Laminar Dissipative Flow in a Porous Channel Bounded by Isothermal Parallel Plates
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摘要: 利用Darcy模型,研究了平行板间充填饱和多孔介质的通道中,在热量入口处传热的粘性耗散效应.讨论了等温边界情况.求得热量入口处局部温度和体积计算平均温度随Nusselt数的分布.给出了独立于Brimkman数的经充分发展的Nusselt数应为6A·D2并观察到,若忽略粘性耗散影响,将导致熟知的内流现象,此时Nusselt数等于4.93.还给出了有限差分数值解.结果表明解析法和数值法的结果吻合很好.Abstract: The effects of viscous dissipation on thermal entrance heat transfer in a parallel plate channel filled with a saturated porous medium, is investigated analytically on the basis of a Darcy model. The case of isothermal boundary is treated. The local and the bulk temperature distribution along with the Nusselt number in the thermal entrance region were found. The fully developed Nusselt number, independent of the Brinkman number, is found to be 6. It is observed that neglecting the effects of viscous dissipation would lead to the wellknown case of internal flows, with Nusselt number equal to 4.93. A finite difference numerical solution is also utilized. It is seen that the results of these two methods-analytical and numerical are in good agreement.
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Key words:
- heat transfer /
- Nusselt number /
- forced convection /
- porous media /
- viscous dissipation
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[1] Nield D A,Bejan A.Convection in Porous Media[M].2nd ed.New York:Springer,1999. [2] Nield D A,Kuznetsov A V,Xiong M.Thermally developing forced convection in a porous medium:parallel plate channel or circular tube with walls at constant temperature[J].J Prous Media,2004,7(1):19—27. doi: 10.1615/JPorMedia.v7.i1.30 [3] Nield D A,Kuznetsov A V,Xiong M.Thermally developing forced convection in a porous medium:parallel plate channel or circular tube with walls at constant heat flux[J].J Porous Media,2003,6(3):203—212. doi: 10.1615/JPorMedia.v6.i3.50 [4] Nield D A,Kuznetsov A V,Xiong M.Effect of local thermal non-equilibrium on thermally developing forced convection in a porous medium[J].Int J Heat Mass Transfer,2002,45(25):4949—4955. doi: 10.1016/S0017-9310(02)00203-X [5] Lahjomri J,Oubarra A,Alemany A.Heat trasfer by laminar Hartmann flow in thermal entrance region with a step change in wall temperature:the Graetz problem extended[J].Int J Heat Mass Transfer,2002,45(5):1127—1148. doi: 10.1016/S0017-9310(01)00205-8 [6] Lahjomri J,Oubarra A.Analytical solution of the Graetz problem with axial conduction[J].ASME J Heat Transfer,1999,121(4):1078—1083. doi: 10.1115/1.2826060 [7] Narasimhan A,Lage J L.Modified Hazen-Dupuit-Darcy model for forced convection of a fluid with temperature dependent viscosity[J].ASME J Heat Transfer,2001,123(1):31—38. doi: 10.1115/1.1332778 [8] Kreyszig E.Advanced Engineering Mathematics[M].4th Ed.New York:John Wiley & Sons,1979. [9] Shah R K,London A L.Laminar Flow Forced Convection in Ducts(Advances in Heat Transfer,Supplement 1)[M].New York:Academic Press,1978. [10] Tannehill J C,Anderson D A,Pletcher R H.Computational Fluid Mechanics and Heat Transfer[M].2nd Ed.Bristol:Taylor & Francis,Inc,1997. [11] Nield D A,Kuznetsov A V.Effect of heterorgeneity in forced convection in a porous medium:parallel plate channel or circular duct[J].Int J Heat Mass Transfer,2000,43(22):4119—4134. doi: 10.1016/S0017-9310(00)00025-9
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