Effects of internal heating and chemical reactions on triple-diffusive convection under rotation modulation

The stability of thermally driven buoyant convection in a fluid-saturated, rotating horizontally porous layer with permeable boundaries is investigated by considering a triple-diffusive convection system subjected to rotation modulation and influenced by internal heating and chemical reactions. The momentum equation is derived using Darcy's law for porous layers. A linear stability analysis is conducted using the standard normal mode technique. The critical thermal Rayleigh number at the onset of stationary convection is determined based on the physical governing parameters. The results reveal significant insight: internal heating is found to destabilize the system, while chemical reactions involving solute concentrations contribute to system stabilization, leading to both instability and stability under certain conditions. A weakly nonlinear analysis is performed using a regular asymptotic perturbation method, where perturbations are expressed as power series. Furthermore, the Ginzburg–Landau equation is derived at the stationary mode. The equation is used to investigate the influence of rotation modulation on heat and mass transport, providing valuable insight into these processes within the studied system. The effect of Coriolis force is to increase the heat and mass transmission in the system. The convective heat and mass transports in the system increase by approximately 6.1%, 7.3%, and 1.55%, respectively, with a 16% rise in the internal heating parameter.