Accession Number:

ADA355994

Title:

Nonlinear Modeling, Analysis, and Control of Turbomachinery Stall Flutter

Descriptive Note:

Final rept. 15 May 95-15 Aug 98

Corporate Author:

UNITED TECHNOLOGIES RESEARCH CENTER EAST HARTFORD CT

Personal Author(s):

Report Date:

1998-08-14

Pagination or Media Count:

70.0

Abstract:

The linear and nonlinear dynamic behavior of flexibly bladed turbomachines is presented. The analytical description is based on matching a two dimensional, incompressible flow field across a semi-actuator disk representation of a flexible rotor and a rigid stator. The aerodynamic loading on the rotor is derived using control volume formulations applied to discrete blade passages allowing consideration of finite interblade phase angles. Depending on operating parameters, the model exhibits behaviors classified as surge, rotating stall, and stall flutter which are qualitatively consistent with experimentally observed results. The formulation provides a tractable, nonlinear state space description of the dynamics responsible for surge, rotating stall, flutter, and their interaction. An analysis is performed for system parameters representative of a laboratory scale fan test facility. The behavior of the operability limiting instability modes is examined using time simulations, eigenvalue analysis and stability diagrams.

Subject Categories:

  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE