资源环境科技发展态势分析平台

We studied the influence of the diffusion contrast between species on the dynamics of Rayleigh-Benard (RB) convection in porous media. The onset time of buoyancy-driven instabilities and convective dissolution flux was quantified using linear stability analysis and direct numerical simulations. The parametric analysis indicates eight distinct instability regions. Different stability mechanisms were characterized over the given range of diffusivity and relative buoyancy ratios. In particular, transition from instabilities solely by double diffusion to RB convection was identified using linear stability analysis and confirmed using nonlinear simulations. The parametric analysis on the onset also indicates that double diffusion has a potential to accelerate or slow down the RB convection depending on the solutes diffusion contrast. This study provides new insight into the effect of diffusion contrast and can be used to develop strategies for acceleration and deceleration of buoyancy-driven instabilities.