Numerical simulations on natural convection in a square cavity containing a circular pipe

Numerical method was employed to investigate the two-dimensional laminar natural convection in a square cavity containing a circular pipe. Rayleigh number one based on the temperature difference between the cold and hot wall is 106, and Rayleigh number two based on the quantity of heat transfer through the pipe varied from 0 to 108. The results indicate that the flow field in the cavity presents complex variation with enhanced buoyancy as Rayleigh number two increases. Also, fluid in cavity first obtains heat from hot wall and then transfer heat to it when Rayleigh number two increases. With a larger Rayleigh number two, part of the fluid next to the hot wall obtains heat from it while the other transfer heat to it at the same time.The results presented in this paper can be a reference for engineering design.