{"title":"随蒸发而下降的自由面湍流自然对流的数值研究","authors":"Lise Ceresiat, Miltiadis V. Papalexandris","doi":"10.1007/s10494-025-00664-5","DOIUrl":null,"url":null,"abstract":"<div><p>In this paper we report on Large Eddy Simulations of natural convection in water pools with evaporation across the free surface and at the hard turbulence regime. The free surface is approximated as a free-slip top boundary. The loss of water is estimated via a dynamic and inhomogeneous evaporation model. Also, the descent of the free surface is accounted for by regularly reducing the computational domain and applying a remeshing procedure. We present results for 4 different Rayleigh numbers, ranging from <span>\\(\\boldsymbol{Ra = 1.35 \\times {10^8}}\\)</span> to <span>\\(\\boldsymbol{Ra{ = 10^{10}}}\\)</span>. Our simulations predict a slow decrease of the free-surface temperature and evaporation rate over time. This may be attributed to the descent of the free surface due to evaporation which tends to reduce the intensity of turbulent motions. On the other hand, the flow structure remains the same throughout the duration of the simulations. More specifically, the flow is organized in a large scale circulation aligned in a diagonal plane with smaller convective rolls near the corners of the domain. Also, the absence of a top hydrodynamic boundary layer enhances turbulent mixing and convective heat transfer near the free surface. This enhancement is manifested by a shift of the profile of the mean surface temperature towards the upper part of the domain, with the shift becoming more pronounced as the turbulence intensity increases. Herein we also provide results for the Nusselt number <span>\\(\\boldsymbol{Nu}\\)</span> and present a new <span>\\(\\boldsymbol{Nu - Ra}\\)</span> scaling for convection in pools and cavities that covers a large range of turbulence intensities.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"115 2","pages":"469 - 494"},"PeriodicalIF":2.4000,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Numerical Study of Turbulent Natural Convection with a Descending Free Surface Due to Evaporation\",\"authors\":\"Lise Ceresiat, Miltiadis V. Papalexandris\",\"doi\":\"10.1007/s10494-025-00664-5\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In this paper we report on Large Eddy Simulations of natural convection in water pools with evaporation across the free surface and at the hard turbulence regime. The free surface is approximated as a free-slip top boundary. The loss of water is estimated via a dynamic and inhomogeneous evaporation model. Also, the descent of the free surface is accounted for by regularly reducing the computational domain and applying a remeshing procedure. We present results for 4 different Rayleigh numbers, ranging from <span>\\\\(\\\\boldsymbol{Ra = 1.35 \\\\times {10^8}}\\\\)</span> to <span>\\\\(\\\\boldsymbol{Ra{ = 10^{10}}}\\\\)</span>. Our simulations predict a slow decrease of the free-surface temperature and evaporation rate over time. This may be attributed to the descent of the free surface due to evaporation which tends to reduce the intensity of turbulent motions. On the other hand, the flow structure remains the same throughout the duration of the simulations. More specifically, the flow is organized in a large scale circulation aligned in a diagonal plane with smaller convective rolls near the corners of the domain. Also, the absence of a top hydrodynamic boundary layer enhances turbulent mixing and convective heat transfer near the free surface. This enhancement is manifested by a shift of the profile of the mean surface temperature towards the upper part of the domain, with the shift becoming more pronounced as the turbulence intensity increases. Herein we also provide results for the Nusselt number <span>\\\\(\\\\boldsymbol{Nu}\\\\)</span> and present a new <span>\\\\(\\\\boldsymbol{Nu - Ra}\\\\)</span> scaling for convection in pools and cavities that covers a large range of turbulence intensities.</p></div>\",\"PeriodicalId\":559,\"journal\":{\"name\":\"Flow, Turbulence and Combustion\",\"volume\":\"115 2\",\"pages\":\"469 - 494\"},\"PeriodicalIF\":2.4000,\"publicationDate\":\"2025-06-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Flow, Turbulence and Combustion\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s10494-025-00664-5\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MECHANICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Flow, Turbulence and Combustion","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s10494-025-00664-5","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MECHANICS","Score":null,"Total":0}
Numerical Study of Turbulent Natural Convection with a Descending Free Surface Due to Evaporation
In this paper we report on Large Eddy Simulations of natural convection in water pools with evaporation across the free surface and at the hard turbulence regime. The free surface is approximated as a free-slip top boundary. The loss of water is estimated via a dynamic and inhomogeneous evaporation model. Also, the descent of the free surface is accounted for by regularly reducing the computational domain and applying a remeshing procedure. We present results for 4 different Rayleigh numbers, ranging from \(\boldsymbol{Ra = 1.35 \times {10^8}}\) to \(\boldsymbol{Ra{ = 10^{10}}}\). Our simulations predict a slow decrease of the free-surface temperature and evaporation rate over time. This may be attributed to the descent of the free surface due to evaporation which tends to reduce the intensity of turbulent motions. On the other hand, the flow structure remains the same throughout the duration of the simulations. More specifically, the flow is organized in a large scale circulation aligned in a diagonal plane with smaller convective rolls near the corners of the domain. Also, the absence of a top hydrodynamic boundary layer enhances turbulent mixing and convective heat transfer near the free surface. This enhancement is manifested by a shift of the profile of the mean surface temperature towards the upper part of the domain, with the shift becoming more pronounced as the turbulence intensity increases. Herein we also provide results for the Nusselt number \(\boldsymbol{Nu}\) and present a new \(\boldsymbol{Nu - Ra}\) scaling for convection in pools and cavities that covers a large range of turbulence intensities.
期刊介绍:
Flow, Turbulence and Combustion provides a global forum for the publication of original and innovative research results that contribute to the solution of fundamental and applied problems encountered in single-phase, multi-phase and reacting flows, in both idealized and real systems. The scope of coverage encompasses topics in fluid dynamics, scalar transport, multi-physics interactions and flow control. From time to time the journal publishes Special or Theme Issues featuring invited articles.
Contributions may report research that falls within the broad spectrum of analytical, computational and experimental methods. This includes research conducted in academia, industry and a variety of environmental and geophysical sectors. Turbulence, transition and associated phenomena are expected to play a significant role in the majority of studies reported, although non-turbulent flows, typical of those in micro-devices, would be regarded as falling within the scope covered. The emphasis is on originality, timeliness, quality and thematic fit, as exemplified by the title of the journal and the qualifications described above. Relevance to real-world problems and industrial applications are regarded as strengths.