Pulsating flow in a channel filled with a porous medium under local thermal non-equilibrium condition: an exact solution
Pulsating flow in a channel filled with a porous medium under local thermal non-equilibrium condition: an exact solution
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DOI：
10.1007/s10973-020-09843-0
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发表时间：
2020-06
影响因子：
4.4
通讯作者：
Arman Fathi-kelestani;M. Nazari;Y. Mahmoudi
中科院分区：
文献类型：
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作者：
Arman Fathi-kelestani;M. Nazari;Y. Mahmoudi
目前的工作分析研究了局部热非平衡条件下填充多孔介质的通道中脉动流的强制对流换热问题。考虑多孔介质中的内部生热，通道壁受到恒定热通量边界条件的影响。获得了多孔介质中流体和固相的速度、努塞尔数和温度分布的精确解。讨论了毕奥数、达西数、液固有效导热系数和普朗特数等相关参数的影响。所施加的压力梯度被认为是正弦波形。讨论了无量纲频率和压力幅值系数对系统速度场和温度场的影响。发现不同时间的非定常速度的一般形状与稳定数据非常相似。结果表明，随着毕奥数或导热系数的增加，液相和固相的非稳态温度幅度减小。对于大毕奥数，固相和液相的无量纲温度相似并且接近其稳定对应物。努塞尔数的结果表明，增加毕奥数或导热率会降低努塞尔数的幅度。固相内生热的增加对努塞尔数的振幅与平均值的比值没有显着影响，而液相内生热的增加则增强了该比值。
The present work investigates analytically the problem of forced convection heat transfer of a pulsating flow, in a channel filled with a porous medium under local thermal non-equilibrium condition. Internal heat generation is considered in the porous medium and the channel walls are subjected to constant heat flux boundary condition. Exact solutions are obtained for velocity, Nusselt number and temperature distributions of the fluid and solid phases in the porous medium. The influence of pertinent parameters, including Biot number, Darcy number, fluid to solid effective thermal conductivity ratio and Prandtl number are discussed. The applied pressure gradient is considered in a sinusoidal waveform. The effect of dimensionless frequency and coefficient of the pressure amplitude on the system’s velocity and temperature fields are discussed. The general shape of the unsteady velocity for different times found to be very similar to the steady data. Results show that the amplitudes of the unsteady temperatures for the fluid and solid phases decrease with the increase in Biot number or thermal conductivity ratio. For large Biot numbers, dimensionless temperatures of the solid and fluid phases are similar and are close to their steady counterparts. Results for the Nusselt number indicate that increasing Biot number or thermal conductivity ratio decreases the amplitude of Nusselt number. Increase in the internal heat generation in the solid phase does not have a significant influence on the ratio of amplitude-to-mean value of the Nusselt number, while internal heat generation in the fluid phase enhances this ratio.