This research article focuses on analyzing thermal characteristics in a permeable conduit with expanding walls using Casson magnetohydrodynamic (MHD) nanofluids. The nanofluid used is an incompressible mixture of Copper (Cu) nanoparticles in water. To simplify the problem, the governing equations with partial derivatives are transformed into ODEs through appropriate similarity transformations. These resulting nonlinear ordinary differential equations are then computed by numerical simulation employing the Runge-Kutta method with the shooting technique. The study reveals that various factors, such as nanoparticle volume fraction, Casson fluid parameter, Reynolds number, magnetic field strength, and Prandtl number, have significant effects on the velocity(momentum) and the temperature(energy) distribution, characteristics within the channel.