Modeling of aircraft unsteady aerodynamic characteristics.

by Vladislav Klein

Publisher: National Aeronautics and Space Administration, Langley Research Center, Publisher: National Technical Information Service, distributor in Hampton, Va, [Springfield, Va

Written in English
Published: Downloads: 707
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Subjects:

  • Stability of airplanes.

Edition Notes

Modeling of Unsteady Aerodynamic Loads Determining the stability and control characteristics of aircraft at the edge of the envelope is one of the of different low-order models for representation of non-linear unsteady aerodynamic loads. In this view. @article{osti_, title = {Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD}, author = {Wolfe, W P and Ochs, S S}, abstractNote = {An investigation was conducted into the capabilities and accuracy of a representative computational fluid dynamics code to predict the flow field and aerodynamic characteristics of typical wind-turbine airfoils. Modeling and simulation method of unsteady aerodynamics on morphing wings were investigated. The Unsteady Vortex Lattice Method is employed to model the unsteady aerodynamics of 3-D potential flow field surrounding the wing. An UVLM computer code was then developed and validated for numerical simulation. A morphing wing which changes its dihedral angle with constant angular velocity was Cited by: 1. Modelling of unsteady aerodynamic characteristics for aircraft dynamics applicationsat high incidence flight. View/ Open. pdf (Mb) Date Author. Modelling of unsteady aerodynamic characteristics for aircraft dynamics applicationsat high incidence flight. View/ Open.

hypersonic vehicles is accurate and efficient modeling of the unsteady aerodynamic forces. Historically, due to the limited capa-bilities of computational facilities, past work has used a number of approximate unsteady aerodynamic theories, each of which assume inviscid flow and neglect real-gas effects [22–29]. ComputationalCited by:   Aerodynamicists use wind tunnels to test models of proposed aircraft and engine components. The model is placed in the test section of the tunnel and air is made to flow past the model. In some wind tunnel tests, the aerodynamic forces on the model are measured. In some wind tunnel tests, the model is instrumented to provide diagnostic information about the flow of air around the model. Flight Dynamics takes a new approach to the science and mathematics of aircraft flight, unifying principles of aeronautics with contemporary systems analysis. While presenting traditional material that is critical to understanding aircraft motions, it does so in the context of modern computational tools and multivariable methods. Rotary-wing flow fields are as complex as any in aeronautics. The helicopter rotor in forward flight encounters three-dimensional, unsteady, transonic, viscous aerodynamic phenomena. Rotary-wing problems provide a stimulus for development and opportunities for application of the most advanced computational techniques.

Unsteady aerodynamic models for agile flight at low Reynolds numbers Steven L. Brunton, Clarence W. Rowleyy Princeton University, Princeton, NJ The goal of this work is to develop low-order models for the unsteady aerodynamic forces on a small wing in response to agile maneuvers and gusts. total aircraft force coefficients. The products of the panel force coefficients and their moment arms with reference to a given axis are summed up to find the global aircraft moment coefficients. Two proposed variations of the state space representation of the basic unsteady aerodynamic model are identified using experimental aerodynamic dataCited by: 1. This is a book for those who seek to understand the fundamental principles underlying aircraft aerodynamic design. It won't provide much guidance relating to designing the details of a particular project but it is very illuminating about what general kind of /5(6).   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 Pages:

Modeling of aircraft unsteady aerodynamic characteristics. by Vladislav Klein Download PDF EPUB FB2

Modeling of Aircraft Unsteady Aerodynamic Characteristics Part I -Postulated Models Vladislav Klein and Keith D. Noderer The George Washington University, Joint Institute for Advancement of Flight Sciences, Langley Research Center, Hampton, Virginia (NASA-TM) MODELING OF AIRCRAFT UNSTEADY AERODYNAMIC CHARACTERISTICS.

PART i: POSTULATED File Size: KB. modeling of unsteady aerodynamics in the equations of motion and to estimation of aerodynamic parameters from experimental data.

In the first part of this series (reference 8), linear models for aerodynamic forces and moments were formulated. In the second part (reference 9), developed models were used in the analysis of wind tunnel data from File Size: 1MB.

A neural network approach for modeling of unsteady aerodynamic characteristics in a wide angle-of-attack range is considered in the paper. Special tests have been carried out in TsAGI wind tunnel.

The generation of reduced-order models for computing the unsteady and nonlinear aerodynamic loads on an aircraft from pitching motions in the transonic speed range is described. Add tags for "Modeling of aircraft unsteady aerodynamic characteristics. Part 3, Parameters estimated from flight data".

Part 3, Parameters estimated from flight data". Be the first. Present study is also focused on comparison of ROM for unsteady aerodynamics. Two NN architectures suitable for the reduced-order modeling of unsteady aerodynamic characteristics in the extended angle-of-attack range are considered, namely, a Feed-Forward Neural Network (FFNN) and a Cited by: 6.

An extended version of the Collar’s triangle shown in Figure 1 highlights the physical phenomena that need to be integrated for accurate modelling and simulation of flexible aircraft. Traditionally the flight dynamics community has focused on the link between inertial dynamics and aerodynamics and it assumes structural dynamics to occur at far higher frequencies than those of rigid-body Cited by: 3.

Time optimal maneuvers. An optimal control approach, is used to generate 6-DOF maneuvers for a generic UCAV. The feasible solutions are chosen based on the vehicle control and state constraints.

This approach finds the optimal controls that transfer a system from the initial state to the final state while minimizing (or maximizing) a specified cost by: nonlinear aerodynamic or fluid-structure interaction issues that were not discovered until flight testing.2 Some recent aircraft experiencing unexpected characteristics are the F/A, FE, and F,3 The lack of full understanding of unsteady aerodynamics typically leads.

A neural network approach for modeling of unsteady aerodynamic characteristics in a wide Modeling of aircraft unsteady aerodynamic characteristics. book range is considered in the paper.

Special tests have been carried out in TsAGI wind tunnel to investigate dynamic properties of unsteady aerodynamic characteristics of a generic transonic cruiser, which is a canard by: Get this from a library.

Modeling of aircraft unsteady aerodynamic characteristics. Part 1, Postulated models. [Vladislav Klein; Keith D Noderer; Langley Research Center.]. Unsteady aerodynamics modeling for aircraft maneuvers: A new approach using time-dependent A new approach for computing the unsteady and nonlinear aerodynamic loads acting on a maneuvering ble to accurately model aircraft static and dynamic characteristics (within the range of data used for model generation) from a num.

An important part of modeling the dynamics of a exible aircraft is its unsteady aerodynamics. Unsteady aerodynamics modeling, which involves computation of the forces exerted on a body in a time dependent air ow, has been important for reliable utter analysis.

There are Cited by: 9. General technique of modeling the unsteady aerodynamic characteristics uses the nonlinear indicial functions [5]. To develop the aerodynamics model based on the nonlinear indicial functions a large amount of unsteady aerodynamic data should be used.

Nevertheless, it requires a set of serious simplifications when. Flow over an aircraft at high angles of attack is characterized by a combination of separated and vortical flows that interact with each other and with the airframe.

As a result, there is a set of phenomena negatively affecting the aircraft’s performance, stability and control, namely, degradation of lifting force, nonlinear variation of pitching moment, positive damping, etc.

Wind tunnel Cited by: 6. Fig. Aircraft geometry schematization Fig. Vertical force and pitch moment derivatives BLWF software The BLWF software [3] is developed at TsAGI and is designed for calculation of unsteady aerodynamic characteristics of complex multi-element configurations which oscillate harmonically with small amplitudes in.

Presented is a frequency domain harmonic balance (HB) technique for modeling nonlinear unsteady aerodynamics of three-dimensional transonic inviscid flows about wing configurations. The method can be used to model efficiently nonlinear unsteady aerodynamic forces due to finite amplitude motions of a prescribed unsteady oscillation by: of the art in modeling unsteady nonlinear flow physics2 and offers an early and improved understanding and prediction of aircraft aerodynamic characteristics.

It is well known that unsteady aerodynamic forces and moments not only depend on the instantaneous states but also by all of the states at times prior to. In this paper, support vector machine (SVM) and artificial neural network are introduced into unsteady aerodynamics modeling.

The experimental results show that the generality and precision have been significantly improved using these two methods, which verifies that machine learning methods can be applied to unsteady aerodynamic by: 1.

In this paper, a reduced-order modeling approach based on computational fluid dynamics is presented for an elastic wing with control surfaces in the transonic regime. To treat the computational fluid dynamics grid around the geometrical discontinuities, due to the deflection of control surfaces, the constant volume tetrahedron method and the.

Indicial response modeling has recently been used for unsteady aerodynamic modeling of maneuvering aircraft [12,36–38]. In all these studies, the indicial functions were calculated only for aircraft states (e.g., angle of attack, side-slip angle, and angular rates), and simulations were performed on the clean configuration grid.

This. In view of engineering application, it is practicable to decompose the aerodynamics into three components: the static aerodynamics, the aerodynamic increment due to steady rotations, and the aerodynamic increment due to unsteady separated and vortical flow.

The first and the second components can be presented in conventional forms, while the third is described using a one-order Cited by: Comparison of Unsteady Aerodynamic Modelling Methodologies with respect to Flight Loads Analysis Thiemo M. Kier⁄ DLR German Aerospace Center, Institute of Robotics and Mechatronics, Wessling, Germany This paper addresses the development of aircraft models for °ight loads analysis in the pre-design stage.

Title of Dissertation: CFD Based Unsteady Aerodynamic Modeling for Rotor Aeroelastic Analysis Jayanarayanan Sitaraman, Doctor of Philosophy, Dissertation directed by: Associate Professor James D. Baeder Department of Aerospace Engineering A Computational Fluid Dynamics (CFD) analysis is developed for 3-D rotor unsteady aerodynamic load.

HALE UAVs developed in the past 30 years represent a wide range of flow conditions. From the low-speed Predator (Ernst, ) and Condor (Johnstone and Arntz, ) to Global Hawk (Heber, ) and Darkstar (Berman, ), these aircraft share several aerodynamic challenges, but also illustrate the differences among UAVs in this class.

Modeling the unsteady aerodynamic forces on small-scale wings The goal of this work is to develop low order dynamical systems models for the unsteady aerodynamic forces on small wings and to better understand the physical characteristics of unsteady laminar separation. Improved Boosting Model for Unsteady Nonlinear Aerodynamics based on Computational Intelligence: /IJCINI The large-amplitude-oscillation experiment was carried out with two levels of freedom to provide data.

Based on the wind tunnel data, polynomial regressionCited by: 1. Transition regime and its effects on the unsteady aerodynamic characteristics of a pitching airfoil. In, AIAA-Paper Keyword(s): Unsteady Aerodynamics, Laminar-to-Turbulent Transition, Nonlinear Aerodynamics, The Kutta Condition.

[bibtex-entry] P. Ripoll, A. Rezaei, and H. Taha. Modeling the unsteady aerodynamic forces on small-scale wings Steven L. Brunton, Clarence W. Rowleyy Princeton University, Princeton, NJ The goal of this work is to develop low order dynamical systems models for the unsteady aerodynamic forces on small wings and to better understand the physical characteristics of unsteady laminar Cited by: In this work, supersonic biplanes of the Busemann concept have been analysed, focusing on the unsteady aerodynamic characteristic due to flow disturbance using Computational Fluid Dynamics (CFD) codes in viscous flow.

Flow disturbance is modelled by sinusoidal pitch motion simulated by mesh morphing using radial basis functions (RBF) by: 2. The dynamic characteristics of an airplane is important in assessing its handling or flying qualities and for designing autopilots.

This paper investigates the dynamic characteristics of short take off and landing (STOL) airplanes employing root locus technique and state space approach.Time Domain Modeling of Unsteady Aerodynamic Forces on a Flapping Airfoil by Eric Durand Submitted to the Department of Aeronautics and Astronautics on May 8,in partial fulfillment of the requirements for the degree of Master of Science in Aeronautics and Astronautics Abstract.Unsteady Aerodynamic Modeling in Roll for the NASA Generic Transport Model.

Reducing the impact of loss-of-control conditions on commercial transport aircraft is a primary goal of the National Aeronautics and Space Administration (NASA) Aviation Safety Program.