Abstract
The importance of nanoparticles has evolved over the twenty-first century due to crucial applications in numerous thermophysical systems and increased sustainability. Based on improvements, the current work plans to explore Darcy free convection around an isothermal vertical cone with a fixed apex half-angle pointing downward in a nano liquid saturated porous medium. It is considered that the medium consists of oxytactic microorganisms with nanoparticles. The cone is subjected to nanoparticles concentration and oxytactic microorganisms' density. The impacts of Brownian movement and thermophoresis are involved in the model for nanoliquids. Solar radiation and convective heating phenomena are added to the energy equation to increase the thermal distribution phenomena. Zero mass flux phenomena are applied at the boundary. Employing appropriate non-dimensional parameters transforms a system of nonlinear ordinary differential equations. These equations are solved mathematically by the 4th order Runge-Kutta method along with a shooting algorithm. The leading dimensionless parameters, such as velocity, nanoparticles concentration, temperature, oxytactic microorganism's density, and local numbers (Nusselt, Sherwood, density) for microorganisms are examined in detail. Mathematical computation is carried out for different values that define the flow properties. It is observed that nanoparticle concentration diminishes by increasing the Brownian movement. Furthermore, the motile organism profile declines with an increment in bioconvection Lewis number.