For simplified calculation of heat transfer with viscous heat generation

the tangential flow of polymer melt in a cylindical annular space was transformed into drag-flow between two parallel plates by using the finite difference method. The longitudinal Temperature distribution and the temperature gradients at the surfaces of the plates was derived. The local Nu-sselt Number and the local heat transfer coefficient at the plate surfaces can thus be calculated. The calculated results show that the average melt temperature Ts rises gradually along the cylinder length

and the rate of temperature rise diminished slowly until it approaches zero. Typically a length of 27.72 meters is required for obtaining a fully developed temperature profile. Approximate methods for heat transfer calculation are suggested for viscous heat generation in polymer processing installations such as screw extruder

shear head

run-of-the-mold cavity

etc.