Amplitude equation for stationary convection in a binary viscoelastic fluid

Thermal convection in binary fluids with Oldroyd viscoelastic properties is studied close to threshold. The role of retardation time, characteristic of viscoelastic fluids, and Soret effect, characteristic of binary fluids, is emphasized. A weakly nonlinear analysis is performed for stationary convection. The coefficients of the corresponding amplitude equation are determined analytically and the nature of the bifurcation is discussed.