The proposed study focuses on the effect of double diffusive convection on the flow structures of power-law fluids between two coaxial cylinders of finite aspect ratios with end caps. We adopted a D2Q9 axisymmetric lattice Boltzmann model to predict the power-law fluid flow and D2Q4 (Lattice Boltzman method) model for azimuthal velocity, concentration, and the temperature. For $N=0$ ($N$ is the solutal and thermal buoyancy forces ratio), fixed Taylor number $Ta$ with increasing Rayleigh number $Ra$, the thermal base flow regime is more pronounced for the pseudoplastic fluid compared to the dilatant fluid. In addition, the thermal base flow in the annulus is delayed when $n$ increases. Thus, the increase of the behavior index $n$ has a stabilizing effect on the flow structure. On the other hand, when $N>0$, the solute buoyancy forces in the annulus prevail over the centrifugal and thermal buoyancy forces, and the flow becomes ultimately a solute base flow for $N=3$. For $N<0$, the flow becomes a thermal base flow for $N=-1$. Thus, the mass transfer with negative $N$ values has a greater stabilizing effect on the flow structures than with positive $N$.

拟议的研究侧重于双扩散对流对两个带端盖的有限纵横比同轴圆柱之间幂律流体的流动结构的影响。我们采用 D2Q9 轴对称晶格 Boltzmann 模型来预测幂律流体流动，并采用 D2Q4（晶格 Boltzman 方法）模型来预测方位速度、浓度和温度。为了$N=0$ ($N$ 是溶质和热浮力比），固定泰勒数 $吨\mathrm{一种}$ 随着瑞利数的增加 $\mathrm{电阻}\mathrm{一种}$，与膨胀流体相比，假塑性流体的热基础流动状态更为明显。此外，当环空的热基流被延迟时$n$增加。因此，行为指数的增加$n$对流动结构有稳定作用。另一方面，当$N>0$，环形空间中的溶质浮力超过离心力和热浮力，并且流动最终成为溶质基流 $N=3$. 为了$N<0$，流动成为热基流 $N=-1$. 因此，负传质$N$ 值对流动结构的稳定作用比正值更大 $N$.