{"title":"Transition and heat transfer in a water filled cubic cavity with convectively heated sidewalls","authors":"Md Harun Rashid , Feng Xu","doi":"10.1016/j.ijthermalsci.2025.109913","DOIUrl":null,"url":null,"abstract":"<div><div>Transition and heat transfer in a water filled cubic cavity with convectively heated sidewalls are investigated using three dimensional numerical simulations due to the practical significance in environment and industry. The numerical study is performed for a range of Rayleigh number (<em>Ra</em>) from 10<sup>0</sup> to 5 × 10<sup>8</sup> for which the working fluid is water (Pr = 7.74). Such a range of Rayleigh numbers shows a complex transition route to chaos of natural convection involving successive bifurcations. The first pitchfork bifurcation occurs under steady convection regime between <em>Ra</em> = 3.3 × 10<sup>4</sup> and <em>Ra</em> = 3.4 × 10<sup>4</sup> based on the topologic invariant relation. Further, more pitchfork bifurcations happen as <em>Ra</em> is increased. Additionally, a Hopf bifurcation occurs between <em>Ra</em> = 2.6 × 10<sup>9</sup> and <em>Ra</em> = 2.7 × 10<sup>9</sup> at which natural convection becomes periodic. Further bifurcations may also occur between <em>Ra</em> = 3.2 × 10<sup>9</sup> and <em>Ra</em> = 3.3 × 10<sup>9</sup> from periodic to period doubling state and between <em>Ra</em> = 3.3 × 10<sup>9</sup> and <em>Ra</em> = 3.4 × 10<sup>9</sup> from period doubling to quasi-periodic state. For a large Rayleigh number of <em>Ra</em>≥3.9 × 10<sup>9</sup>, natural convection becomes chaotic. To characterize the transition to chaos, topologic invariant relation, spectrum, attractor, maximum Lyapunov exponent, and fractal dimension are adopted. In addition, heat transfer is analyzed and scaled under different regimes.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"214 ","pages":"Article 109913"},"PeriodicalIF":4.9000,"publicationDate":"2025-04-03","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/S1290072925002364","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
Transition and heat transfer in a water filled cubic cavity with convectively heated sidewalls are investigated using three dimensional numerical simulations due to the practical significance in environment and industry. The numerical study is performed for a range of Rayleigh number (Ra) from 100 to 5 × 108 for which the working fluid is water (Pr = 7.74). Such a range of Rayleigh numbers shows a complex transition route to chaos of natural convection involving successive bifurcations. The first pitchfork bifurcation occurs under steady convection regime between Ra = 3.3 × 104 and Ra = 3.4 × 104 based on the topologic invariant relation. Further, more pitchfork bifurcations happen as Ra is increased. Additionally, a Hopf bifurcation occurs between Ra = 2.6 × 109 and Ra = 2.7 × 109 at which natural convection becomes periodic. Further bifurcations may also occur between Ra = 3.2 × 109 and Ra = 3.3 × 109 from periodic to period doubling state and between Ra = 3.3 × 109 and Ra = 3.4 × 109 from period doubling to quasi-periodic state. For a large Rayleigh number of Ra≥3.9 × 109, natural convection becomes chaotic. To characterize the transition to chaos, topologic invariant relation, spectrum, attractor, maximum Lyapunov exponent, and fractal dimension are adopted. In addition, heat transfer is analyzed and scaled under different regimes.
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.