THEORETICAL-STUDY OF PERIODIC TURBULENT FORCED-CONVECTION INSIDE A PARALLEL-PLATE CHANNEL

This study analyses the transient conjugated heat transfer in turbulen t duct flow, subjected to sinusoidally varying inlet temperature. A bo undary condition accounts for the effects of external convection. Wail thermal capacitance and transverse heal conduction in the wall are co nsidered. The results obtained with a usual turbulent model which intr oduces the thermal eddy diffusivity together with the velocity profile s are compared with the elementary quasi-steady approach which employs a classical heat transfer coefficient at interface liquid-solid. It i s concluded that for the smaller values of inlet frequency, the quasi- steady approach is able to predict the temperature behaviour inside th e channel, but for higher frequencies this model becomes inadequate. ( C) 1998 Elsevier Science Ltd. All rights reserved.