A Numerical Comparison of Symmetric and Asymmetric Supersonic Wind Tunnels

A Numerical Comparison of Symmetric and Asymmetric Supersonic Wind Tunnels
Author: Kylen D. Clark
Publisher:
Total Pages: 138
Release: 2015
Genre:
ISBN:

Supersonic wind tunnels are a vital aspect to the aerospace industry. Both the design and testing processes of different aerospace components often include and depend upon utilization of supersonic test facilities. Engine inlets, wing shapes, and body aerodynamics, to name a few, are aspects of aircraft that are frequently subjected to supersonic conditions in use, and thus often require supersonic wind tunnel testing. There is a need for reliable and repeatable supersonic test facilities in order to help create these vital components. The option of building and using asymmetric supersonic converging-diverging nozzles may be appealing due in part to lower construction costs. There is a need, however, to investigate the differences, if any, in the flow characteristics and performance of asymmetric type supersonic wind tunnels in comparison to symmetric due to the fact that asymmetric configurations of CD nozzle are not as common. A computational fluid dynamics (CFD) study has been conducted on an existing University of Michigan (UM) asymmetric supersonic wind tunnel geometry in order to study the effects of asymmetry on supersonic wind tunnel performance. Simulations were made on both the existing asymmetrical tunnel geometry and two axisymmetric reflections (of differing aspect ratio) of that original tunnel geometry. The Reynolds Averaged Navier Stokes equations are solved via NASA's OVERFLOW code to model flow through these configurations. In this way, information has been gleaned on the effects of asymmetry on supersonic wind tunnel performance. Shock boundary layer interactions are paid particular attention since the test section integrity is greatly dependent upon these interactions. Boundary layer and overall flow characteristics are studied. The RANS study presented in this document shows that the UM asymmetric wind tunnel/nozzle configuration is not as well suited to producing uniform test section flow as that of a symmetric configuration, specifically one that has been scaled to have equal aspect ratio. Comparisons of numerous parameters, such as flow angles, pressure (both static and stagnation), entropy, boundary layers and displacement thickness, vorticity, etc. paint a picture that shows the symmetric equal aspect ratio configuration to be decidedly better at producing desirable test section flow. It has been shown that virtually all parameters of interest are both more consistent and have lower deviation from ideal conditions for the symmetric equal area configuration.

A Comparison of Transition Reynolds Numbers from 12-in. and 40-in. Supersonic Tunnels

A Comparison of Transition Reynolds Numbers from 12-in. and 40-in. Supersonic Tunnels
Author: C. J. Schueler
Publisher:
Total Pages: 42
Release: 1963
Genre: Aerodynamics, Supersonic
ISBN:

Transition Reynolds number measurements on a hollow cylinder in the von Karman Gas Dynamics Facility's 12-inch and 40-inch supersonic tunnels show that the highest transition Reynolds numbers were obtained in the 40-inch tunnel, although the variations with unit Reynolds number were the same at Mach numbers 3 to 5. The influence of nose bluntness in the 40-inch tunnel corresponds closely with the results obtained in the 12-inch tunnel.

NASA SP.

NASA SP.
Author:
Publisher:
Total Pages: 654
Release: 1992
Genre: Aeronautics
ISBN:

New Results in Numerical and Experimental Fluid Mechanics II

New Results in Numerical and Experimental Fluid Mechanics II
Author: Wolfgang Nitsche
Publisher: Springer Science & Business Media
Total Pages: 550
Release: 2013-11-11
Genre: Mathematics
ISBN: 3663109011

This volume contains the papers of the 11th Symposium of the AG STAB (German Aerospace Aerodynamics Association). In this association those scientists and engineers from universities, research-establishments and industry are involved, who are doing research and project work in numerical and experimental fluid mechanics and aerodynamics for aerospace and other applications. Many of the contributions are giving results from the "Luftfahrtforschungsprogramm der Bundesregierung (German Aeronautical Research Programme). Some of the papers report on work sponsored by the Deutsche Forschungsgemeinschaft, DFG, which also was presented at the symposium. The volume gives a broad overview over the ongoing work in this field in Germany.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports
Author:
Publisher:
Total Pages: 538
Release: 1995
Genre: Aeronautics
ISBN:

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.