Scaling of Film Cooling Performance From Ambient to Engine TemperaturesSource: Journal of Turbomachinery:;2015:;volume( 137 ):;issue: 007::page 71007DOI: 10.1115/1.4029197Publisher: The American Society of Mechanical Engineers (ASME)
Abstract: The present study employs computational fluid dynamics (CFD) to explore the complexities of scaling film cooling performance measurements from ambient laboratory conditions to high temperature engine conditions. In this investigation, a single shaped hole is examined computationally at both engine and near ambient temperatures to understand the impact of temperature dependent properties on scaling film cooling performance. By varying select flow and thermal parameters for the low temperature cases and comparing the results to high temperature flow, the parameters which must be matched to scale film cooling performance are determined. The results show that only matching the density and mass flux ratios is insufficient for scaling to high temperatures. In accordance with convective heat transfer fundamentals, freestream and coolant Reynolds numbers and Prandtl numbers must also be matched to obtain scalable results. By virtue of the Prandtl number for air remaining nearly constant with temperature, the Prandtl number at ambient conditions is sufficiently matched to engine temperatures. However, laboratory limitations can prevent matching both the freestream and coolant Reynolds numbers simultaneously. By examining this tradeoff, it is determined that matching the coolant Reynolds number produces the best scalability. It is also found that by averaging the adiabatic effectiveness of two experiments in which the freestream and coolant Reynolds number are matched, respectively, results in significantly better scalability for cases with a separated coolant jet.
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contributor author | Greiner, Nathan J. | |
contributor author | Polanka, Marc D. | |
contributor author | Rutledge, James L. | |
date accessioned | 2017-05-09T01:24:37Z | |
date available | 2017-05-09T01:24:37Z | |
date issued | 2015 | |
identifier issn | 0889-504X | |
identifier other | turbo_137_07_071007.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl/handle/yetl/159943 | |
description abstract | The present study employs computational fluid dynamics (CFD) to explore the complexities of scaling film cooling performance measurements from ambient laboratory conditions to high temperature engine conditions. In this investigation, a single shaped hole is examined computationally at both engine and near ambient temperatures to understand the impact of temperature dependent properties on scaling film cooling performance. By varying select flow and thermal parameters for the low temperature cases and comparing the results to high temperature flow, the parameters which must be matched to scale film cooling performance are determined. The results show that only matching the density and mass flux ratios is insufficient for scaling to high temperatures. In accordance with convective heat transfer fundamentals, freestream and coolant Reynolds numbers and Prandtl numbers must also be matched to obtain scalable results. By virtue of the Prandtl number for air remaining nearly constant with temperature, the Prandtl number at ambient conditions is sufficiently matched to engine temperatures. However, laboratory limitations can prevent matching both the freestream and coolant Reynolds numbers simultaneously. By examining this tradeoff, it is determined that matching the coolant Reynolds number produces the best scalability. It is also found that by averaging the adiabatic effectiveness of two experiments in which the freestream and coolant Reynolds number are matched, respectively, results in significantly better scalability for cases with a separated coolant jet. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | Scaling of Film Cooling Performance From Ambient to Engine Temperatures | |
type | Journal Paper | |
journal volume | 137 | |
journal issue | 7 | |
journal title | Journal of Turbomachinery | |
identifier doi | 10.1115/1.4029197 | |
journal fristpage | 71007 | |
journal lastpage | 71007 | |
identifier eissn | 1528-8900 | |
tree | Journal of Turbomachinery:;2015:;volume( 137 ):;issue: 007 | |
contenttype | Fulltext |