Flow visualisation of the helicopter brown-out phenomenon

Nathan, N.D. and Green, R.B. (2009) Flow visualisation of the helicopter brown-out phenomenon. Aeronautical Journal, 113(1145), pp. 467-478.

Abstract

Quantitative and qualitative results of a series of experiments conducted oil 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, and the evolution of the flow is described as the forward speed increases. The formation of a dust cloud leading to so-called helicopter brown-out was simulated through a series of flow visualisation experiments. The technique involved sprinkling a fine dust on the ground below and ahead of the rotor. Larger dust clouds were observed at lower forward speed, and the dust cloud penetrated into the areas of the flow including those where vorticity levels were of low magnitude and occasional velocity fluctuations from the mean were large.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Green, Dr Richard
• Authors: Nathan, N.D., and Green, R.B.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Aeronautical Journal
• ISSN: 0001-9240