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Book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 1

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...

Book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 3 Parameters Estimated from Flight Data Part 3 Parameters Estimated from Flight Data

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...

Book Computational Aerodynamic Modeling of Aerospace Vehicles

Download or read book Computational Aerodynamic Modeling of Aerospace Vehicles written by Mehdi Ghoreyshi and published by MDPI. This book was released on 2019-03-08 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, the use of computational fluid dynamics (CFD) solutions is considered as the state-of-the-art in the modeling of unsteady nonlinear flow physics and offers an early and improved understanding of air vehicle aerodynamics and stability and control characteristics. This Special Issue covers recent computational efforts on simulation of aerospace vehicles including fighter aircraft, rotorcraft, propeller driven vehicles, unmanned vehicle, projectiles, and air drop configurations. The complex flow physics of these configurations pose significant challenges in CFD modeling. Some of these challenges include prediction of vortical flows and shock waves, rapid maneuvering aircraft with fast moving control surfaces, and interactions between propellers and wing, fluid and structure, boundary layer and shock waves. Additional topic of interest in this Special Issue is the use of CFD tools in aircraft design and flight mechanics. The problem with these applications is the computational cost involved, particularly if this is viewed as a brute-force calculation of vehicle’s aerodynamics through its flight envelope. To make progress in routinely using of CFD in aircraft design, methods based on sampling, model updating and system identification should be considered.

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Introduction to Flapping Wing Aerodynamics

Download or read book An Introduction to Flapping Wing Aerodynamics written by Wei Shyy and published by Cambridge University Press. This book was released on 2013-08-19 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: For anyone interested in the aerodynamics, structural dynamics and flight dynamics of small birds, bats, insects and air vehicles (MAVs).

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 610 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.

Book Technical Information Indexes

Download or read book Technical Information Indexes written by United States. Naval Air Systems Command and published by . This book was released on 1975 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Applied Mechanics Reviews

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1992 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book NASA Scientific and Technical Publications

Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1990 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Modeling of Aircraft Unsteady Aerodynamic Characteristics Part 2 Parameters Estimated from Wind Tunnel Data

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...

Book Aeronautical Engineering

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: