Nonlinear convection with variable coefficient of thermal expansion
The problem of nonlinear convection in a horizontal layer of fluid with variable coefficient of thermal expansion is considered. It is found that square cells transport always more heat than two-dimensional rolls and that rolls are always unstable. Variable coefficient of thermal expansion can strongly affect the critical Rayleigh number and the horizontal scale of the motion. Subcritical instabilities can exist which are associated with either hexagon pattern convection or square pattern convection. Particular forms of the coefficient thermal expansion are essential to determine the preferred flow patterns which could be of the forms of squares or hexagons with either upward of downward motion at the cells' centers.
variable coefficient of thermal expansion
scientific article; zbMATH DE number 3945676