Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-21T09:41:39.340Z Has data issue: false hasContentIssue false

Design parameters and performance of two-dimensional, asymmetric, ‘sliding block’, variable Mach number, supersonic nozzles

Published online by Cambridge University Press:  04 July 2016

H. Winarto
Affiliation:
Department of Mechanical Engineering, University of Queensland, Australia
R. J. Stalker
Affiliation:
Department of Mechanical Engineering, University of Queensland, Australia

Extract

The ‘sliding block’ asymmetric nozzle, which is mechanically simple and robust, is ideal for a small, variable Mach number supersonic wind tunnel installation, due the fact that it is affordable and relatively easy to manufacture. Until now there has been no rational procedure for selecting the correct nozzle profiles to satisfy certain predetermined nozzle performance criteria, ie, a range of operating Mach numbers and an acceptable test section flow non-uniformity over the given range. The present paper considers the minimum requirements which are sufficient and necessary to design an asymmetric nozzle and shows that these can be met by nozzles defined in terms of a shape parameter, an angular parameter and a length parameter. The lower end of the range of operating Mach numbers is determined by the choice of the overall flow turning angle. For a family of nozzles defined by a particular shape parameter, an heuristic analysis indicates how the test section flow non-uniformity must vary as a function of a variable which is a particular grouping of the angular and length parameters, and the range of operating Mach numbers. The dependence of the nozzle performance on the parameters is investigated numerically, assuming inviscid flow and utilising the method of characteristics. The result shows that the best nozzle shape is where the flow is expanded very rapidly immediately downstream of the throat. For a particular family of nozzles, the numerical analysis shows the complex relationship between nozzle performance and the angular and length parameters, which is best described in a graphical representation. As a result, the task of selecting correct profiles for sliding block nozzles is reduced to simply selecting the appropriate values of nozzle parameters from the curves supplied.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1984 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

*

Now at BPP Technologi, Jakarta, Indonesia.

References

1. Rosen, J. The Design and Calibration of a variable Mach number nozzle. Journal Aeronautical Sciences, July 1955, 22, 484.Google Scholar
2. Jackson, C. M., Corlett, W. A. and Monta, W. J. Description and Calibration of the Langley Unitary Plan Wind Tunnel. NASA Technical Paper 1905, November 1981.Google Scholar
3. Liepman, H. P. An analytic Method for the Design of Two-Dimensional Asymmetric Nozzles. Journal Aeronautical Sciences, October 1955, 22, 701.Google Scholar
4. Oswatitsch, L. Gas Dynamics. Academic Press, New York, 1956, 408.Google Scholar
5. Liepman, H. W. and Roshko, A. Elements of Gas Dynamics. John Wiley and Sons, New York, 1956, 284.Google Scholar
6. Shapiro, A. H. The Dynamics and Thermodynamics of Compressible Fluid Flow. 1 and 2. The Ronald Press, Co, New York, 1958, 462.Google Scholar