Degree Type

Dissertation

Date of Award

1987

Degree Name

Doctor of Philosophy

Department

Aerospace Engineering

Abstract

Low-contraction ratio wind tunnel inlets have been shown to generate nonuniform velocity fields in the location where it is necessary to place anti-turbulence screens. The pressure drop experienced by the flow passing through the screens is proportional to the local dynamic pressure and can, therefore, result in a nonuniform test-section velocity distribution. The interaction of screens and two-dimensional inlet flow was examined in this study both theoretically and experimentally. The results indicate that the addition of more screens does not improve the test-section velocity distribution except for a very limited range of inlet geometries. In addition, the turning of the flow by the screens was found to be the most important factor influencing the inlet flow distribution and that the turning action of the screens must be included in any analysis of this type of flow. The use of a set of turning vanes (cascade) upstream of the screens was found to be effective in modifying the inlet flow distribution so as to generate a uniform test-section velocity distribution. A successful application of the inlet cascade to the 80- by 120-Foot Wind Tunnel at NASA Ames Research Center is also presented.

DOI

https://doi.org/10.31274/rtd-180813-8642

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

James Carl Ross

Language

en

Proquest ID

AAI8716812

File Format

application/pdf

File Size

131 pages

Share

COinS