Numerical computation of turbulent conjugate heat transfer in air heater

The contribution deals with numerical simulation of conjugate heat transfer in air heater of the laundry dryer. The heat transfer consists of internal heat generation in the electrical heating coils, forced convection from the coils to the air and heat conduction through the metal walls of the heater. In order to simplify the computational mesh the porous media concept was used for discretization of electrical coils. A special attention was given to the selection of a turbulence model, capable of accurate solution of conjugate heat transfer. After extensive testings the SST model, used in the numerical code CFX5, was selected. The computational results were compared with results of velocity and temperature measurements on the device in the laundry dryer, and good agreement was observed.