
Accession Number : ADA118591
Title : Unsteady Boundary Layer Due to an Oscillating Free Stream vs. an Oscillating Model.
Descriptive Note : Final rept. 15 May 8014 May 81,
Corporate Author : SOUTH CAROLINA UNIV COLUMBIA COLL OF ENGINEERING
Personal Author(s) : Wilson,Dennis E
PDF Url : ADA118591
Report Date : 25 Jun 1982
Pagination or Media Count : 59
Abstract : The objective of this investigation is to calculate the unsteady boundary layer induced on a thin airfoil by two distinct mechanisms. First, a uniform upstream flow approaches an airfoil which is undergoing a periodic transverse oscillation of specified frequency and amplitude with respect to the wind tunnel. And secondly, a uniform upstream flow approaches the same airfoil which is fixed with respect to the wind tunnel but is now subjected to transverse oscillating flow. The transverse flow is produced at the walls of the wind tunnel test section and will contain a spatial distribution at the test section centerline. The method employed in this analysis uses the classical potential flow/boundary layer interaction. The mathematical model assumes a laminar incompressible flow over a twodimensional thin airfoil. In addition, the amplitude of the transverse oscillation is assumed to be small with respect to the chord of the airfoil. This restriction is also equivalent to small transverse velocities relative to the upstream flow, if the frequencies are moderate. This assumption produces a set of linear disturbance equations for the unsteady flow. No other restrictions are placed upon the spatial distribution of the transverse flow, although results are presented only for cosine distribution which represents the worst possible case. (Author)
Descriptors : *Boundary layer flow, *Unsteady flow, Free stream, Oscillation, Airfoils, Mathematical models
Subject Categories : Numerical Mathematics
Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE