The continuous improvement of engine performance, combined with strict environmental and safety regulations and the reduction of time and cost of new products, is the major goal of the turbomachinery industry. Particular attention is being focused on the reduction of internal losses and weight, associated with the internal air system. The cooling air is normally bled by holes in the rotor from the main flow of the HP compressor, transported radially inwards towards the shaft and further transferred to the hot parts of the engine. The radial inflow creates vortices induced by the core rotation ratio, which create very high pressure losses and restrict the maximum cooling flow rate. The pressure loss depends strongly on the rotating speed and the mass flow rate. The vortex reducer prevents the development of vortices and therefore reduces the pressure loss. A key area of concern is to optimize the pressure loss concurrent with the use of new light weight or easy to manufacture configurations of vortex reducers. The material presented in this paper describes an experimental study, concentrating on a two cavity test rig for different internal cooling flow concepts. The test rig has steel discs, operating at engine representative flow and temperature conditions and permits several flow and heating modes with axial or/and radial flow configurations. The present work investigates the fluid flow for different vortex reducer configurations at different rotational speeds and its influence on the pressure loss. Particular attention was paid to the influence of size and location of the tubes. The experimental setup and the results concerning the pressure losses for the different configurations are presented.Copyright © 2008 by ASME