Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 3 Parameters Estimated from Flight Data Part 3 Parameters Estimated from Flight Data written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-05 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: A nonlinear least squares algorithm for aircraft parameter estimation from flight data was developed. The postulated model for the analysis represented longitudinal, short period motion of an aircraft. The corresponding aerodynamic model equations included indicial functions (unsteady terms) and conventional stability and control derivatives. The indicial functions were modeled as simple exponential functions. The estimation procedure was applied in five examples. Four of the examples used simulated and flight data from small amplitude maneuvers to the F-18 HARV and X-31A aircraft. In the fifth example a rapid, large amplitude maneuver of the X-31 drop model was analyzed. From data analysis of small amplitude maneuvers ft was found that the model with conventional stability and control derivatives was adequate. Also, parameter estimation from a rapid, large amplitude maneuver did not reveal any noticeable presence of unsteady aerodynamics. Klein, Vladislav and Noderer, Keith D. Langley Research Center RTOP 505-64-52-01...
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 3 Parameters Estimated from Flight Data written by and published by . This book was released on 1996 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 2 Parameters Estimated from Wind Tunnel Data written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-28 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamic equations with unsteady effects were formulated for an aircraft in one-degree-of-freedom, small-amplitude, harmonic motion. These equations were used as a model for aerodynamic parameter estimation from wind tunnel oscillatory data. The estimation algorithm was based on nonlinear least squares and was applied in three examples to the oscillatory data in pitch and roll of 70 deg triangular wing and an X-31 model, and in-sideslip oscillatory data of the High Incidence Research Model 2 (HIRM 2). All three examples indicated that a model using a simple indicial function can explain unsteady effects observed in measured data. The accuracy of the estimated parameters and model verification were strongly influenced by the number of data points with respect to the number of unknown parameters. Klein, Vladislav and Noderer, Keith D. Langley Research Center RTOP 505-64-52-01...
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics written by Vladislav Klein and published by . This book was released on 1994 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamic equations with unsteady effects were formulated for an aircraft in one-degree-of-freedom, small-amplitude, harmonic motion. These equations were used as a model for aerodynamic parameter estimation from wind tunnel oscillatory data. The estimation algorithm was based on nonlinear least squares and was applied in three examples to the oscillatory data in pitch and roll of 70 degree triangular wing and an X-31 model, and in-sideslip oscillatory data of the High Incidence Research Model 2 (HIRM 2). All three examples indicated that a model using a simple indicial function can explain unsteady effects observed in measured data. The accuracy of the estimated parameters and model verification were strongly influenced by the number of data points with respect to the number of unknown parameters.
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 1 Postulated Models written by and published by . This book was released on 1994 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 1 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-05 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A short theoretical study of aircraft aerodynamic model equations with unsteady effects is presented. The aerodynamic forces and moments are expressed in terms of indicial functions or internal state variables. The first representation leads to aircraft integro-differential equations of motion; the second preserves the state-space form of the model equations. The formulations of unsteady aerodynamics is applied in two examples. The first example deals with a one-degree-of-freedom harmonic motion about one of the aircraft body axes. In the second example, the equations for longitudinal short-period motion are developed. In these examples, only linear aerodynamic terms are considered. The indicial functions are postulated as simple exponentials and the internal state variables are governed by linear, time-invariant, first-order differential equations. It is shown that both approaches to the modeling of unsteady aerodynamics lead to identical models. Klein, Vladislav and Noderer, Keith D. Langley Research Center RTOP 505-64-52-01...
Download or read book Estimation of Aircraft Nonlinear Unsteady Parameters From Wind Tunnel Data written by Vladislav Klein and published by . This book was released on 1998 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 2 Parameters Estimated from Wind Tunnel Data written by and published by . This book was released on 1995 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics written by Vladislav Klein and published by . This book was released on 1994 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling of Unsteady Aerodynamic Characteristics for Aircraft Dynamics Applications at High Incidence Flight written by Nikolay Abramov and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A traditional representation of aerodynamic characteristics based on the concept of aerodynamic derivatives fails to be accurate at high angles of attack due to significant dynamic effects generated from separated and vortical flow. As the possibility of performing controlled flight at high angles of attack has already become a common requirement for modern combat aircraft, the problem of an adequate model for aerodynamic loads at high incidences is the issue of the day. This thesis presents a phenomenological approach to modelling of unsteady aerodynamic characteristics at high angles of attack. In this approach aerodynamic characteristics are considered as a combination of two components having different characteristic time scales which describe the contribution to the total aerodynamic load from the different flow structures. It is assumed that all dynamic properties of the flow are amassed in the' slow' component. To describe its behaviour specially designed nonlinear differential equations are used. Depending on the parameters, this model can reproduce both 'weak' and 'strong' nonlinear effects including static hysteresis. A special identification technique has been developed for the estimation of the model parameters using dynamic wind tunnel test data.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1996 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Aircraft Unsteady Aerodynamic Characteristics written by Vladislav Klein and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Aerospace Sciences Meeting and Exhibit 42nd written by and published by . This book was released on 2004 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1971 with total page 1388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications Cumulative Index written by United States. Superintendent of Documents and published by . This book was released on 1976 with total page 1408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
