ON THERMALLY CONVECTIVE FLOW OF NANOFLUID PAST A VERTICAL FLAT SURFACE THROUGH POROUS MEDIUM FILLED WITH WATER AT 4°C: ANALYSIS OF TEMPORAL STABILITY TEST

This study scrutinizes the mixed convection nanofluid flow past a vertical flat wall in a porous medium. The convective boundary constraints with thermal radiation impacts are also considered. Copper (Cu), titanium dioxide (TiO<sub>2</sub>), and silver (Ag) are the nanomaterials, and water at 4°C is the base fluid. Similarity transformations are employed to change the governing partial differential equations (PDEs) into ordinary differential equations (ODEs). In a certain range of mixed convection parameter, dual solutions are established. Furthermore, a stability test is developed, and the smallest eigenvalues are computed using a bvp4c solver in MATLAB software. The influences of physical parameters on fluid temperature and rate of heat transport are examined and discussed. The enhancement in thermal radiation raises the temperature of the fluid. The fluid temperature also grows by elevating Biot number values. TiO<sub>2</sub> nanoparticles enhance the rate of heat transport and hence, increase the fluid temperature. The stability test confirms that only the first solution is stable.