Heat‐Transfer Impact on Unsteady Boussinesq–Stokes CNT Nanofluid Flow Over Stretching/Shrinking Surface Using Analytical Method

ABSTRACT

This work investigates the unsteady stagnation‐point flow over a permeable stretching/shrinking surface of a Boussinesq–Stokes suspension nanofluid comprising carbon nanotubes (SWCNT and MWCNT). Carbon nanotubes (CNTs) are widely used in nanofluids, electronics, and biomedical engineering due to their excellent thermal, electrical, and mechanical capabilities. Thermal radiation and convective boundary conditions are included in the study to examine heat‐transfer properties. Appropriate similarity transformations are used to convert the governing nonlinear partial differential equations into a system of nonlinear ordinary differential equations. The temperature distribution is described using the incomplete gamma function after the ensuing equations are solved analytically. The analytical solutions for velocity and temperature across several parameters are presented in graphs. The findings show that while the temperature distribution increases with greater Biot number, radiation parameter, and nanoparticle volume fraction, increases in the mass‐transpiration parameter and the couple‐stress parameter considerably lower the velocity profile. Additionally, the thermal performance is improved by the presence of CNTs, with MWCNT‐based nanofluid showing better heat‐transfer properties than SWCNTs. The study also discovers dual solutions under specific parametric conditions, illustrating the flow system's complexity.