Experimental Investigation of Flow within a Rotor Stator Cavity

Authors

M. Micio - Ergon Research S.r.l., Italy
D. Massini - Department of Industrial Engineering, University of Florence, Italy
B. Facchini - Department of Industrial Engineering, University of Florence, Italy
F. Bavassano - A.S.EN Ansaldo Sviluppo Energia, Italy
M. Mantero - A.S.EN Ansaldo Sviluppo Energia, Italy

Abstract

Reliable design of secondary air system is one of the main tasks in order to ensure safety, unfailing and performance of gas turbine engines. To meet the increasing demands of gas turbines design, improved tools in prediction of the secondary air system behaviour over a wide range of operating conditions are needed. The state of the art of the fluid solver tools used to predict the flow path inside cavities is generally based on codes with correlative approaches, in order to reduce calculation times and computational resources. To improve the prediction capabilities of a simple one-dimensional model based on correlations, the authors performed an experimental investigation on a novel test rig composed by a rotating disc facing a flat stator. Imposing several working conditions it was possible to investigate a wide range of flow regime inside the rotor-stator cavity. Rotational velocity was varied in order to gain a rotational Reynolds number up to 1.2 · 106 , different sealing mass flows were injected within the cavity reaching a maximum turbulent flow parameter of 0.2. Analysis of swirl development was performed by means of radial distribution of static and total pressure probes, a torque-meter was used to evaluate the frictional momentum exerted by the rotor on the fluid. In this paper, the comparisons between experimental data and published correlations are shown to validate the experimental procedure and the postprocessing. This rig will be used for future investigation on flow field using PIV technique and heat transfer analysis on the stator using TLC with steady state tests.