Laminar Free Convection In Horizontal Annulus Filled With Glass Beads And With Annular Fins On The Inner Cylinder

Journal of Engineering Science Pub Date : 2023-07-21 DOI:10.31026/j.eng.2013.08.06

M. Saleh, Ahmed Mohsen Katea

{"title":"Laminar Free Convection In Horizontal Annulus Filled With Glass Beads And With Annular Fins On The Inner Cylinder","authors":"M. Saleh, Ahmed Mohsen Katea","doi":"10.31026/j.eng.2013.08.06","DOIUrl":null,"url":null,"abstract":"An experimental and numerical study has been carried out to investigate the heat transfer by natural convection and radiation in a two dimensional annulus enclosure filled with porous media (glass beads) between two horizontal concentric cylinders. The outer cylinders are of (100, 82 and70mm) outside diameters and the inner cylinder of 27 mm outside diameter with (or without) annular fins attached to it. Under steady state condition; the inner cylinder surface is maintained at a high temperature by applying a uniform heat flux and the outer cylinder surface at a low temperature inside a freezer. The experiments were carried out for an annulus filled with glass beads at a range of modified Rayleigh number (4.9 ≤ Ra≤ 69), radiation parameter (0<Rd<10), with fin length of (Hf=3, 7 and 11mm), with radius ratios of (Rr=(r1/r2) =0.1405,0.2045, 0.293 and 0.3649 ), number of fins (n=0, 12, 23 and 45). Finite difference method with Boussinesq's approximation is used to solve the continuity, energy and momentum equations. The numerical solution is capable of calculating the streamline, the temperature field, the velocity field, the local and average Nusselt number. A computer program in Mat lab has been built to carry out the numerical solution. The numerical study was done for a range of modified Rayleigh number (4.9 ≤ Ra ≤ 300). Results show that the average Nusselt number is nearly constant for Ra less than 100 and increased with an increase in modified Rayleigh number.Nusselt number hardly affected by glass beads size and insignificant affected by Rd for Ra less than 100. Decreasing Rr cause clearly increase in average Nusselt number and increasing fin length or fin number decrease heat transfer.","PeriodicalId":52570,"journal":{"name":"Journal of Engineering Science","volume":"40 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Engineering Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.31026/j.eng.2013.08.06","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 0

Abstract

An experimental and numerical study has been carried out to investigate the heat transfer by natural convection and radiation in a two dimensional annulus enclosure filled with porous media (glass beads) between two horizontal concentric cylinders. The outer cylinders are of (100, 82 and70mm) outside diameters and the inner cylinder of 27 mm outside diameter with (or without) annular fins attached to it. Under steady state condition; the inner cylinder surface is maintained at a high temperature by applying a uniform heat flux and the outer cylinder surface at a low temperature inside a freezer. The experiments were carried out for an annulus filled with glass beads at a range of modified Rayleigh number (4.9 ≤ Ra≤ 69), radiation parameter (0

查看原文本刊更多论文

层流自由对流在玻璃微珠填充的水平环空和内柱上的环形翅片

在两个水平同心圆柱体之间填充多孔介质(玻璃微珠)的二维环空中进行了自然对流和辐射换热的实验和数值研究。外筒外径为(100,82和70mm)，内筒外径为27mm，并附有(或不附有)环形翅片。稳态条件下;通过在冷冻室内施加均匀的热流来保持内筒表面的高温，并使外筒表面保持低温。在修正瑞利数(4.9≤Ra≤69)、辐射参数(0

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊