The applications of incorporating hybrid nanofluid peristaltic flows span numerous fields and industries such as biomedical and environmental applications, energy systems, and industrial processes, offering significant improvements in heat transfer. In light of this, a comprehensive study is formulated using the Casson non-Newtonian fluid model to examine blood flow behavior in a peristaltic symmetrical channel. This study presents a novel mathematical model of a ternary hybrid nanofluid, comprising three distinct nanoparticles, gold \((Au)\) , iron oxide \((F{e}_{2}{O}_{3})\) , and single-walled carbon nanotubes ( \(SWCNTs\) ) suspended in blood. Additionally, energy dissipation during fluid motion is evaluated by incorporating the effects of viscous dissipation. The influence of non-isothermal properties, including temperature-dependent viscosity, thermal conductivity, and heat source/sink effects is considered to assess their impact on fluid flow. A suspension of \(Au\) , \(F{e}_{2}{O}_{3}\) , and \(SWCNTs\) nanoparticles are introduced into the base fluid to enhance thermal performance. The governing equations are formulated using Cartesian coordinates under the assumptions of a low Reynolds number and long wavelength approximation. The resulting nonlinear coupled equations are solved numerically using the ND Solve scheme in MATHEMATICA based on built-in shooting technique. The study investigates the impact of various parameters on flow dynamics through graphical and tabular analyses, comparing trihybrid nanofluids \((Au+{Fe}_{3}{O}_{4}+SWCNTs)\) with conventional nanofluids \((Au)\) . The temperature-dependent thermal conductivity of ternary hybrid nanofluid is adjusted to evaluate its effect on fluid flow and heat transfer rates. Accordingly, a comparative assessment of heat transfer rates for ternary hybrid nanofluids with both constant and variable thermal conductivities is presented. The findings demonstrate enhancement in heat transfer performance with the use of variable thermal conductivity when compared to the constant thermal conductivity, resulting in an increase of about \(128.5\%\) for a Casson fluid parameter \(\beta\) of \(0.1\) . Likewise, the heat transfer rate of ternary hybrid nanofluid rises by \(0.4\%\) when the viscosity parameter changes from \(0.00\) to \(0.06\) . Furthermore, ternary hybrid nanofluids improve thermal conductivity while simultaneously reducing both velocity and temperature when compared to the nanofluid. Also, throughout the temperature distribution, the viscosity of ternary hybrid nanofluid is \(29.2\%\) , while the thermal conductivity is 33.4% higher than that of the nanofluid.
