Co-existence of Multiple Steady States in Bottom Heated Trapezoidal Closed Cavities

The natural convection in bottom heated symmetric trapezoidal closed cavities filled with air is studied, where inclined side walls were adiabatic. From the simulations, it is observed that multiple stable steady states coexist in obtuse angle trapezoidal cavities (OATZC) beyond critical Rayleigh number (Ra). Out of these, two solutions are mirror image solutions due to the symmetry of OATZC about vertical midplane. Multiple stable steady states in square cavities, having numbers even, have been documented in the literature; however, in the case of the OATZC, odd numbers of coexisting solutions are found, and no such study has been reported previously. The isotherms, velocity profiles, and Nusselt number behaviour have been shown as proof of the same.