Measurements of a rotor flow in ground effect and visualization of the brown-out phenomenon

Nathan, N. and Green, R. (2008) Measurements of a rotor flow in ground effect and visualization of the brown-out phenomenon. In: 64th American Helicopter Society Annual Forum, Montreal, Canada, 29 Apr – 1 May 2008,

Abstract

Quantitative and qualitative results of a series of experiments conducted on a rotor in ground effect at low forward speeds are presented. The velocity over a wide area of the ground effect wake was measured using Particle Image Velocimetry (PIV), and the evolution of the flow is described as the forward speed increases. Helicopter brown-out was simulated through a series of flow visualisation experiments. The technique involved sprinkling a fine powder on the ground below and ahead of the rotor. This helps to validate the experimental simulation of the brown-out phenomenon. Larger dust clouds were observed at lower advance ratio, and the dust cloud penetrated into the areas of the flow including those where vorticity levels were of low or negligible magnitude.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Green, Dr Richard
• Authors: Nathan, N., and Green, R.
• Subjects: T Technology > TL Motor vehicles. Aeronautics. Astronautics
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Research Group: Low Speed Aerodynamics
• Copyright Holders: Copyright © 2008 American Helicopter Society International, Inc.
• First Published: First published in proceedings of the 64th American Helicopter Society Annual Forum
• Publisher Policy: Reproduced with permission of the Vertical Flight Society