Aerodynamic coefficients of a symmetrical airfoil in an oscillating flow
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Authors
Chamberlain, George A.
Subjects
Oscillating flow
aerodynamic coefficients
symmetrical airfoil
aerodynamic coefficients
symmetrical airfoil
Advisors
Miller, James A.
Date of Issue
1990-09
Date
September 1990
Publisher
Monterey, California: Naval Postgraduate School
Language
Abstract
A symmetrical airfoil at fixed angle of attack from 0 to 35 degrees was placed in an air flow with controlled velocity oscillations at 10 Hz. The instantaneous pressure distribution and flow velocity were measured simultaneously. Pressure information was integrated numerically to determine instantaneous values for lift, drag and moment about the quarter chord. The results were plotted as three-dimensional surface plots in angle of attack, cycle time and performance coefficient axes, or with chordwise position, cycle time and pressure coefficient axes, as appropriate. The pressure distribution over the airfoil was shown to be primarily a function of freestream static pressure. Aerodynamic coefficients as a function of angle of attack and time exhibited seemingly random, erratic behavior, whereas the mean values of the same coefficients were similar in nature to those obtained in steady flow. The data indicate that the instantaneous performance of an airfoil in an oscillating flow is not merely a continuum of many quasi-steady states.
Type
Thesis
Description
Series/Report No
Department
Naval Postgraduate School (U.S.)
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funding
Format
vi, 95 p. : ill. ; 28 cm.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.