An experimental investigation on forced convection heat transfer of single-phase flow in a channel with different arrangements of porous media
An experimental investigation on forced convection heat transfer of single-phase flow in a channel with different arrangements of porous media
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DOI：
10.1016/j.ijthermalsci.2018.04.030
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发表时间：
2018-12-01
影响因子：
4.5
通讯作者：
Nikian, Mohammad
中科院分区：
文献类型：
--
作者：
Baragh, Shahram;Shokouhmand, Hossein;Nikian, Mohammad
如今，多孔区内的换热在许多工业和现代应用中扮演着重要的角色。因此，在换热器的设计和分析中，与多孔介质有关的问题是重要的。本文对具有不同排列方式的多孔介质圆形截面通道内的空气单相流动进行了实验研究。考虑了流体力学参数的变化、多孔介质对通道内换热的改善以及多孔介质引起的压降。实验结果表明，由于多孔介质的存在，形成了均匀的空间和较高的导热系数，使得施加在通道壁面上的热流密度传递到流体中。此外，流体的平均温度升高，这导致通道壁面和流体平均温度之间的温差减小。由于换热系数与管壁温差和流体平均温度成反比，因此换热系数增大。为了同时研究具有压降的换热，定义了换热性能比和换热强化比。研究结果表明，无论在层流还是湍流条件下，多孔介质全填充通道都具有最好的强化换热效果。在湍流中，具有环形多孔区(邻近壁面插入的多孔区)的通道具有最好的热性能，即具有较大的换热价值和较低的压降。
Nowadays, heat transfer in porous zone plays an important role in many industrial and modern applications. For this reason, issues related to porous media are important in the design and analysis of heat exchangers. In this study, a single-phase flow of air in channel having circle cross-section with different arrangements of porous media is experimentally studied. Changes in hydrodynamic parameters, improvement of heat transfer by porous media in the channel as well as pressure drop resulted from porous media are considered. Results from these experiments show that presence of porous media leads that the thermal flux applied to walls of channel be transferred into fluid due to creating a uniform space and high conductivity of porous media. Also, the mean temperature of the fluid increases and this leads to decrease temperature difference between channel wall and the mean temperature of the fluid. Because of the heat transfer coefficient has an inverse relationship with the temperature difference between the walls of the channel and the mean temperature of the fluid, the heat transfer coefficient increases. For investigation the heat transfers with pressure drop simultaneously, heat transfer performance ratio and heat transfer enhancement ratio are defined. The results of this study show that fully filled channel of porous media has the best heat transfer enhancement (in both laminar and turbulent flows). In turbulent flow, channel with annulus shape porous zones (the porous zone inserted adjacent to wall) has the best thermal performance that means has the large value of heat transfer with low pressure drop.