A Method for Conjugate Heat Transfer With Unsteady RANS Simulation

The conjugate heat transfer simulation is expected to simulate precise temperature distributions of turbine cooling structures and contribute to the reduction of cooling air usage. This method has mainly been used to predict steady state temperature because of the large difference of time scale between RANS flow simulation and thermal conduction in solid materials, thus the accuracy of temperature estimation depends on the modeling of the turbulence. Despite many efforts to improve turbulence models, an inherent limitation of RANS and turbulence modeling and the necessity of unsteady simulation for better accuracy in heat transfer simulations have been pointed out. The aim of this study is to combine the unsteady RANS simulation with the steady thermal conduction of solid materials. The “Time Smoothing” method was introduced to compensate the large time scale difference between fluid and solid, then the effectiveness of the method was confirmed through conjugate heat transfer simulations around a pipe shape object where strong flow unsteadiness prevails.Copyright © 2014 by ASME