Validation of a Two-Phase CFD Air/Mist Film Cooling Model With Experimental Details—Part II: Computational Model Validation

Abstract

In this Part II of the paper, a numerical study has been performed to validate the multiphase computational fluid dynamics (CFD) model by comparing its results to the experimental data of an air/mist film cooling study presented in Part I. The complete experimental test section was simulated including all the details such as five holes, side walls effect, partially opened top wall, the conjugate bottom wall, the initial droplet distributions from the actual data, and the long boundary layer developing region upstream of the cooling holes. The effects of different particle distributions, the breakup and coalescence models, and the conjugate wall on the adiabatic film cooling effectiveness were investigated. The multiphase CFD model employs an Eulerian–Lagrangian approach. The Eulerian method is used for the continuous phase including air and water vapor, and the Lagrangian method in terms of the discrete phase model (DPM) is used to simulate the dispersed phase of liquid droplets in a continuous phase of air–water vapor mixture. The overall consistency between the computational prediction and experimental data is within 0.2% for the air-only case and 7% for the mist case. The results showed that considering the wall using the conjugate heat transfer technique significantly provided better agreement with the experimental data than without including the wall. The non-uniform particle distribution provided better agreement with the experimental results near the film cooling hole exit.