Finite amplitude thermal convection in non-Newtonian fluids - Fixed boundaries

In this paper the one-mode approximation, based on a variational principle of Glansdorff and Prigogine, has been used to integrate numerically the system of nonlinear differential equations describing steady convection, with hexagonal planform, in a non-Newtonian fluid with rigid boundaries. A description is given of the three methods used to integrate the equations and it is shown that the theoretical results confirm the observed increase in the Nusselt number due to visco-elastic effects and are in good agreement with the experimental results.