat transfer coefficients in the aluminum foam are determined using a transient single-blow technique with a thermal non-equilibrium two-equation model. Solid material temperature distribution is further measured for double check of the heat transfer results. To understand the frictional drag mechanisms, smoke-wire flow visualization is conducted in the aluminum foam ducts. Results show that both the friction factor and the volumetric heat transfer coefficient increase with decreasing the foam porosity at a fixed Reynolds number. In addition, the aluminum foam of epsilon=0.8 has the best thermal performance under the same pumping power constraint among the three aluminum foams investigated. Finally, empirical correlations for pore Nusselt number are developed in terms of pore Reynolds number under various foam porosities.