首页>
外文会议>European Rotorcraft Forum
>28th EUROPEAN ROTORCRAFT FORUM Bristol, England - September 17-20, 2002 - Paper 42 The HART II Test in the LLF of the DNW - a Major Step towards Rotor Wake Understanding
【24h】
28th EUROPEAN ROTORCRAFT FORUM Bristol, England - September 17-20, 2002 - Paper 42 The HART II Test in the LLF of the DNW - a Major Step towards Rotor Wake Understanding
The HART program of 1994 led to deep insight into the effect of HHC on rotor behavior and its noise radiation. A key parameter to reduce rotor noise by HHC is the wake location relative to the blades. Wake data, however, had only been very scarse in HART, which was related to the flow measurement technique available at that time: 3C-LDV which provided conditionally averaged data by a relatively time consuming pointwise measurement in space. During the data analysis in the years after HART it was found that essentially comprehensive wake data are needed in order to get insight into wake development, vortex creation and aging, their motion in space and time and their re-development after an interaction with a rotor blade. Therefore, DLR, ONERA, NASA Langley, US Army AFDD and DNW again came together and created a follow-on program named HART II. The main focus was aiming on the rotor wake, which was investigated by the intensive use of a novel double stereo PIV system consisting of six laser oscillators and five digital cameras mounted on a large common traversing system. This provides instantaneous flow field data in both a large observation area and in a smaller close-up view to the vortex core. Additionally, rotor dynamics, aerodynamics, and noise radiation were subject of investigation to form a complete, consistent, and comprehensive database. Another "first time" was the blade position measurement technique SPR (Stereo Pattern Recognistion) which provides instantaneous optical measurement of the blade bending in flap, lead-lag and torsion. In this paper, the HART II test is described in detail, with all measurement techniques applied and with some results from each of them.
展开▼
