This work examines the transient flow and heat transfer characteristics of a Carreau ternary hybrid nanofluid ( \(\hbox {TiO}_2\) + Cu + \(\hbox {Al}_2\hbox {O}_3\) /CMC– \(\hbox {H}_2\) O) across a stretched sheet subjected to combined electromagnetic and thermal influences. The model integrates suction/injection, heat radiation, Ohmic dissipation, and concentration fluctuations, emphasising entropy generation. The governing nonlinear equations are converted using similarity variables and solved numerically using the BVP5c technique. Multiple linear regression is used to forecast skin friction, Nusselt number, and Sherwood number. Results indicate that magnetic and electric field intensities, Weissenberg number, and thermal radiation substantially affect velocity, temperature, and concentration distributions, but entropy production underscores irreversibility processes. The ternary hybrid nanofluid has enhanced thermal performance relative to mono and binary nanofluids, presenting potential advantages for cooling, extrusion, and coating applications.
