Results Obtained in Tests Using Three Simple Methods for Converting Frequency-Domain Aerodynamics to the Time Domain.

Abstract

The approach used here has been to obtain time-domain representations that are sums of exponentials. This, in turn, requires frequency domain approximations that are rational functions of the Laplace transform variables. Three simple methods for obtaining rational function approximations for frequency domain unsteady aerodynamic data have been tested. A number of satisfactory approximations were achieved, but many approximations were poor. In this report, the use of equally spaced poles proved to be the most successful. Keywords: Unsteady flow; Aerodynamics; Control theory; Active control; Least squares method; and Australia.

Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1984
Accession Number
ADA168765

Entities

People

  • Betty Emslie
  • T. G. Ryall

Tags

DTIC Thesaurus Topics

  • Aerodynamics
  • Australia
  • Control Theory
  • Flow
  • Frequency
  • Frequency Domain
  • Least Squares Method
  • Rational Functions
  • Time Domain
  • Unsteady Flow

Readers

  • Aerodynamics/Aeronautics.
  • Approximation Theory.

Technology Areas

  • Space