Unravelling Thermal Efficiency of Hybrid Casson Nanoliquid Flow Through Sensitivity Analysis

The current research aims to endeavour the dynamics of Casson hybrid nanoliquid flow past a horizontal moving plate incorporating an irregular heat source and the thermal convective constraint at the wall. The nonlinear PDEs governing the flow are formulated using the Tiwari-Das model and further resolved in MATLAB with the aid of the built-in finite difference algorithm-based bvp5c scheme and apposite transformations. Moreover, the behaviour of the Cu-Al₂O₃ hybrid Casson nanoliquid (HCNL) has been compared to that of the Cu-Casson nanoliquid and Casson fluid. Per unit change in the volume fraction of alumina nanoparticles ascends the drag coefficient by 77.50% when \(\lambda =0.5\) $\lambda =0.5$ and descends the friction factor by 107.92% when \(\lambda =1.5\) $\lambda =1.5$ . The response surface methodology (RSM) has been employed to assess the consequence of the space-dependent heat source (SHS) parameter \(\left(0.02\le {\alpha }_{1}\le 0.04\right)\) $\left(0.02,\le ,{\alpha }_1,\le ,0.04\right)$ , volume fraction of copper nanoparticles \(\left(0.01\le {\phi }_{1}\le 0.09\right)\) $\left(0.01,\le ,{\varphi }_1,\le ,0.09\right)$ , and volume fraction of alumina nanoparticles \(\left(0.01\le {\phi }_{2}\le 0.09\right)\) $\left(0.01,\le ,{\varphi }_2,\le ,0.09\right)$ on the heat transfer properties. It can be noted that the addition of copper nanoparticles tends to decline the Nusselt number. Further, sensitivity analysis is also carried out to determine which input parameters profoundly influence the model outputs. It is observed that the SHS parameter showcases negative sensitivity with the Nusselt number.