The stability of natural convection in a fluid between two parallel vertical plates is investigated theoretically. Temperatures of the two plates are different by 2T0 and a uniform temperature gradient β (<0) is present in the vertical direction. It is found that the critical value of the Grashof number G based on T0 varies as (Formula Omitted) and an absolute instability when Ra>π4/16, where Ra is the Rayleigh number based on -β. Two numerical coefficients in the expression of Gc vary slightly with the Prandtl number smaller than 10. An abrupt decrease in Gc is attributed to a change of modes of the instability.
ASJC Scopus subject areas
- Physics and Astronomy(all)