Convective Heat Transfer in Brinkman–Darcy–Kelvin–Voigt Fluid with Variable Gravity and Generalized Maxwell–Cattaneo Law
摘要
This article investigates thermal convection in Kelvin–Voigt fluids saturating a Brinkman–Darcy-type porous medium under variable gravity effects. The stability analysis encompasses linear, nonlinear conditional, and nonlinear unconditional regimes, leveraging the generalized Maxwell–Cattaneo law for heat flux. Normal mode technique is applied for linear analysis, while nonlinear governing equations for conditional and unconditional stability are derived using energy methods. The compound matrix method is utilized to compute critical Rayleigh numbers and corresponding wave numbers. Numerical computations are performed in MATLAB to determine all critical values, with graphical results illustrating stability trends. Six gravity variation profiles are examined, revealing that the gravity modulation parameter