Download or read book Atmospheric Turbulence Modeling for Aero Vehicles Fractional Order Fits written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2019-01-13 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying coupling 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 and then by deriving an explicit fractional circuit-filter type analog for this model. This circuit model is utilized to develop a generalized formulation in frequency domain to approximate the fractional order with the products of first order transfer functions, which enables accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest. Kopasakis, George Glenn Research Center NASA/TM-2010-216961, E-17566
Download or read book Atmospheric Turbulence Modeling for Aero Vehicles written by National Aeronautics and Space Administration (NASA) and published by . This book was released on 2010-11-01 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying coupling 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 and then by deriving an explicit fractional circuit-filter type analog for this model. This circuit model is utilized to develop a generalized formulation in frequency domain to approximate the fractional order with the products of first order transfer functions, which enables accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.
Download or read book Atmospheric Turbulence Modeling for Aero Vehicles written by George Kopasakis and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Turbulence Modeling for Aero Vehicles written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-07 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying coupling 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 and then by deriving an explicit fractional circuit-filter type analog for this model. This circuit model is utilized to develop a generalized formulation in frequency domain to approximate the fractional order with the products of first order transfer functions, which enables accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.
Download or read book Atmospheric Turbulence Modeling for Aero Vehicles written by George Kopasakis and published by . This book was released on 2015 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Turbulence written by Hans A. Panofsky and published by Wiley-Interscience. This book was released on 1984-02-03 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: New York : Wiley, c1984.
Download or read book Unsteady Aerodynamic Modeling of Aircraft Response to Atmospheric Turbulence written by Jilu Li and published by . This book was released on 2003 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Turbulence Simulation Techniques with Application to Flight Analysis written by Show-Tien Wang and published by . This book was released on 1980 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Statistical modeling of atmospheric turbulence is discussed. The statistical properties of atmospheric turbulence, in particular the probability distribution, the spectra, and the coherence are reviewed. Different atmospheric turbulence simulation models are investigated, and appropriate statistical analyses are carried out to verify their validity. The models for simulation are incorporated into a computer model of aircraft flight dynamics. Statistical results of computer simulated landings for an aircraft having characteristics of a DC-8 are reported for the different turbulence simulation techniques. The significance of various degrees of sophistication in the turbulence simulation techniques on the landing performance of the aircraft is discussed.
Download or read book A Non gaussian Model of Continuous Atmospheric Turbulence for Use in Aircraft Design written by Paul M. Reeves and published by . This book was released on 1976 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Real time Atmospheric Turbulence Model for Aircraft Flight Simulators written by Cameron Philip Ninham and published by . This book was released on 2005 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Implementation and Testing of Turbulence Models for the F18 Harv Simulation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-18 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents three methods of implementing the Dryden power spectral density model for atmospheric turbulence. Included are the equations which define the three methods and computer source code written in Advanced Continuous Simulation Language to implement the equations. Time-history plots and sample statistics of simulated turbulence results from executing the code in a test program are also presented. Power spectral densities were computed for sample sequences of turbulence and are plotted for comparison with the Dryden spectra. The three model implementations were installed in a nonlinear six-degree-of-freedom simulation of the High Alpha Research Vehicle airplane. Aircraft simulation responses to turbulence generated with the three implementations are presented as plots. Yeager, Jessie C. Langley Research Center TURBULENCE MODELS; ATMOSPHERIC TURBULENCE; ATMOSPHERIC MODELS; FLIGHT CHARACTERISTICS; AIRCRAFT PERFORMANCE; RESEARCH VEHICLES; DEGREES OF FREEDOM; SPECTRAL THEORY; COMPUTER PROGRAMS; NONLINEARITY...
Download or read book A Real time Atmospheric Turbulence Model for Aircraft Flight Simulators written by Cameron P. Ninham and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Nongaussian Atmospheric Turbulence for Prediction of Aircraft Response Statistics written by William D. Mark and published by . This book was released on 1977 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aviation Turbulence written by Robert Sharman and published by Springer. This book was released on 2016-06-27 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anyone who has experienced turbulence in flight knows that it is usually not pleasant, and may wonder why this is so difficult to avoid. The book includes papers by various aviation turbulence researchers and provides background into the nature and causes of atmospheric turbulence that affect aircraft motion, and contains surveys of the latest techniques for remote and in situ sensing and forecasting of the turbulence phenomenon. It provides updates on the state-of-the-art research since earlier studies in the 1960s on clear-air turbulence, explains recent new understanding into turbulence generation by thunderstorms, and summarizes future challenges in turbulence prediction and avoidance.
Download or read book Atmospheric Turbulence Meteorological Modeling and Aerodynamics written by Peter R. Lang and published by . This book was released on 2010 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric turbulence and unsteady aerodynamics in aircraft simulation written by and published by . This book was released on 1985 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling U 2 Flight Through Clear Air Turbulence written by and published by . This book was released on 2007 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: A dynamic three degrees-of-freedom simulation of the U-2 aircraft was developed in support of future Clear Air Turbulence (CAT) forecasting. Aerodynamic coefficients and the autopilot specification were obtained from the Lockheed Martin Aeronautics Company. The simulation used longitudinal aircraft equaitons of motion to model the aircraft's flight through CAT. The dynamics were modified to include non-steady relatilve wind conditions. Atmospheric inputs were created using wave models and other numerical simulations of CAT conditions. The results were compared to traditional turbulence sensitivity predictors, which appeared to under-predict the actual aircraft loads for some CAT conditions.
