International Journal of Numerical Methods for Heat & Fluid Flow ( IF 4.2 ) Pub Date : 2021-02-24 , DOI: 10.1108/hff-10-2020-0614 Stepan Mikhailenko , Mohammad Ghalambaz , Mikhail A. Sheremet
Purpose
This paper aims to study numerically the simulation of convective–radiative heat transfer under an effect of variable thermally generating source in a rotating square chamber. The performed analysis deals with a development of passive cooling system for the electronic devices.
Design/methodology/approach
The domain of interest of size H rotating at a fixed angular velocity has heat-conducting solid walls with a constant cooling temperature for the outer boundaries of the vertical walls and with thermal insulation for the outer borders of the horizontal walls. The chamber has a heater on the bottom wall with a time-dependent volumetric heat generation. The internal surfaces of the walls and the energy element are both grey diffusive emitters and reflectors. The fluid is transparent to radiation. Computational model has been written using non-dimensional parameters and worked out by the finite difference technique. The effect of the angular velocity, volumetric heat generation frequency and surface emissivity has been studied and described in detail.
Findings
The results show that growth of the surface emissivity leads to a diminution of the mean heater temperature, while a weak rotation can improve the energy transport for low volumetric thermal generation frequency.
Originality/value
An efficient computational approach has been used to work out this problem. The originality of this work is to analyze complex (conductive–convective–radiative) energy transport in a rotating system with a local element of time-dependent volumetric heat generation. To the best of the authors’ knowledge, an interaction of major heat transfer mechanisms in a rotating system with a heat-generating element is scrutinized for the first time. The results would benefit scientists and engineers to become familiar with the analysis of complex heat transfer in rotating enclosures with internal heat-generating units, and the way to predict the heat transfer rate in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors and electronics.
中文翻译:
具有随时间变化的发热固体元件和导热固体壁的旋转柜中的热对流和辐射
目的
本文旨在数值研究在旋转方腔内可变热源作用下对流-辐射传热的模拟。执行的分析涉及电子设备被动冷却系统的开发。
设计/方法/方法
以固定角速度旋转的大小为H的感兴趣域具有导热固体壁,垂直壁的外边界具有恒定的冷却温度,水平壁的外边界具有隔热。腔室的底壁上有一个加热器,可产生随时间变化的体积热。墙壁的内表面和能量元件都是灰色的漫射发射器和反射器。该流体对辐射是透明的。计算模型已使用无量纲参数编写并通过有限差分技术得出。已经详细研究和描述了角速度、体积发热频率和表面发射率的影响。
发现
结果表明,表面发射率的增长导致平均加热器温度的降低,而弱旋转可以改善低体积热产生频率的能量传输。
原创性/价值
已使用有效的计算方法来解决此问题。这项工作的独创性是分析旋转系统中复杂的(传导-对流-辐射)能量传输,该系统具有与时间相关的体积热产生的局部元素。据作者所知,旋转系统中的主要传热机制与发热元件的相互作用是第一次仔细研究。结果将使科学家和工程师熟悉带有内部发热单元的旋转外壳中复杂传热的分析,以及预测先进技术系统、工业部门(包括交通、发电、化工行业和电子行业。