The bioconvection effects with nanofluid are major application in biofuels. This analysis aimed to observe the bioconvection effect in unsteady two-dimensional Maxwell nanofluid flow containing gyrotactic motile microorganisms across a stretching/shrinking cylinder evaluating the consequences of thermal radiation and activation energy. The Cattaneo-Christov double diffusion theory is also observed. Nanofluids are quickly perceptive into many solicitations in the latest technology. The current research has noteworthy implementations in the modern nanotechnology, microelectronics, nano-biopolymer field, biomedicine, biotechnology, treatment of cancer therapy, cooling of atomic reactors, fuel cells, and power generation. By using the proper similarity transformation, the partial differential equations that serve as the basis for the current study are gradually reduced to a set of highly nonlinear forms of ordinary differential equations, which are then numerically, approached using a well-known shooting scheme and the bvp4c tool of the MATLAB software. Investigated is the profile behavior of the flow regulating parameters for the velocity field, thermal field, and volumetric concentration of nanoparticles and microorganisms. From the results, it is concluded that velocity is reduced with a larger bioconvection Rayleigh number. The thermal field is increased with a larger amount of thermal Biot number and thermal radiation. The concentration of nanoparticles increases with an increment in the thermophoresis parameter. Furthermore, the microorganism’s field is decreased with a larger Lewis number. The findings demonstrate that by optimizing the concentration of nanoparticles and microorganisms, the thermal efficiency of biofuels can be significantly improved. This leads to more sustainable and efficient energy production. By optimizing the concentration of nanoparticles and microorganisms in biofuels, the thermal properties can be significantly improved, leading to more efficient combustion processes. This can reduce the overall cost and increase the yield of biofuels. Improved cooling systems for medical imaging devices such as MRI machines can be developed using nanofluids, ensuring better performance and patient safety.

Purpose: Fluid thermal efficiency is crucial in major industrial sectors. Traditional fluids often lack the heat transmission needed for various operations. To address this, researchers introduced metallic and non-metallic nano additives, creating a new type of fluid called Nanofluid. This article explores the squeezing flow of Casson nanofluid between parallel disks, considering suction/injection, thermophysical impacts, thermal radiation, and chemical reaction. Methodology: The study uses the Buongiorno nanofluid theory to analyze thermophoresis and Brownian motion, reducing partial differential equations to ordinary differential equations. Numerical technique (shooting approach) is employed to solve these equations, and the results are presented graphically. Conclusions: The study reveals that axial velocity decreases as the Casson fluid parameter increases. Near the intersection point of the velocity field with varying magnitudes of the linear thermal convection parameter, radial velocity increases. It is observed that the thermal field intensifies with a higher linear thermal convection parameter. Additionally, elevated values of the thermal radiation parameter lead to an increase in temperature distribution estimates. Applications of Current Model: Casson fluid, classified as a non-Newtonian fluid, exhibits characteristics of both an elastic solid at low shear strain and a Newtonian fluid at high stress. It is characterized by infinite viscosity at zero shear rate and infinite viscosity at infinite shear rate. Examples of Casson fluids in everyday life include tomato juice, human blood, soup, and orange juice.