Abstract:
The problem related to thermosolutal natural laminar and permanent convection
in horizontal annulus situated between two eccentric cylinders filled with Newtonian and
incompressible binary fluid oriented at an arbitrary angle is examined numerically. The
inner cylinder is heated with hot temperature T1 and high concentration S1 while the outer
cylinder is maintained at a cold constant temperature T2 and low concentration S2. The fluid is air and the substance diffused in the enclosure is the vapor. The flow is driven by the thermal and solutal buoyancies. The annular space is filled by a Newtonian and
incompressible fluid. The number of Prandtl is fixed at (0.71) but the thermal Rayleigh
number, the Lewis number, the slope angle, the relative eccentricity and the buoyancy ratio
vary. By using the approximation of Boussinesq and the vorticity-stream function
formulation, the flow is modeled by the differential equations with the derivative partial: the
equations of continuity, the momentum, the energy and mass are expressed in a frame of
reference known as "bicylindrical", to facilitate the writing of the boundary conditions and to
transform the curvilinear field into a rectangular one. A computer code was developed, the
latter uses finished volumes, for the discretization of the equations and in order to show its
reliability, the authors compare results resulting from the latter with other similar results
existing in the literature and they examine the effects of the slope of the system, of the relative eccentricity, of the thermal Rayleigh number, of the Lewis number and of the buoyancy ratio values on the results obtained that it is qualitatively or quantitatively.
