Zhang Xiaohui,Yang Mo,Yu Min,Lu Mei£¬Xu Zhiping,Zhang Lixin
(College of Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)
Abstract:The nonlinear characteristics were inverstigated by numerical simulations for the oscillatory natural convection in an enclosure with a vertical isothermal plate.An unsteady mathematical model for the problem was solved using SIMPLE algorithm with a QUICK scheme. It is shown that the bifurcation of the numerical solutions for this flow and heat transfer occurrs in a range of Rayleigh number Ra considered, and the flow and heat transfer change from a steady state to an unsteady with the increase of Ra. Further,the numerical solution obtained is unique and steady using two different initial conditions at Ra=104, while two different numerical results can be obtained using the two different initial conditions at Ra=5¡Á104, one of which is a steady solution and the other is an oscillatory solution.
Keywords:natural convection;bifurcation;numerical simulation