Accession Number:

AD0432065

Title:

UNSTEADY BOUNDARY LAYER THEORY,

Descriptive Note:

Corporate Author:

FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s):

Report Date:

1964-01-13

Pagination or Media Count:

44.0

Abstract:

A general theory is developed for an unsteady boundary layer on cylindrical bodies of arbitrary cross section and on solids of revolution. A generalization of the basic integral methods of calculating a stationary boundary layer for the case of an arbitrary unsteady boundary layer is given. A new integral method of calculating the boundary layer is developed which more fully takes into account the features of unsteady processes. An exact solution of the equations of an unsteady boundary layer was found for a flat plate. The relationships between the characteristics of an unsteady boundary layer and the relative velocity in the case of unsteady fluid motion is obtained. A positive relative acceleration fosters separationless flow around the wing, while a negative relative acceleration promotes flow separation. The variable value of the relative acceleration leads to variable separation of the vortices from the wing surface. On the basis of the general relationships obtained in this study the effect of unsteady motion of an aircraft on its aerodynamic characteristics is determined qualitatively. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE