Wing Wake Measurements at High Reynolds Numbers by Means of Cryo PIV

Abstract

The wake flow of a high-lift aircraft model has been measured in the cryogenic transonic wind tunnel ETW using PIV. The wind tunnel, providing a 2.4 m wide and 2 m high test section, allows for measurements at the design point of the landing configuration, i.e. at a Reynolds number of 16.7 million and a Mach number of 0.2. To capture the wake flow along the complete wing span of the half model (half span width is ca. 1.5 m), a specific for the ETW developed cryo PIV system has been extended to use two Stereo-PIV setups in parallel. In the paper the employed cryo PIV setup is described with emphasis on the seeding technique using ice particles, the optical modules for an operation under cryogenic conditions and the automatic data acquisition system. Finally, the obtained results of the vortical wing wake flow are discussed for different angles of attack.