Analytical solution for transient laminar fully developed free convection in open-ended vertical concentric porous annuli

摘要: Free and mixed convection problems in a vertical porous annulus have been extensively studied. These studies use numerical or experimental techniques to investigate the thermal behavior of mental annulus. Parang Keyhani obtained closed-form solutions for special case where inner outer walls are heated by uniform but unequal heat fluxes. The lack analytical transient fully developed laminar natural concentric annuli, with different fundamental combinations isothermal isoflux boundary conditions, motivated present work. purpose this paper is present, closed forms, free solutions, corresponding four conditions annuli. obtained, which take both Darcian Brinkman effects into consideration, may be used as preliminary check more practical situations. 4 refs.