Thermal instability of Tri-hybrid Casson nanofluid with thermal radiation saturated porous medium in different enclosures

In this paper, authors have studied the thermal instability of Tri-hybrid Casson nanofluid with thermal radiation saturated porous medium within four different types of enclosures using both linear and nonlinear ways. Linear stability analysis is done using the normal mode approach, whereas nonlinear stability analysis is done using the truncated Fourier series method. The results demonstrate that the porosity, thermal radiation, and porous parameter stabilize the system. On the other hand, the Casson parameter advances the initiation of convective motion in the system. To understand the behaviour of mass/heat transfer in the system two different approaches viz Mathematica NDSolve and Runge-Kutta-Fehlberg method (RKF-45) are used, and it is found that the rate of heat/mass transfer is exactly the same in both cases. The study examines three distinct enclosures and compares their effects on the onset of convection and heat/mass transport. In comparison of different enclosures the tall enclosures have a quicker onset of convection other than square and shallow enclosures. The tall enclosure accelerates mass/heat transfer more quickly than the square and shallow enclosure. The results are illustrated graphically and in tabular form.