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Modeling of Atmospheric Turbulence as Disturbances for Control Design and Evaluation of High Speed Propulsion SystemsAtmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying integrated couplings between the propulsion and the vehicle structural dynamics for supersonic vehicles. Models based on the Kolmogorov spectrum have been previously utilized to model atmospheric turbulence. In this paper, a more accurate model is developed in its representative fractional order form, typical of atmospheric disturbances. This is accomplished by first scaling the Kolmogorov spectral to convert them into finite energy von Karman forms. Then a generalized formulation is developed in frequency domain for these scale models that approximates the fractional order with the products of first order transfer functions. Given the parameters describing the conditions of atmospheric disturbances and utilizing the derived formulations, the objective is to directly compute the transfer functions that describe these disturbances for acoustic velocity, temperature, pressure and density. Utilizing these computed transfer functions and choosing the disturbance frequencies of interest, time domain simulations of these representative atmospheric turbulences can be developed. These disturbance representations are then used to first develop considerations for disturbance rejection specifications for the design of the propulsion control system, and then to evaluate the closed-loop performance.
Document ID
20100012126
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Kopasakis, George
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2010
Subject Category
Aerodynamics
Report/Patent Number
E-17250
GT2010-22851
Meeting Information
Meeting: ASME TurboExpo Conference 2010: Power for Land, Sea and Air
Location: Glasgow
Country: United Kingdom
Start Date: June 14, 2010
End Date: June 18, 2010
Sponsors: American Society of Mechanical Engineers
Funding Number(s)
WBS: WBS 984754.02.07.03.20.02
Distribution Limits
Public
Copyright
Other

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