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The effect of flow curvature on the aerodynamic characteristics of an ogive-cylinder body

Published online by Cambridge University Press:  04 July 2016

D. I. T. P Llewelyn-Davies*
Affiliation:
Aerodynamics Department, College of Aeronautics, Cranfield Institute of Technology

Summary

The pressure distributions over a 6:1 fineness ratio ogive cylinder model have been obtained over a wide pitch range in the rectilinear flow provided by the CoA 8 ft x 6 ft low speed wind tunnel and the curvilinear motion provided by the CoA Whirling Arm facility. The pressure distributions were integrated first to obtain the local normal-force loading distribution along the body and then the overall normal-force and pitching moment and hence the centre of normal-force.

A comparison of the results showed that the main difference between the aerodynamic characteristics was a considerable positive increase in normal-force loading over the whole of the afterbody in curvilinear motion which varied little with the magnitude or sign of the pitch angle. Some smaller changes were also apparent in the forebody loading characteristics. These changes resulted in the body developing considerably more normal-force and nose-down pitching moment in curvilinear motion than in rectilinear flow with the resultant large rearward movement of the centre of normalforce.

It was found possible to estimate the main features of the loadings, but the theoretical methods available did not predict very well the variations in loading obtained experimentally at the extreme beginning and end of the parallel afterbody.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1989 

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References

1. Jones, R. The Distribution of Normal Pressures on a Prolate Spheroid. ARC R&M 1061, 1925.Google Scholar
2. Vandrey, F. A Method of Calculating the Pressure Distribution of a Body of Revolution Moving in a Circular Path Through a Perfect Incompressible Fluid. ARC R&M 3139, 1953.Google Scholar
3. Llewelyn-Davies, D. I. T. P. The Redesign of the College of Aeronautics Whirling Arm Facility. CoA Report 8702, March 1987.Google Scholar
4. Llewelyn-Davies, D. I. T. P. The Experimental Determination of the Subsonic Aerodynamic Characteristics of an Ogive- Cylinder Body Including a Comparison With Theoretical Estimates. CoA Report 8509, June 1985.Google Scholar
5. Llewelyn-Davies, D. I. T. P. The Determination of the Aerodynamic Characteristics of an Ogive-Cylinder Body in Subsonic, Curved, Incompressible Flow and an Assessment of the Effects of Flow Curvature. CoA Report 8713, December 1987.Google Scholar
6. Deo, H. S. Numerical techniques for predicting the aerodynamic characteristics of bodies. PhD Thesis, Cranfield Institute of Technology, 1986.Google Scholar
7. Petrie, J. A. H. Development of an efficient and versatile pansl method for aerodynamic problems. PhD Thesis, University of Leeds, 1979.Google Scholar
8. Isaacs, D. Store Carriage Loads at Subsonic Speeds. Part 1 — Prediction of the Load Distribution on Isolated Axisymmetrical Bodies. RAE Technical Report 88009, 1988.Google Scholar