Accession Number:

ADA199211

Title:

Advances in the Numerical Analysis of Linearized Unsteady Cascade Flows

Descriptive Note:

Interim technical rept. Feb 1985-May 1988

Corporate Author:

UNITED TECHNOLOGIES RESEARCH CENTER EAST HARTFORD CT

Report Date:

1988-08-01

Pagination or Media Count:

75.0

Abstract:

This report describes two new developments in the numerical analysis of linearized unsteady cascade flows, which have been motivated by the need for an accurate analytical procedure for predicting the onset of flutter in highly loaded compressor cascades. Numerical solutions have been determined using a two step procedure which first determined on a rectilinear-type cascade mesh to determine the unsteady flow over an extended blade-passage solution domain and then used polar-type local mesh to resolve the unsteady flow in high-gradient regions. In the present effort a composite solution procedure has been developed in which the cascade and local mesh equations are solved simultaneously. This allows the detail features of the flow within the local mesh region to impact the unsteady solution over the entire domain. In addition, a new shock- conforming local mesh has been introduced to permit a more accurate modeling of unsteady shock phenomena. Numerical results are presented to demonstrate the impact of the new composite solution procedure and the new local mesh on unsteady flow predictions. Results are also presented to illustrate the global unsteady aerodynamic response behavior of a compressor-type cascade operating at high subsonic inlet Mach numbers and at high mean incidences.

Subject Categories:

  • Hydraulic and Pneumatic Equipment
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE