Numerical investigation of unsteady Maxwell nanofluid flow over a stretching cylinder with coupled heat and mass transfer

The purpose of this study is to examine the unsteady magnetohydrodynamic flow along with the heat and mass transfer behavior of a bioconvective Maxwell nanofluid past a stretching cylinder, considering the combined influences of Joule heating, thermal and solutal slip, thermal radiation, and activation energy. The importance of this study lies in clarifying how nanoparticle transport, viscoelasticity, motile microorganisms, and magnetic heating jointly affect the momentum, thermal, solutal, and microorganism transport, a subject of relevance to advanced thermal and mass transfer systems. The viscoelastic aspect of the fluid is explained by the Maxwell fluid model, whilst Brownian motion and thermophoretic diffusion of nanoparticles are taken into consideration by the Buongiorno model. Bioconvection caused by motile microorganisms is included in order to increase nanoparticle dispersion and suspension stability. The multistep Milne’s predictor and corrector scheme on the MATLAB software is used to solve the governing nonlinear partial differential equations numerically after they have been converted into nonlinear ordinary differential equations using the proper similarity transformations. The impact of emerging factors on velocity, concentration, temperature, and motile microbe density is studied, as well as the numerical significance of the skin friction coefficient, density number of motile microorganisms, Sherwood number, and Nusselt number. The findings indicate that the decrease in velocity distribution is noted for higher values of the curvature parameter, Maxwell fluid parameter, Hartmann number, and viscosity coefficient, and the Rayleigh number, whereas the increment in the velocity profile is observed due to the mixed convection parameter. The temperature distribution is enhanced due to an increment in the viscosity parameter, Hartmann number, thermophoretic parameter, Maxwell fluid parameter, Brownian motion, Eckert number, and thermal radiation parameter, whereas the thermal slip coefficient significantly drops the temperature distribution. The concentration distributions increase as a result of the viscosity coefficient and decrease because of the solutal slip parameter. The distribution of motile microorganisms increases as the bioconvection Rayleigh number rises but declines with higher magnitude of the bioconvection Lewis number Peclet number, motile parameter, and mixed convection parameter.