Numerical investigation of spatial-developing turbulent heat transfer in forced convections at different supercritical pressures | |
Liu, Jiaming2; Zhao, Pinghui3; Lei, Mingzhun3; Yang, Suo4; Nemati, Hassan1 | |
刊名 | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER |
2020-10-01 | |
卷号 | 159 |
关键词 | Turbulent heat transfer Supercritical pressure Spatial-developing flow Direct numerical simulation |
ISSN号 | 0017-9310 |
DOI | 10.1016/j.ijheatmasstransfer.2020.120128 |
通讯作者 | Zhao, Pinghui(phzhao@mail.ustc.edu.cn) |
英文摘要 | Direct numerical simulations have been adopted to study the turbulent heat transfer in forced convections of supercritical water at two different supercritical pressures P=23 MPa and P=25 MPa in a heated pipe with constant wall heat flux and a bulk Reynolds number of Re-0 = 5400. The present study aims to reveal the mechanisms of turbulent heat transfer of superciritical fluids at different pressures in a spatial-developing flow. The results show that at the smaller pressure ratio P-r = P/P-c, where P-c is the critical pressure, the property variations become more drastic, and both the skin friction coefficient and Nusselt number become smaller. The decompositions of skin friction and Nusselt number show that it is mainly due to the large turbulence reduction along the streamwise direction. The analyses of turbulent kinetic energy (TKE), the turbulent shear stress, and the production of TKE confirm this point. Moreover, it was found that the thermophysical property fluctuations are very large and significantly influence the turbulent statistics in the supercritical fluid flows. Due to the large property fluctuations, it was found that the density-fluctuation-related terms are significant and their values are actually comparable to the mean-density-related terms. Due to their negative contributions to turbulent shear stress and turbulent heat flux, the turbulence and heat transfer are severely attenuated by the large thermophysical property fluctuations. For near-wall scaling in spatial-developing flows at supercritical pressures, the semi-local velocity transformation with a semi-local coordinate shows a better agreement in the logarithmic region. However, a clear deviation still exists, especially for mean temperature because all the transformations only incorporate the local mean property variations and cannot consider their fluctuations. (C) 2020 Elsevier Ltd. All rights reserved. |
资助项目 | Collaborative Innovation Program of Hefei Science Center, CAS[2019HSC-CIP006] ; National Key Research and Development Program of China[2017YFE030 0500] ; National Key Research and Development Program of China[2017YFE0300503] |
WOS关键词 | BOUNDARY-LAYERS ; MIXED CONVECTION ; VERTICAL TUBE ; PIPE-FLOW ; WATER ; SIMULATION ; DOWNWARD ; CHANNELS ; FLUIDS ; CO2 |
WOS研究方向 | Thermodynamics ; Engineering ; Mechanics |
语种 | 英语 |
出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
WOS记录号 | WOS:000560367300067 |
资助机构 | Collaborative Innovation Program of Hefei Science Center, CAS ; National Key Research and Development Program of China |
内容类型 | 期刊论文 |
源URL | [http://ir.hfcas.ac.cn:8080/handle/334002/92791] |
专题 | 合肥物质科学研究院_中科院等离子体物理研究所 |
通讯作者 | Zhao, Pinghui |
作者单位 | 1.Delft Univ Technol, Dept Proc & Energy, NL-2628 CB Delft, Netherlands 2.Univ Sci & Technol China, Sch Nucl Sci & Technol, Hefei 230026, Anhui, Peoples R China 3.Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Anhui, Peoples R China 4.Univ Minnesota Twin Cities, Dept Mech Engn, Minneapolis, MN 55455 USA |
推荐引用方式 GB/T 7714 | Liu, Jiaming,Zhao, Pinghui,Lei, Mingzhun,et al. Numerical investigation of spatial-developing turbulent heat transfer in forced convections at different supercritical pressures[J]. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,2020,159. |
APA | Liu, Jiaming,Zhao, Pinghui,Lei, Mingzhun,Yang, Suo,&Nemati, Hassan.(2020).Numerical investigation of spatial-developing turbulent heat transfer in forced convections at different supercritical pressures.INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,159. |
MLA | Liu, Jiaming,et al."Numerical investigation of spatial-developing turbulent heat transfer in forced convections at different supercritical pressures".INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 159(2020). |
个性服务 |
查看访问统计 |
相关权益政策 |
暂无数据 |
收藏/分享 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论