Heat Transfer and Flow Characteristics in 90 deg Ribbed Duct Using Different Coolants
Several of industrial applications such as electronic devices, heat exchangers, gas turbine blades, etc. need cooling processes. The internal cooling technique is proper to some applications. In the present work, computational simulations were made using ANSYS CFX to predict the improvements of internal heat transfer in rectangular ribbed channel using different coolants. Several coolants such as air, steam, air/mist and steam/mist were investigated. The shear stress transport model (SST) is selected by comparing the predictions of different turbulence models with experimental results. The results indicate that the heat transfer coefficients are enhanced in ribbed channel at injection small amount of mist. The heat transfer coefficients of air/mist, steam and steam/mist increase by 12.5%, 49.5% and 107% than that of air, respectively. Furthermore, comparing with air, the air/mist heat transfer coefficient enhances by about 1.05 to 1.14 times when mist mass fraction increases from 2% to 8%, respectively. For steam/mist heat transfer coefficient increases by about 1.12 to 1.27 times higher than that of steam over the consider range of mist mass fraction.