Steady free convection in a porous medium heated from below

摘要: This is an experimental and numerical study of steady free convection in a porous medium, system dominated by single non-linear process, the advection heat. The paper presents results on three topics: (1) uniformly heated from below, for which flow cellular, as analogous Benard-Rayleigh flows, (ii) role end-effects, (iii) mass discharge. Measurements heat transfer are used to establish further validity scheme proposed author (1966a), while other flows allow more extensive under various boundary conditions. very satisfactory even though only moderately problems can be treated at present.The main new follows. For Rayleigh-type flow, above critical Rayleigh number about 40, transferred across layer proportional square temperature difference independent thermal conductivity medium or depth layer. result modified when boundary-layer thickness comparable grain size medium. investigation end-effects reveals variations horizontal wave-number pronounced hysteresis suggests alternative explanation some observations Malkus (1954).