HEAT-TRANSFER IN A TURBULENT FALLING FILM SUBJECT TO INTENSE VOLUMETRIC HEATING

Heat transfer in a turbulent, incompressible falling liquid film flowi ng over a vertical flat surface, where in addition to a wall heat flux a thin fluid layer adjacent to the surface is subject to intense, vol umetric heating, is modeled. The falling film velocity profile is obta ined by numerically solving the steady-state and quasi fully-developed film momentum conservation equation, using Van Driests's eddy diffusi vity profile, modified for the region near the film surface. The two-d imensional falling film energy conservation equation is numerically so lved. Parametric calculations for the cooling of the Positron Emission Tomography (PET) accelerator target windows are presented. It is demo nstrated that a turbulent falling water film is capable of providing e ffective cooling for the PET window systems.