{"title":"Effect of nozzle configurations and jet orientations on thermal performance of jet impingement on convex surface","authors":"Jaykumar Joshi, Santosh K. Sahu","doi":"10.1016/j.ijthermalsci.2024.109171","DOIUrl":null,"url":null,"abstract":"<div><p>The present study analyze the thermal behaviour of multiple jets impinging on a convex heated surface for two different nozzle geometries (circular and elliptical) and its orientations. Tests are performed with 5 different nozzles at different values of non-dimensional nozzle to surface distance (<em>z/d</em> = 2–10) and Reynolds number (5000–28000). At smaller value of non-dimensional nozzle to plate distance, a distinct pattern of temperature variation is observed that depend on the nozzle shape and orientation, and this pattern diminishes as surface to nozzle distance increases. In the farthest region, elliptical nozzle is found to improve the uniformity (up to 60 %) in <em>Nu</em> variation compared to the circular jets even at the largest surface to nozzle distance. The overall heat transfer is found to increase up to 18 % and the uniformity is found to enhance up to 60 %) for N-2 and N-3 nozzles. An improvement in the thermal performance is observed in the elliptical nozzle in the fountain and impingement zones. The non-uniformity in the <em>Nu</em> behaviour is found to increase with the increase in Reynolds number.</p></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Thermal Sciences","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S129007292400293X","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The present study analyze the thermal behaviour of multiple jets impinging on a convex heated surface for two different nozzle geometries (circular and elliptical) and its orientations. Tests are performed with 5 different nozzles at different values of non-dimensional nozzle to surface distance (z/d = 2–10) and Reynolds number (5000–28000). At smaller value of non-dimensional nozzle to plate distance, a distinct pattern of temperature variation is observed that depend on the nozzle shape and orientation, and this pattern diminishes as surface to nozzle distance increases. In the farthest region, elliptical nozzle is found to improve the uniformity (up to 60 %) in Nu variation compared to the circular jets even at the largest surface to nozzle distance. The overall heat transfer is found to increase up to 18 % and the uniformity is found to enhance up to 60 %) for N-2 and N-3 nozzles. An improvement in the thermal performance is observed in the elliptical nozzle in the fountain and impingement zones. The non-uniformity in the Nu behaviour is found to increase with the increase in Reynolds number.
期刊介绍:
The International Journal of Thermal Sciences is a journal devoted to the publication of fundamental studies on the physics of transfer processes in general, with an emphasis on thermal aspects and also applied research on various processes, energy systems and the environment. Articles are published in English and French, and are subject to peer review.
The fundamental subjects considered within the scope of the journal are:
* Heat and relevant mass transfer at all scales (nano, micro and macro) and in all types of material (heterogeneous, composites, biological,...) and fluid flow
* Forced, natural or mixed convection in reactive or non-reactive media
* Single or multi–phase fluid flow with or without phase change
* Near–and far–field radiative heat transfer
* Combined modes of heat transfer in complex systems (for example, plasmas, biological, geological,...)
* Multiscale modelling
The applied research topics include:
* Heat exchangers, heat pipes, cooling processes
* Transport phenomena taking place in industrial processes (chemical, food and agricultural, metallurgical, space and aeronautical, automobile industries)
* Nano–and micro–technology for energy, space, biosystems and devices
* Heat transport analysis in advanced systems
* Impact of energy–related processes on environment, and emerging energy systems
The study of thermophysical properties of materials and fluids, thermal measurement techniques, inverse methods, and the developments of experimental methods are within the scope of the International Journal of Thermal Sciences which also covers the modelling, and numerical methods applied to thermal transfer.