Natural Convection Heat and Mass Transfer in the Boundary Layer along a Vertical Cylinder with Opposing Buoyancies

• Published in: Journal of applied fluid mechanics 2011, Vol.4 (4), p.15-21
• Main Authors: Abdallah, M Si, Zeghmati, B
• Format: Article
• Language: English
• Subjects: Algorithms; Boundary conditions; Boundary layer; Boundary layer equations; Boundary layers; Buoyancy; Buoyancy force; Computational fluid dynamics; Convection; Cylinders; Finite difference method; Flat plates; Fluid flow; Free convection; Heat transfer; Magnetism; Mass transfer; Mathematical models; Newtonian fluids; Prandtl number; Scandium; Schmidt number; Temperature; Vertical cylinder; Vertical cylinders
• ISSN: 1735-3572; 1735-3645; 1735-3645
• DOI: 10.36884/jafm.4.04.11941

The effects of opposing buoyancies on natural convection heat and mass transfer in the boundary layer over a vertical cylinder immersed in a quiescent Newtonian fluid are presented in this paper. The surface of the cylinder is maintained at a constant temperature and concentration. The homotopic transformation is proposed to transform the physical domain into a flat plate. The boundary layer equations and the boundary conditions are solved numerically using an implicit finite difference scheme and the Gauss-Seidel algorithm. The buoyancy ratio N, Prandtl number Pr and Schmidt number Sc are important parameters for this problem. The numerical results for Pr=Sc and Pr not equal to Sc, including the velocity, temperature, concentration fields and the Nusselt number as well as the Sherwood number along the surface of the cylinder are discussed for aiding and opposing buoyancies. Results show that the Nusselt (Sherwood) number increases with positive or negative buoyancies ration N (N=Grc/Grt). Moreover, for opposing flows with Sc