Applications: The nanofluids and their upgraded version (ternary and tetra nanofluids) have a very rich thermal mechanism and convinced engineers and industrialist because of their dominant characteristics. These broadly use in chemical, applied thermal, mechanical engineering, and biotechnology. Particularly, heat transfer over a cylindrical surface is important in automobiles and heavy machinery. Purpose and Methodology: Keeping in front the heat transfer applications, a model for Tetra-Composite Nanofluid [(Al₂O₃-CuO-TiO₂-Ag)/water]_tetra is developed over a vertically oriented cylinder in this study. The existing traditional model was modified with innovative effects of nonlinear thermal radiations, magnetic field, absorber surface of the cylinder, and effective thermophysical characteristics of tetra nanofluid. Then, a new heat transfer model was achieved successfully after performing some mathematical operations. Major Findings: The mathematical analysis was performed via RK and determined the results graphically. The study gives suitable parametric ranges for high thermal efficiency and fluid movement. Applied magnetics forces were observed excellent to control the fluid motion, whereas curvature and buoyancy forces favor the motion. Thermal mechanism in Tetra nanofluid is dominant over ternary nanoliquid and nonlinear thermal radiations increased the heat transfer rate.

Comparative heat transfer analysis in conventional (Al₂O₃-CuO/H₂O)_hnf and modified hybrid nanofluid known as ternary hybrid nanofluid (Al₂O₃-CuO-Cu/H₂O)_mhnf is one of the potential topics of interest and is the demand of modern technological world to cope with the heat transfer problems faced by the industrialists and engineers. Therefore, the study is organized for hybrid and tri-hybrid nanofluids for their thermal storage. To improve thermal energy storage in the above-mentioned fluids, novel effects of a uniform magnetic field, convective heat transfer mode, and newly developed empirical correlations are used to synthesize tri-hybrid nanofluids. The comparative analysis under various physical constraints reveals that tri-hybrid nanoliquids have ultra-high thermal efficiency than conventional nanoliquids. Therefore, these fluids are very beneficial for industrial uses more specifically for purification purposes or where ultra-high heat transfer is required to accomplish the process.

The heat transfer remains a huge problem for industrialists and engineers because many production processes required considerable amount of heat to finish the process successfully. Although, conventional fluids have large scale industrial applications but unable to provide huge amount of heat transfer. Therefore, the study is organized to propose a new ternary heat transfer model using different physical constraints. The key applications area of nanofluid heat transfer are chemical, applied thermal and food processing engineering. and Methodology: The key purpose of this research is introduce a new ternary nanofluid model using the impressive effects of thermal radiations, surface convection and saddle/nodal points. The results simulated via RKF-45 and discussed in detail. The strength of Al₂O₃ nanoparticles form 1%–7% (keeping fixed CuO and Cu as 4% and 6%) and s₁ = −0.2,-0.4,-0.6,-0.8 controlled the fluid movement while s₁ = 0.2,0.4,0.6,0.8 boosted the velocity. Increasing the convection process B_i = 0.1,0.2,0.3,0.4 increased the temperature significantly. Further, shear drag is maximum for ternary nanofluid and thermal radiations R_d = 0.1,0.2,0.3,0.4 enhances the heat transfer rate.