Thermodynamic and hydrodynamic analysis in double-diffusive mixed convection flow: Impact of dual cylindrical obstacles in a wavy channel
Shafqat Hussain, A.K. Chattopadhyay, Awatef Abidi, Samrat Hansda
Abstract
This study presents an extensive numerical analysis of double-diffusive mixed convection flow in a porous wavy-walled channel containing two cylindrical obstacles, focusing on the combined effects of obstacle-induced flow disturbances, magnetic fields, and porous medium properties on heat and solute transport. An expanded Darcy–Brinkman technique is used to simulate the porous medium in order to precisely represent flow resistance in this intricate geometry. Key objectives include analyzing the influence of flow parameters and obstacle spacing on vortex dynamics, thermal and solutal transport, as well as hydrodynamic forces characterized by drag coefficient (CD), lift coefficient (CL), and pressure differences (ΔP). Results show that increasing the Reynolds number strengthens vortex structures, enhancing Nuavg and Shavg. Although increasing porosity from 0.4 to 1 at Da=10−4 yields slight improvements (0.49% and 0.54%, respectively), the changes are minimal. In contrast, increasing the Darcy number from 10−4 to 10−1 at fixed ϵ=0.4 leads to notable reductions in Nuavg (8.9%) and Shavg (14.7%) due to weakened convective transport. Wider cylinder spacing reduces wake interference and enhances vortex shedding, improving convective efficiency. Thermophysical parameters—such as increasing Pr from 0.7 to 1.0—yield a 14.9% increase in Nuavg, while a rise in the Dufour number from 0 to 0.5 boosts it by 34.7%. Similarly, Shavg improves by 61.2% as the Lewis number increases from 1 to 10. These findings suggest that tailored parameters can optimize thermo-solutal transport and flow, benefiting applications like electronic cooling, geothermal systems, and chemical reactors.