Effects of periodic gravity modulation in microgravity convection systems

Abstract

Natural convection in an enclosure that is subjected to periodic excitations is investigated using a classical mixed Galerkin finite element method. The modulation is incorporated in the momentum equations, through a periodic gravity function, at microgravity levels. Numerical results show the fluid motion goes through transitions from stable, to periodic, to complex, non-periodic behavior as the frequency parameter of the modulation is varied. Associated with the changing fluid motions, the average heat transfer rates increase by as much as fifty percent above the conduction limit, as the modulation frequency is decreased to low levels.