M. Vella, B. Augere, A. Dolfi, D. Goular, D. Fleury

The objective of Onera study in the AIM project "Advanced In-flight Measurement Techniques" is to assess the capability of on board lidar technique to investigate in-flight tip vortices behaviour. This paper presents the design of a 1.5ìm lidar sensor dedicated to tip vortex detection and tests on ground during a trials campaign on DLR helicopter in hover flight. The relevant information resulting from these trials is tip vortex velocity field but also vortex evolution according to time. The technical challenge here is to characterize a very small phenomenon at short range: vortex core radius with respect to age varies from typically 10 to 30 mm. Study result shows that lidar technique is promising for onboard measurement in real flight conditions. The velocity measurement is direct and absolute (not calibration needed) and its accuracy can be up to 0.25 m/s and commonly 1m.s-1. However, seeding is necessary to realize a compact and reliable lidar system with components "off the shelf": flight measurements within clouds could be a very good solution for efficient and powerful vortex lidar.

35th European Rotorcraft Forum 2009,

Conference Paper

englisch

21,0 x 29,7 cm, 5 Seiten

DGLR-Bericht, 2009, 2009-03, 35th European Rotorcraft Forum 2009 - Conference Proceedings; S.1-5; 2009; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

detection, rotors, vortices, lidar

Bestellbar

2009