缺陷源S型周期移动的对传波

Dynamic characteristics of the counterpropagating waves with S type periodic motion of defect source

该文利用SIMPLE算法求解混合流体对流的流体力学方程组,研究了分离比ψ(28)-0.2及长高比Γ(28)12,20和40情况下缺陷源S型周期移动的对传波的动力学特性。结果发现,缺陷源S型周期移动的对传波存在的下限以下是有缺陷的行波,对传波存在的上限以上可以是不同的行波。缺陷源随着时间在腔体内作"s"型变化。随着相对瑞利数r的增加,缺陷源S型周期移动的对传波摆动周期变长,摆动振幅变小。对传波的存在区间,对传波存在区间的上限值,对传波摆动周期随着长高比Γ的增加而变大。Γ(28)12时,对传波的分支上没有出现缺陷结构;Γ(28)02时,对传波的半个周期内只有一个分支出现具有缺陷的行波;Γ(28)40时,对传波的半个周期内多个分支出现具有多个缺陷的行波。因此,随着Γ的增大,对传波分支上的缺陷增加,对流结构变得比较复杂。

In this paper, the SIMPLE algorithm is used to solve the equations of fluid mechanics in a binary fluid convection, and the dynamic characteristics of the counterpropagating waves with S type periodic motion of defect source at separation ratio ψ（28）-0.2 and at aspect ratio Γ（28）12, 20 and 40 are studied. It is found that system appears traveling wave with defect below the lower limit of the counterpropagating waves with S type periodic motion of defect source, and appears different type traveling waves above the lower limit of the counterpropagating waves. The defect source is of ＂s＂ type variation with time in the cavity. With the increase of reduced Rayleigh number, the period of oscillation of the counterpropagating waves with S type periodic motion of defect source is longer and the amplitude of oscillation is smaller. With the increase of aspect ratio Γ, the range of existence,the upper limit of the range of existence and the period of oscillation of the counterpropagating waves become larger. The defect structure does not appear on the branch of the counterpropagating waves at Γ（28）12. The defect structures appear on one branch of the counterpropagating waves during half period of oscillation at Γ（28）20.The defect structures appear on several branchs of the counterpropagating waves during half period of oscillation at Γ（28）40.Therefore, the defects on the branchs of the counterpropagating waves increase and the convective structure becomes more complex with increasing Γ.