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A numerical study of the effects of wind tunnel wall proximity on an airfoil modelA procedure was developed for modeling wind tunnel flows using computational fluid dynamics. Using this method, a numerical study was undertaken to explore the effects of solid wind tunnel wall proximity and Reynolds number on a two-dimensional airfoil model at low speed. Wind tunnel walls are located at varying wind tunnel height to airfoil chord ratios and the results are compared with freestream flow in the absence of wind tunnel walls. Discrepancies between the constrained and unconstrained flows can be attributed to the presence of the walls. Results are for a Mach Number of 0.25 at angles of attack through stall. A typical wind tunnel Reynolds number of 1,200,000 and full-scale flight Reynolds number of 6,000,000 were investigated. At this low Mach number, wind tunnel wall corrections to Mach number and angle of attack are supported. Reynolds number effects are seen to be a consideration in wind tunnel testing and wall interference correction methods. An unstructured grid Navier-Stokes code is used with a Baldwin-Lomax turbulence model. The numerical method is described since unstructured flow solvers present several difficulties and fundamental differences from structured grid codes, especially in the area of turbulence modeling and grid generation.
Document ID
19910001621
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Potsdam, Mark
(Stanford Univ. CA, United States)
Roberts, Leonard
(Stanford Univ. CA, United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1990
Subject Category
Aerodynamics
Report/Patent Number
JIAA-TR-99
NAS 1.26:187322
NASA-CR-187322
Accession Number
91N10934
Funding Number(s)
CONTRACT_GRANT: NCC2-55
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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