Transition between free, mixed and forced convection

Final LIMTECH Colloquium and International Symposium on Liquid Metal Technologies

材料科学;金属学

Jaeger, W.^1 ; Trimborn, F.^3,5 ; Niemann, M.^4 ; Saini, V.^4,5 ; Hering, W.^2 ; Stieglitz, R.^2 ; Pritz, B.^3 ; Fröhlich, J.^4 ; Gabi, M.^3

Institute of Fusion and Reactor Technology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, Karlsruhe

76131, Germany^1

Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen

76344, Germany^2

Institute of Fluid Machinery, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, Karlsruhe

76131, Germany^3

Institute of Fluid Mechanics, Technische Universitat Dresden, Dresden

01062, Germany^4

Laboratoire de Mécanique de Lille, Ecole Central de Lille, Boulevard Paul Langevin, Villeneuve d'Ascq Cédex

59655, France^5

关键词: CFD simulations;    Engineering applications;    Experimental investigations;    Perform designs;    Rectangular channel;    Richardson number;    Safety studies;    Thermo-hydraulic;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/228/1/012011/pdf
DOI  :  10.1088/1757-899X/228/1/012011

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In this contribution, numerical methods are discussed to predict the heat transfer to liquid metal flowing in rectangular flow channels. A correct representation of the thermo-hydraulic behaviour is necessary, because these numerical methods are used to perform design and safety studies of components with rectangular channels. Hence, it must be proven that simulation results are an adequate representation of the real conditions. Up to now, the majority of simulations are related to forced convection of liquid metals flowing in circular pipes or rod bundle, because these geometries represent most of the components in process engineering (e.g. piping, heat exchanger). Open questions related to liquid metal heat transfer, among others, is the behaviour during the transition of the heat transfer regimes. Therefore, this contribution aims to provide useful information related to the transition from forced to mixed and free convection, with the focus on a rectangular flow channel. The assessment of the thermo-hydraulic behaviour under transitional heat transfer regimes is pursued by means of system code simulations, RANS CFD simulations, LES and DNS, and experimental investigations. Thereby, each of the results will compared to the others. The comparison of external experimental data, DNS data, RANS data and system code simulation results shows that the global heat transfer can be consistently represented for forced convection in rectangular flow channels by these means. Furthermore, LES data is in agreement with RANS CFD results for different Richardson numbers with respect to temperature and velocity distribution. The agreement of the simulation results among each other and the hopefully successful validation by means of experimental data will fosters the confidence in the predicting capabilities of numerical methods, which can be applied to engineering application.