A LOW SPEED COMPRESSOR TEST RIG FOR FLUTTER INVESTIGATIONS

Abstract

A test facility for aeroelastic investigations has been set up at the chair of Aero Engines at the Technische Universitat Berlin. The test rig provides data for tool and code validation and is used for basic aeroelastic experiments. It is a low speed wind tunnel which allows free and controlled flutter testing. The test section contains a linear cascade with eleven compressor blades. Nine of them are elastically suspended. The paper presents a detailed description of the test facility, results to evaluate the overall flow quality along side an aeroelastic model to predict the flutter velocity and critical interblade phase angles. Furthermore, chordwise pressure distributions, measured with traveling wave mode experimental tests, are presented. These measurements have been carried out for a wide ranges of interblade phase angles and have been compared to numerical results. Hotwire anemometry has been applied to examine the inlet flow for several Mach- and Reynolds numbers. The results show small turbulence intensities. The blade surface pressure Distribution and the flow field of the blade’s suction and pressure side has been obtained by oil flow visualization.