Accession Number:

ADA059437

Title:

Unsteady Transonic Diffuser Flows in a Two-Dimensional Diffuser.

Descriptive Note:

Annual rept. 1 Apr 77-31 Mar 78,

Corporate Author:

MCDONNELL DOUGLAS RESEARCH LABS ST LOUIS MO

Personal Author(s):

Report Date:

1978-05-01

Pagination or Media Count:

30.0

Abstract:

The present study is part of a continuing investigation of unsteady, transonic diffuser flows, with application to dynamic distortion in the inlets of fighter aircraft and airbreathing missile propulsion systems. The investigation is focused on a simple, two-dimensional diffuser configuration displaying a weak shock shortly downstream of the throat Figure 1. Flows in this model were found to display self-excited oscillations involving the shock and the entire subsonic flow behind it. The shock displacement amplitudes are comparable to the throat height and occur at frequencies characterized by the flow speed and the length of the divergent diffuser section. The time-mean and fluctuating properties of this flow and the dependence of these properties on shock strength have been documented.

Subject Categories:

  • Fluid Mechanics
  • Air Breathing Engines (Unconventional)

Distribution Statement:

APPROVED FOR PUBLIC RELEASE