Linear analysis of convective instability of a fluid in a horizontal annular cavity occupied by a porous medium

The problem of convective instability in an infinite horizontal annular porous stratum located in an impermeable rock mass is considered. Using the Bubnov-Galerkin method, the values of the first seven critical Rayleigh numbers are found. The forms of the corresponding critical motions are established. The change in the modes of instability of the critical motions when the thickness of the porous stratum is varied is analyzed.Makhachkala. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 19–25, May–June, 1996.