Natural convection in a square cavity containing a sinusoidal cylinder

In this paper the laminar free convection in a hot outer square enclosure containing a cold inner sinusoidal circular cylinder at different amplitudes and number of undulations and different angle, is investigated by means of thermal lattice Boltzmann method (TLBM). Both square enclosure and cylinder are maintained at constant temperature and air filled the enclosure. Boundary conditions for fluid flow and temperature fields at curved boundaries are second order schemes. The buoyancy effect is modeled by applying the Boussinesq approximation to the density distribution function. The computed results show that by increasing amplitude or number of undulations or changing the angle might change the heat transfer coefficient and has profound influence on the temperature and fluid field.

► We study the effects of sinusoidal surface on heat transfer coefficients.
► By increasing the amplitudes Nusselt number increases.
► By increasing number of undulations Nusselt number might increases or decreases.
► Rotation has negligible effect on total Nusselt number.
► LBM is a powerful approach for modeling complex geometries.