Aerothermal Analysis of a Turbine Casing Impingement Cooling System

Soghe, Riccardo Da; Facchini, Bruno; Micio, Mirko; Andreini, Antonio

doi:10.1155/2012/103583

Cited by 7 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are several challenges in the LPTACC traditional design, spanning from the impingement holes discharge behavior to the impingement jet heat transfer performance. Interesting discussions on this can be found in Da Soghe et al [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Development of Experimental and Numerical Methods for the Analysis of Active Clearance Control Systems1

Soghe

Mazzei

Tarchi

et al. 2021

Journal of Engineering for Gas Turbines and Power

Self Cite

View full text Add to dashboard Cite

The ever increasing performance requirements of modern aeroengines necessitate the development of effective ways to improve efficiency and reduce losses. Casing temperature control is particularly critical from this point of view, since thermal expansion directly affects the blade tip clearance and thus the associated leakages. To limit the turbine tip flows, active clearance control (ACC) systems have been implemented over the last decades. These systems are usually based upon impingement cooling, generated by a series of perforated manifolds enclosing the turbine casing. When dealing with aeroengine low pressure turbines, the current trend in increasing the engine bypass ratio, so as to enhance the system propulsive efficiency, pushes the limits of ACC traditional design performance. The reduction of the pressure head at the ACC system inlet requires lower nozzle-to-target distances as well as denser impingement arrays to compensate the reduction of the jets' Reynolds number. Literature correlations for the impingement heat transfer coefficient estimation are then out of their confidence range and also RANS numerical approaches appear not suitable for future ACC designs. In this work, methodologies for the development of accurate and reliable tools to determine the heat transfer characteristics of low pressure ACC systems are presented. More precisely, this paper describes a custom designed finite difference procedure capable of solving the inverse conduction problem on the target plate of a test sample. The methodology was successfully applied to an experimental setup for the measurement of the thermal loads on a target plate of a representative low pressure ACC impinging system. The experimental outcomes are then used to validate a suitable numerical approach. Results show that RANS model is not able to mimic the experimental trends, while scale-resolving turbulence models provide a good reconstruction of the experimental evidences, thus allowing to obtain a correct interpretation of flow and thermal phenomena for ACC systems.

show abstract