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Stability Theory for Cross-Hatching. Part II. An Experiment on Turbulent Boundary Layer over a Wavy Wall

Lees, L. and Kubota, T. and Sigal, A. (1972) Stability Theory for Cross-Hatching. Part II. An Experiment on Turbulent Boundary Layer over a Wavy Wall. Space and Missile Systems Organization (SAMSO), 72-34. California Institute of Technology , Pasadena, CA. http://resolver.caltech.edu/CaltechAUTHORS:20190117-174447349

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Abstract

An experimental investigation of turbulent boundary layer flow over wavy surfaces was conducted at low speed. Two models with the ratio of the amplitude to the wave length a/λ = 0.03 and wave lengths λ = 6" and 12" were tested in an open-circuit wind tunnel. The free stream velocity was 15.4 m/sec, giving Reynolds number Re = 2.54 X 10^4 per inch. Boundary-layer thickness varied from δ = 1.5" to δ = 4.1" by means of boundary-layer trips of various height, in order to change the ratio λ/δ. The fol- lowing measurements were taken: wall pressure distribution, average velocity and turbulence level, wall stress distribution, static and total pressures, and shear stress distribution across the layer. Wall pressure perturbation is much lower than predicted by uniform, inviscid theory and is slightly non-symmetric. Wall stress distribution has a peak with C_f/C_f_o = 1.2 upstream of the crest and a dip of C_f/C_f_o = 0.6 upstream of the trough. The turbulence intensities and shear stress distributions near the wall show oscillatory modulation superimposed on the reference flat plate pro- files. The amplitude of the oscillations decays exponentially toward the edge of the layer, so that in the outer part of the layer the turbulence quantities are practically independent of the longitudinal position.


Item Type:Report or Paper (Technical Report)
Alternate Title:Stability Theory for Cross-Hatching. Part II. An Experiment on Turbulent Boundary Layer over a Wavy Wall, Part II. An Experiment on Turbulent Boundary Layer over a Wavy Wall, An Experiment on Turbulent Boundary Layer over a Wavy Wall
Additional Information:Technical Report SAMSO TR 72-34, Vol. II. This report was prepared by the California Institute of Technology, Pasadena, California under USAF Contract F04701-68-C-0151, Project "Research on Fluid Mechanics of Striation Ablation." The work was administered under the direction of the Space and Missile Systems Organization, Air Force Systems Command. This report covers work performed between 1 September 1968 to 15 August 1971. Professors Lester Lees and Toshi Kubota were the Co-Principal Investigators, and Mr. Asher Sigal was a Graduate Research Assistant. The manuscript of this report was released by the authors in January 1972. This technical report has been reviewed and is approved.
Group:GALCIT
Funders:
Funding AgencyGrant Number
Air Force Systems CommandF04701-68-C-0151
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Other Numbering System NameOther Numbering System ID
SAMSO TR72-34, Vol. II
Record Number:CaltechAUTHORS:20190117-174447349
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20190117-174447349
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:92355
Collection:CaltechAUTHORS
Deposited By: Melissa Ray
Deposited On:18 Jan 2019 02:36
Last Modified:18 Jan 2019 02:36

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