Accession Number:

AD0700926

Title:

FLOW SEPARATION IN TIME VARYING FLOW.

Descriptive Note:

Technical rept.,

Corporate Author:

COLORADO STATE UNIV FORT COLLINS FLUID DYNAMICS AND DIFFUSION LAB

Personal Author(s):

• Chou,Fang-Kuo
• Sandborn,V. A.

Report Date:

1969-12-01

Pagination or Media Count:

64.0

Abstract:

An exact solution of time varying pipe flow with a fluctuating velocity superimposed on the mean flow is analyzed. The velocity profiles, together with the profile parameters at separation, are computed from a computer program. The results are compared with the model for relaxed steady and unrelaxed unsteady separation criteria proposed by V. A. Sandborn and S. J. Kline. For very low frequencies, the correlation curves appear to have a reasonable agreement with the proposed relaxed separation criterion. For high frequencies, the correlation curves were found to fall approximately on the unrelaxed separation criterion. This result demonstrates further that adjustment time is an important factor for separation to be relaxed or unrelaxed, a new concept proposed by Sandborn. In addition, J. T. Stuarts solution for the flow along an infinite flat plate with normal suction and periodic external velocity is further analyzed. The results again prove to agree with the proposed new concept. Author

Descriptors:

• (*FLOW SEPARATION
• BOUNDARY LAYER)
• SHEAR STRESSES
• RELAXATION TIME
• PIPES
• VELOCITY
• CORRELATION TECHNIQUES
• FLAT PLATE MODELS
• PERIODIC VARIATIONS

Subject Categories:

• Aerodynamics
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE