NUMERICAL STUDY OF THERMAL COUPLING BETWEEN CONDUCTIVE WALLS AND A BOUSSINESQ STRATIFIED FLUID

Abstract

A numerical procedure is developed to predict the time-dependent natural convection induced in an initially quiescent and stratified Boussinesq fluid by the presence of thermally conducting sidewalls. The time evolution of the fluid velocity and temperature fields is obtained by solving the two-dimensional unsteady Navier-Stokes equations with an algorithm that combines a pseudo-spectral Chebyshev space discretization with a finite-difference time-stepping scheme. The coupling between the walls and fluid temperatures is ensured iteratively at each time step, The procedure is applied to the study of the thermocline degradation in thermal storage tanks. The influence of the convection on the decay of the initial stratification is discussed for various wall to fluid heat conductivity and thermal diffusivity ratios, fluid aspect ratios, and initial Rayleigh numbers.

Additional information

Notes on contributors

P. Joubert

present address is I.U.T. Génie Civil, 17026 La Rochelle cedex, France.

P. Le Quéré

present address is LIMSI-CNRS, BP 30, 91406, Orsay cedex, France.