Two dimensional unsteady stagnation point flow of Casson hybrid nanofluid over a permeable flat surface and heat transfer analysis with radiation

• Published in: Journal of the Taiwan Institute of Chemical Engineers 2021-10, Vol.127, p.79-91
• Main Authors: Anusha, T., Huang, Huang-Nan, Mahabaleshwar, U.S.
• Format: Article
• Language: English
• Subjects: Casson fluid parameter; Hybrid nanofluid; Inclined MHD; Mass transpiration; Radiation parameter; Unsteady stagnation point flow
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2021.08.014

•HNF flow and heat transfer over stretching/shrinking sheet for unsteady case is studied.•The analytical solutions are obtained for velocity and temperature in terms of exponential.•The conditions of upper branch and lower branch solutions are obtained.•The velocity boundary layer thickness is less for more value of VC.•Radiation number increases the thermal boundary-layer thickness. The inclined magnetohydrodynamic (MHD) unsteady flow and heat transfer of Casson hybrid nanofluid (HNF) due to porous stretching sheet is investigated. In the present paper we analyze the Casson fluid unsteady flow over permeable flat plate in the presence of inclined magnetic field and heat transfer of fluid with the effect of thermal radiation. The conservation of mass, conservation of momentum and thermal equations are non-dimensional into the system of nonlinear ODEs by taking the suitable similarity transformation. An exact analytical solution is obtained for velocity. The energy equation in the presence of inclined magnetic field and radiation is a differential equation with variable coefficients, which is transformed to an incomplete gamma function using a new variable and using the Rosseland approximation for the radiation. The governing differential equations are solved analytically and the effects of various parameters on velocity profiles, skin friction coefficient, temperature profile and wall heat transfer are presented graphically. There is an enhancement in heat transfer and pressure drop by usage of HNF. The variations in velocity and temperature profiles with respect to different various pertinent physical parameters. An increase of the mass transpiration (suction) parameter intensity increases the skin friction, which consequently improves the heat transfer enhancement and reduces the HNF temperature. Furthermore, the skin friction coefficient increases due to mass suction and MHD in the stretching sheet, whereas the rate of heat transfer decays. The results have possible technological applications in liquid-based systems involving stretchable materials. [Display omitted]