Numerical study of natural convection heat transfer of a Non-Newtonian power-law fluid inside a triangular cavity containing an isothermal heat source

In this study, the natural convective heat transfer in a triangular enclosure filled with a non-Newtonian power-law fluid is investigated. A triangular heat source with a constant temperature of Th is embedded inside the enclosure. The enclosure is an equilateral triangle with side l and the heater is an equilateral triangle with side b. The sidewalls of the enclosure are kept at a cold temperature of Tc and the lower wall is thermally insulated. The governing differential equations are transformed into algebraic equations by the finite element method and are solved using the integrated direct method in the Camsul software. The effects of relevant parameters such as the Rayleigh number, the power-law index, and the size of the heat source are investigated on the flow and temperature fields. The results show that increasing the Rayleigh number, especially for shear thinning fluids (n<1), increases the heat transfer rate The results also show that depending on the Rayleigh number and the power-law index, the size of the heat source has a significant effect on the flow field and thermal performance of the enclosure.