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Modelling of static aerodynamics of helicopter underslung loads

Published online by Cambridge University Press:  27 January 2016

D. I. Greenwell
D. I. Greenwell*
Affiliation:
Centre for Aeronautics, City University, London, UK
*
d.greenwell@city.ac.uk
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Abstract

The complex aerodynamics of rectangular underslung helicopter loads can lead to severe stability problems, but are difficult to represent in flight dynamics models. Current models for box aerodynamics are highly unsatisfactory, being entirely empirical and requiring large amounts of experimental data to generate. This paper presents a new modelling approach, which takes account of the bluff-body nature of the flow, where loads are dominated by normal pressure forces. Existing experimental data is recast in body-axes form, with α and β replaced by velocity components perpendicular and parallel to the box faces. Force and moment data for a wide range of boxes then collapse onto a set of simple generic characteristics, with features that can be related directly to the underlying flow physics. Modelling of container aerodynamics is greatly simplified, and allowance for effects of turbulence, Reynolds Number, wind tunnel interference and geometry modifications becomes possible.

Type
Research Article
Information
The Aeronautical Journal , Volume 115 , Issue 1166 , April 2011 , pp. 201 - 219
Copyright
Copyright © Royal Aeronautical Society 2011 

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