Sensitivity analysis of MHD Casson hybrid nanofluid and heat transfer with Joule heating

Purpose The current study investigates the mixed convection MHD Casson hybrid nanofluid flow and heat transfer over a circular cylinder with thermal radiation and Joule heating effects. Additionally, this study investigates the significance of flow concerning physical parameters through parametric optimization, utilizing sensitivity analysis. Design/methodology/approach The momentum and thermal boundary layer problem is transformed into dimensionless partial differential equations by utilizing the similarity transformation. The transformed system is discretized using the central difference approximation combined with the quasi-linearization technique, which gives a system of algebraic equations that are subsequently solved utilizing the LU decomposition method. In sensitivity analysis, a response surface methodology is used to derive the correlations between output responses, such as the Nusselt number and skin friction coefficient and input factors like thermal radiation, magnetic parameter and heat generation/absorption parameter. Findings It is noted that the impact of magnetic and Casson fluid parameters reduces skin friction but increases the heat transfer rate at the surface. The interaction of the Joule heating parameter with electrically conductive hybrid nanofluids increased the skin friction. The statistical results show that the heat generation/absorption on skin friction and Nusselt number is more effective than other parameters. The results of this study are valuable for various engineering applications, including energy systems such as nuclear reactors, solar collectors, industrial processes involving heat exchangers, chemical reactors, metal-forming operations, etc. Originality/value The reviewed literature designates that there are still gaps and unexplored aspects in the heat transfer transport phenomena of MHD convective flow of non-Newtonian Casson hybrid nanofluid over a cylinder with thermal radiation and heat generation/absorption effects. It is important to highlight the flow dominant physical parameters through parametric optimization with sensitivity analysis. To perform sensitivity analysis, an empirical correlation is developed using response surface methodology for various physical parameters during formulation of the flow problem, such as thermal radiation (0.0 = Rd = 2.0), magnetic (0.0 = M = 3.0) and heat generation/absorption parameters (−0.2 = Q = 0.2). The Keller Box method with MATLAB software has been employed to investigate the solution of the governing PDEs, and sensitivity analysis has been performed using response surface methodology. The response surface technique has been applied to make a correlation between the input parameter and output responses with the help of ANOVA, p-value and F-value tests. The tabular and graphical results in terms of skin friction coefficients and Nusselt number against a wide range of physical parameters are performed and displayed.