Bhumavarapu Venkateswarlu

Hybrid nanofluids exhibit outstanding cooling capabilities in elevated temperature settings, rendering them ideal for numerous thermal applications. Their efficiency encompasses fields such as cooling for electronic devices, heat exchangers, the manufacturing and automotive sectors, heat pipes, and solar power systems. The novelty of this research lies in the entropy analysis of the unsteady 2D flow of an EMHD Casson (GO‐MoS ₂ /C ₂ H ₆ O ₂ ‐H ₂ O) HNF moving over a porous stretching surface while incorporating the effects of chemical reactions and electrical Joule heating. The nonlinear PDEs are transformed into a system of ODEs using similarity transformations and subsequently solved numerically via the KB method in MATLAB. Further, a statistical approach is applied to optimise HT using RSM with central composite design. The research assesses the effects of essential factors on the flow profiles and entropy generation, along with their relevance in engineering applications. The results found that an elevation in the magnetic field and Casson parameters diminishes the nanofluid velocity, while a robust electric field amplifies it in HNF. The temperature of HNF rises with elevated radiation and Eckert number, whereas the NF concentration diminishes as the chemical reaction parameter increases. The entropy rises significantly for the HNF as the Casson fluid, radiation parameters, and Brinkman number increase, whereas the Bejan number diminishes with the same influencing factors. An elevation in the Casson fluid parameter boosts skin friction by 3.52% more in HNFs, while an increase in the electric field parameter diminishes it by 2.25% further in conventional NFs. The Nusselt number experiences a further decrease of 3.4% in NFs as the radiation parameter rises, whereas it exhibits an increase of 2.1% in HNFs with an escalating Biot number. An elevation in the chemical reaction parameter results in a boost in the Sherwood number, with a 2.8% more significant impact noted in HNFs owing to their exceptional transport characteristics. Furthermore, the RSM incorporates the key factors influencing the Nusselt number into a quadratic regression model, which demonstrates excellent predictive capability, as evidenced by an R ² value of 98.97%.

This research explores entropy generation in the two‐dimensional flow of MHD (Al₂O₃–TiO₂/H₂O) hybrid nanofluid over an exponentially stretching sheet within a porous medium. The study incorporates chemical reaction, thermal radiation, and Joule heating into the concentration and energy equations, which are thoroughly analyzed. The governing PDEs are transformed into nonlinear ODEs using similarity solutions and solved numerically with the bvp4c solver in MATLAB. The study examines the effects on flow profiles and key engineering parameters. Results show that increasing Brinkman and Reynolds numbers produces contrasting trends in entropy generation and the Bejan number. A stronger magnetic field and porous medium increase skin friction by 2.18 % in hybrid nanofluids. An enhanced Eckert number combined with radiation raises heat transfer by 5 % compared to conventional TiO₂/H₂O. The mass transfer rate increases by over 1.5 % with a rising reaction factor in Al₂O₃–TiO₂/H₂O.

Ternary nanofluids demonstrate better heat transfer characteristics in contrast to conventional liquids and typical hybrid nanofluids. These are applied in sophisticated cooling systems for electronics, heat exchangers, and automotive engines, along with renewable energy systems such as solar collectors, where efficient heat transfer plays a crucial role. The aim of this research is to investigate the movement of a Casson ternary nanofluid passing through a bidirectional exponential sheet by employing the innovative Cattaneo-Christov heat flux concept. The utilization of the energy equation considers thermal radiation, viscous dissipation, and heat source/sink effects, with the integration of chemical reaction effects into the concentration equation. An analysis of entropy generation is utilized to evaluate the thermodynamic irreversibility within the system. The conversion of transport equations involves a transformation from partial to ordinary differential equations, followed by a numerical solution utilizing the BVP4C solver embedded in the MATLAB package R2022b. The impacts of developed factors on thermal, concentration, and velocity behavior, as well as engineering quantities, are thoroughly explored graphically. The outcome reveals that the velocity gradients diminish as magnetic fields intensify, while it amplified by the Hall factor. The rise in temperature of ternary nanofluid correlates with elevated levels of radiation, and Brownian motion. Concentration intensifies with the rapid development of thermophoresis influences. Heightened values of the Reynolds and Brinkman numbers give rise to amplified entropy production but a decrease in the Bejan number. The ternary nanofluid displays a remarkable 8.92% increase in skin friction on the x-axis and y-axis, influenced by the potent Darcy-Forchheimer factor. The rates of mass and heat transfer in nanofluids undergo a decrease of 8.58% and 12.52%, respectively, due to the heightened influence of Brownian motion and Eckert number. The results could provide valuable insights into the performance of ternary nanofluids in various industrial environments under specific conditions.