Combined Experimental and CFD Investigation of Flat Plate Film Cooling through Fan Shaped Holes

Samaneh Rouina,Silvia Ravelli,Giovanna Barigozzi

doi:10.3390/ijtpp4020007

Samaneh Rouina, Silvia Ravelli + Show 1 more

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https://doi.org/10.3390/ijtpp4020007

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Abstract

The present paper reports the results of an experimental and computational investigation of flat plate film cooling jets discharged from three fan-shaped holes. Measurements have been carried out at near unity density ratio in a low-speed wind tunnel, at low inlet turbulence intensity, with blowing ratios (BR) of 1 and 2. Aerodynamic results have shown that the jet stays attached to the flat plate. Thermal measurements have revealed that film cooling effectiveness decreases downstream of the holes, and BR equal to 1 provides the best trade-off between cooling air consumption and thermal protection. Consequently, BR = 1 was selected for assessing the performance of different turbulence models, implemented in STAR-CCM+, according with the steady Reynolds-averaged Navier–Stokes (RANS) approach. Predictions from realizable k-ε (RKE), shear stress transport k-ω (SST KW) and Reynolds stress model (RSM) were compared against measurements of laterally averaged and centerline adiabatic effectiveness, as well as off-the-wall velocity maps and profiles of stress components. RSM provided the most accurate predictions.

Highlights

There is no doubt that film cooling is an integral part of cooling techniques in the gas turbine industry to protect gas turbine components from high turbine inlet temperature
This study revealed that,the in highest case of film shaped holes, there is no production of counterinvestigated the effect of inlet crossflow on cooling performance of a round and fan-shaped hole inclined rotating vortices at the exit so that turbulence peak occurs at the downstream edge of the hole
Tests have been carried out at low speed, about speed, about 15 m/s, and low inlet turbulence intensity level below 1.0%, for blowing ratio (BR) values

Summary

Introduction

There is no doubt that film cooling is an integral part of cooling techniques in the gas turbine industry to protect gas turbine components from high turbine inlet temperature. Of all aspects that influence the film cooling performance, has been extensively studied in the past decades. These studies confirmed the better performance of fan-shaped holes with respect to the cylindrical ones, due to diffusing expansion at the exit of the hole as mentioned by Goldstein et al [1], and Gritsch et al [2]. Porter et al [6] reported the velocity and turbulence data in the near field of round and laterally expanded fan-shaped holes. Their results are consistent with those discussed in [5]. Neither Thole et al [5] nor Porter et al [6] combined thermal and aerodynamic performance of film cooling

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