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Loads and Pressures Due to Underexpanded Jets Impinging on Wedges*

Published online by Cambridge University Press:  07 June 2016

B.L. Hunt
B.L. Hunt*
Affiliation:
Northrop Corporation
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Summary

Loads have been measured on wedges placed symmetrically in supersonic jets of air. The jets were created by a nozzle with a radially divergent exit section having a lip Mach number of 2.2. The underexpansion ratio was varied from 1 to 2.2 and the distance between the nozzle exit section and the wedge apex was varied from 0 to 2 nozzle exit diameters. All wedges had a base width equal to the nozzle exit diameter: their total included apex angles covered the range 30° to 180°. Pressures were measured on the front faces and the bases for three of the wedges, hence enabling individual contributions to the overall force to be evaluated. Overall loads were measured by means of strain-gauged supports for all six wedges. It was found that the overall load coefficient is only weakly dependent on underexpansion ratio and wedge location but depends strongly on wedge angle. The maximum load coefficient recorded corresponded to 73% of the jet momentum. The base pressures contribute up to 59% of the overall load on a 45° wedge but rather less for larger wedge angles.

Type
Research Article
Information
Aeronautical Quarterly , Volume 34 , Issue 2 , May 1983 , pp. 76 - 98
Copyright
Copyright © Royal Aeronautical Society. 1983

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Footnotes

*

This work was carried out while the author was a member of the Department of Aeronautical Engineering of the University of Bristol

References

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