小长高比腔体内的摆动行波

Undulation travelling wave in a small aspect rectangur cell

通过流体力学基本方程组的数值模拟,探讨了具有Soret效应(分离比ψ=?0.47)和小长高比(Γ=8)腔体中混合流体摆动行波对流的动力学特性。研究表明:在相对瑞利数r<3.467时系统出现了行波状态;在r=3.647～6.227的范围内,发现了摆动行波对流;且对流振幅随着时间的变化存在两种不同特性,其摆动周期随瑞利数r增大而减小,对流振幅和努塞尔数随瑞利数r增大而增加;当r增大到r=6.228时,摆动行波过渡到定常对流状态。因此,在行波对流向定常对流过渡的过程中存在摆动行波对流.

By using a two-dimensional numerical simulation of the fully hydrodynamic equations, the dynamics of the undulation traveling wave(UTW) convection in binary fluid mixtures with strong Soret effect (the separation ratio ψ = ?0 .47)and with a small aspect rectangular cell Γ = 8is studied. The traveling wave convection at the reduced Rayleigh number r < 3.467and the UTW convection over the range of r =3.647～6.227 are found. The variation of convection amplitude for the UTW with time has two different models. The oscilatory period of the UTW convection decreases with increasing of r, the convection amplitude and Nusselt number increase with r . The UTW convection transits to a stationary overturning convection (SOC) state when r is increased to r = 6.228. Therefore, the UTW convection exists in the transition from traveling wave convection to SOC.