The variable gravity field and viscous dissipation effects on the double diffusive and Soret driven convective instability in a porous layer with throughflow

摘要

The influence of the Soret parameter, variable gravity field and viscous dissipation on the stability of convection with double-diffusion in a porous layer saturated by a viscous fluid is considered numerically. The impact of vertical throughflow on stability is also studied. Linear, quadratic, cubic and exponential functions are taken into consideration for gravity force variation. To solve the eigenvalue problem numerically, bvp4c method has been employed. The results show that Lewis number, gravity variation parameter, and Soret parameter are delaying the onset of convection, while solutal Rayleigh number and viscous dissipation parameter are enhancing the onset of convection in the flow field. It is distinguished that the system is becoming more stable for the exponential variation of the gravity field and more unstable for cubic variation of gravity variation.