Mondal Pranab Kumar, Wongwises Somchai
Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India.
Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab (FUTURE), Department of Mechanical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
Entropy (Basel). 2018 Jan 11;20(1):50. doi: 10.3390/e20010050.
We investigate the effect of viscous dissipation on the thermal transport characteristics of heat and its consequence in terms of the entropy-generation rate in a circular Couette flow. We consider the flow of a Newtonian fluid through a narrow annular space between two asymmetrically-heated concentric micro-cylinders where the inner cylinder is rotating at a constant speed. Employing an analytical methodology, we demonstrate the temperature distribution and its consequential effects on the heat-transfer and entropy-generation behaviour in the annulus. We bring out the momentous effect of viscous dissipation on the underlying transport of heat as modulated by the degree of thermal asymmetries. Our results also show that the variation of the Nusselt number exhibits an unbounded swing for some values of the Brinkman number and degrees of asymmetrical wall heating. We explain the appearance of unbounded swing on the variation of the Nusselt number from the energy balance in the flow field as well as from the second law of thermodynamics. We believe that the insights obtained from the present analysis may improve the design of micro-rotating devices/systems.
我们研究了粘性耗散对热传输特性的影响及其在圆形库埃特流中熵产生率方面的后果。我们考虑牛顿流体在两个非对称加热的同心微圆柱之间的狭窄环形空间中的流动，其中内圆柱以恒定速度旋转。采用一种分析方法，我们展示了温度分布及其对环形空间中传热和熵产生行为的相应影响。我们揭示了粘性耗散对由热不对称程度调制的热传输的重要影响。我们的结果还表明，对于某些布林克曼数和不对称壁加热程度的值，努塞尔数的变化呈现出无界波动。我们从流场中的能量平衡以及热力学第二定律解释了努塞尔数变化中无界波动的出现。我们相信，从本分析中获得的见解可能会改进微旋转装置/系统的设计。
