Stagnation point flow of a Casson nanomaterial with the Cattaneo–Christov dual diffusion and motile micro-organism past a porous vertical sheet causing an entropy generation

• Published in: Pramāṇa Vol. 99; no. 3
• Main Authors: Ali, Farhan, Faizan, M, Zafar, S S, Khan, M Ijaz, Abdullaeva, Barno Sayfutdinovna
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 25.06.2025; Springer Nature B.V
• Subjects: Astronomy; Astrophysics and Astroparticles; Chemical reactions; Convective flow; Entropy; Flow equations; Fluid flow; Fluid friction; Mass transfer; Mass transport; Microorganisms; Nanomaterials; Observations and Techniques; Physical factors; Physics; Physics and Astronomy; Porous media flow; Radiation; Rheological properties; Rheology; Stagnation point; Thermal radiation; Transmutation; Transport phenomena; Velocity distribution; 76.S.xx; 76.A.05; Bioconvection flow; Nanofluid; entropy generation; stagnation point; Casson flow
• DOI: 10.1007/s12043-025-02904-9
• ISSN: 0973-7111; 0304-4289

The current investigation is carried out to study the mixed convective stagnation point flow of Casson nanomaterial comprising gyrotactic micro-organisms over a vertical porous sheet. The Casson fluid flow equation gives details about fluid rheology. The proposed Cattaneo–Christov dual diffusive theory is intended to explore the thermal and mass characteristics. Micro-organisms’ irreversible heat transport, mass transport and fluid friction formulate the entropy generation. Moreover, the heat radiation, heat source and chemical reaction have been computed for the heat and mass. The heat transport phenomena are used to account for convective flow conditions. The constitution equations are adapted into a system of dimensionless equations through the appropriate transmutation. The dimensionless equations have been solved using the homotopic approach, a semi-analytical technique. Tables and graphs are additionally employed for addressing the behaviour of additional physical factors of pursuit, including mass transfer rate, heat transport, velocity field, the density of the motile gyrotactic bacteria, entropy generation and Bejan number. The porosity variable and the bioconvection Raleigh number reduce the velocity field. The heat radiation has an intensifying effect on the thermal field. The concentration profile is noted to diminish as the magnitude of the chemical reaction and Brownian motion enhance. The entropy generation and Bejan number increase with the increment values of the Brikmann number. Our established approach to mixed convection is supported by computations that have been thoroughly validated by comparing our results with previously published literature.