Flow and heat transfer over a permeable moving wedge in a hybrid nanofluid with activation energy and binary chemical reaction

Purpose The analysis of boundary layers is needed to reflect the behaviour of fluid flows in current industrial processes and to improve the efficacy of products. Hence, this study aims to analyse the flow and heat transfer performance of hybrid alumina-copper/water (Al2O3-Cu/H2O) nanofluid with the inclusion of activation energy and binary chemical reaction effect towards a moving wedge. Design/methodology/approach The multivariable differential equations with partial derivatives are converted into a specific type of ordinary differential equations by using valid similarity transformations. The reduced mathematical model is elucidated in the MATLAB system by using the bvp4c procedure. This solution method is competent in delivering multiple solutions once appropriate assumptions are supplied. Findings The results of multiple control parameters have been studied, and the findings are verified to provide more than one solution. The coefficient of skin friction was discovered to be increased by adding nanoparticles volume fraction from 0% to 0.5% and 1%, by almost 1.6% and 3.2%. Besides, increasing the nanoparticles volume fraction improves heat transfer efficiency gradually. The inclusion of the activation energy factor displays a downward trend in the mass transfer rates, consequently reducing the concentration profile. In contrast, the increment of the binary reaction rate greatly facilitates the augmentation of mass transfer rates. There is a significant enhancement in the heat transfer rate, approximately 13.2%, when the suction effect dominates about 10% in the boundary layer flow. Additionally, the results revealed that as the activation energy rises, the temperature and concentration profiles rise as well. It is proved that the activation energy parameter boosts the concentration of chemical species in the boundary layer. A similar pattern emerges as the wedge angle parameter increases. The current effort aims to improve the thermal analysis process, particularly in real-world applications such as geothermal reservoirs, chemical engineering and food processing, which often encountered mass transfer phenomenon followed by chemical reactions with activation energy. Originality/value The present results are original and new for the study of flow and heat transfer over a permeable moving wedge in a hybrid nanofluid with activation energy and binary chemical reaction.

Suction and Injection Impacts On Casson Nanofluid with Gyrotactic Microorganisms Over a Moving Wedge

The present work deals with the effects of suction and injection on Casson nanofluid around a moving wedge under the influence of gyrotactic microorganisms along with viscous & ohmic dissipation. The governing system of highly coupled nonlinear PDEs together with assisting boundary conditions are converted by applying suitable similarity transformations, into a set of non-linear ODEs. The obtained flow model is solved numerically by bvp4c (MATLAB) procedure. The accuracy of the flow model under consideration is validated by employing another well-known mathematical technique Runge-Kutta-Fehlberg (RKF) having good agreement while comparing the numerical results obtained by bvp4c for both suction & injection cases. Impacts of various pertinent parameters active in the flow model such as thermophoresis and Brownian motion, moving wedge, magnetic field, viscous and ohmic dissipation are numerically calculated for both suction & injection flow situations and also presented graphically. It is observed that the increase in casson parameter enhances the velocity but declines the density of motile organism, concentration and temperature for suction as well as injection flow case. The impacts of mass transfer rate of gyrotactic microorganisms, Nusselt and Sherwood numbers for various fluid parameters are numerically presented in tabular form, separately for both suction and injection. One of the important observation of the current study is that the suction or injection plays a key role in controlling boundary layer flow and brings stability in the flow. Moreover, rate of heat & mass transfer get enhanced in the existence of gyrotactic microorganisms. Further, it would be worth mentioning that physical behavior of this flow problem coincide very well with already published literature either graphical or in tabular representation.