Conical pin fins significantly enhance heat transfer through optimized flow dynamics and increased surface area. This study provides a detailed analysis of rate of thermal transfer and temperature profile of a conical pin fin constructed from a functionally graded material (FGM) with linear, quadratic, and exponential profiles, and the fin is infused with a trihybrid nanofluid comprising MWCNT, silver, and copper in an \(EG-{H}_{2}O\) base fluid. The governing equation after being nondimensionalized was solved by employing the efficient Fibonacci wavelet technique. This approach facilitated a thorough investigation of the key parameters including the Peclet number, the generation number, the convection parameter, the radiation parameter, power index, thermogeometric parameter, the internal heat generation parameter, and the wet parameter. The results indicate that a 100% increase in the inhomogeneity coefficient (grading parameter) significantly enhances thermal profiles, raising temperatures by 4.8, 4.3, and 6.5% for the linear, quadratic, and exponential FGM profiles, respectively. Furthermore, a 400% elevation in internal heat generation levels induces a proportional rise in fin temperature, with increases of 3, 3.1, and 2.5% for the linear, quadratic, and exponential FGM profiles, respectively. A critical analysis of contour plots for the heat transfer rate reveals that each FGM distribution exhibits distinct characteristics. The exponential profile provides the highest thermal performance and the most favorable temperature distribution, thereby offering significant benefits for applications in electronics cooling, heat exchangers, and aerospace systems.
