PERFORMANCE EVALUATION USING EXERGY ANALYSIS - APPLICATION TO WIRE-COIL INSERTS IN FORCED-CONVECTION HEAT-TRANSFER

Performance of several wire-coil inserts in augmentation of convective heat transfer has been studied. A performance evaluation method based on exergy analysis has been used. The heat transfer and flow-friction characteristics which are necessary for exergy analysis are obtained experimentally. It is seen that the minimum exergy destruction criterion results in a thermodynamically optimum choice. However, heat transfer improvement number and exergy destruction number provide realistic criteria for comparing the performance of augmentation devices. Results of the performance evaluation for 12 different wire-coil inserts with d/D = 0.058-0.113 and p/D = 0.202-0.605 are presented in turbulent flow regions for Re = 30 000-120 000.