Numerical Simulation of Falling Film Flow Behavior and Heat Transfer Characteristics of Polymer Fluids with Temperature-Dependent Viscosity on Vertical Heated Walls

The nonuniform viscosity of polymer fluids significantly affects flow dynamics and heat transfer in falling film systems. This study systematically investigates the falling film flow and heat transfer behavior of high-viscosity polymer fluids along heated vertical walls, with a focus on temperature-dependent viscosity effects. A temperature-viscosity model was established based on rheological experiments and the Arrhenius equation. Results indicate that viscosity decreases by 58% at 1 mm from the heated wall, forming a pronounced viscosity gradient within the liquid film, reducing the average film thickness by 18%, and enhancing the heat transfer rate. The corrugated wall induces periodic variations in film thickness and enhances heat transfer by promoting localized thinning and increasing the thermal contact area. This study highlights the coupled effects of temperature gradients and viscosity evolution on film flow and heat transfer, providing theoretical support for the efficient control and optimization of high-viscosity polymer fluids in thermal processes.