Multiple solutions of mixed convection in a porous medium on semi-infinite interval using pseudo-spectral collocation method

One knows that calculation of all branches of solutions of nonlinear boundary value problems can be difficult even by numerical methods, especially when the boundary conditions occur at infinity. Regarding this matter, this paper considers a model of mixed convection in a porous medium with boundary conditions on semi-infinite interval which admits multiple (dual) solutions. Furthermore, pseudo-spectral collocation method is applied in erudite way to calculate both dual solutions analytically. Comparison to exact solutions reveals reliability and high accuracy of the procedure and convince to be used to obtain multiple solutions of these kind of nonlinear problems.