This item is under embargo and not available online per the author's request. For access information, please visit http://libanswers.wustl.edu/faq/5640.

Date of Award

Winter 12-15-2018

Author's School

School of Engineering & Applied Science

Author's Department

Mechanical Engineering & Materials Science

Degree Name

Doctor of Philosophy (PhD)

Degree Type

Dissertation

Abstract

Dynamic stall is a complex aerodynamic phenomenon occurring in helicopter rotors, limiting the flight envelope and causing control linkage damage and instabilities. The Peters-Modarres semi-empirical dynamic stall model is extended to simulate pitching moment and drag in unsteady freestream and yawed flow, including the effects of secondary stall. The aerodynamics are implemented as a state-space model, suitable for time-marching or aeroelastic analyses. With small modifications to the original stall model, secondary stall effects and unsteady freestream can be simulated without adding additional states. An optimization routine determines sets of parameters that minimize the error between the modeled solution and experimental data. The stall model is validated against five wind tunnel tests with a range of aerodynamic conditions. The results show good qualitative correlation with each test case, improving on the pitching moment and drag results of previously found by Ahaus.

Language

English (en)

Chair

David A. Peters

Comments

Permanent URL: https://doi.org/10.7936/9dva-7q82

Available for download on Friday, January 24, 2020

Share

COinS