## The Rayleigh-Benard Convection in Rarefied Gases

• In the present paper we investigate the Rayleigh-Benard convection in rarefied gases and demonstrate by numerical experiments the transition from purely thermal conduction to a natural convective flow for a large range of Knudsen numbers from 0.02 downto 0.001. We address to the problem how the critical value for the Rayleigh number defined for incompressible vsicous flows may be translated to rarefied gas flows. Moreover, the simulations obtained for a Knudsen number Kn=0.001 and Froude number Fr=1 show a further transition from regular Rayleigh-Benard cells to a pure unsteady behavious with moving vortices.

Author: Carlo Cercignani, Maria Cristina Giurin, Jens Struckmeier urn:nbn:de:hbz:386-kluedo-5987 Berichte der Arbeitsgruppe Technomathematik (AGTM Report) (192) Preprint English 1998 1998 Technische Universität Kaiserslautern Boltzmann Equation ; Numerical Simulation; Rarefied Gas Flows ; Rayleigh Number Fachbereich Mathematik 510 Mathematik

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