CENTER FOR APPLIED MATHEMATICS AND THEORETICAL PHYSICS
UNIVERZA V MARIBORU UNIVERSITY OF MARIBOR
KREKOVA 2 SI-2000 MARIBOR SLOVENIA
Phone +(386) (2) 2355 350 and 2355 351 $\bullet$ Fax +(386) (2) 2355 360
Robnik@uni-mb.si $\bullet$ www.camtp.uni-mb.si
PROF.DR. MARKO ROBNIK, DIRECTOR

Seminarsko predavanje
Centra za uporabno matematiko in teoreticno fiziko

Non-linear phenomena in a supercritical fluid: Onset and transient to steady-state convection

Professor Dr. Horst Meyer

Duke University, Durham NC, USA

Abstract: This talk starts with a tutorial on supercritical fluids and on convection in a Rayleigh-Benard cell. The fluid is 3He, which near the liquid-vapor critical point at $T_c =3.18 K$ behaves like other pure fluids. The combination of Rayleigh - and Schwarzschild criteria to determine the stability limit near $T_c$ is described, and the predictions are compared with experiments. After a heat flow has been started across the fluid layer, an oscillatory behavior of the temperature difference across the layer is observed versus time in the convective regime. This phenomenon is the signature of the "piston effect", which will be described. Scaled plots of both steady state - and transient characteristic times as a function of the Rayleigh number at various compressibilities and heat currents are presented. Simulations and calculations by groups in Japan and France are compared with the experimental data.
References: A. Furukawa, H. Meyer et al: Phys. Rev. E 68, 056309 (2003), H. Meyer and A.B. Kogan : Physical Review E 66, 056310 (2002), A. B. Kogan and H. Meyer: Phys. Rev. E 63, 056310 (2001)

Seminarsko predavanje bo v cetrtek 9. septembra 2004 ob 15:15 uri v seminarski sobi CAMTP, Krekova 2, pritlicje desno. Vljudno vabljeni vsi zainteresirani, tudi študentje.

Prof.Dr. Marko Robnik
-- Direktor CAMTP --