Forced-Oscillation Test Mechanism for Measuring Dynamic-Stability Derivatives in Roll

1975 ◽  
Vol 12 (1) ◽  
pp. 11-17
Author(s):  
Glen E. Burt
Keyword(s):  
Dynamic Stability ◽  
Forced Oscillation ◽  
Stability Derivatives ◽  
Oscillation Test

scholarly journals Measurement of Dynamic Stability Derivatives of Tailless Lamda-shape UAV using Forced Oscillation Method

2016 ◽  
Vol 44 (7) ◽  
pp. 552-561
Author(s):  
Kwangjin Yang ◽  
Hyoungseog Chung ◽  
Donghyun Cho ◽  
Eunhye An ◽  
Joonsoo Ko ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Forced Oscillation ◽  
Stability Derivatives ◽  
Derivatives Of ◽  
Oscillation Method

Estimation and Separation of Longitudinal Dynamic Stability Derivatives with Forced Oscillation Method Using Computational Fluid Dynamics

Aerospace ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 354
Author(s):  
Nadhie Juliawan ◽  
Hyoung-Seog Chung ◽  
Jae-Woo Lee ◽  
Sangho Kim
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamic Stability ◽  
Forced Oscillation ◽  
Harmonic Oscillation ◽  
Test Model ◽  
Pitching Moment ◽  
Stability Derivatives ◽  
Oscillation Modes ◽  
Oscillation Method

This paper focuses on estimating dynamic stability derivatives using a computational fluid dynamics (CFD)-based force oscillation method, and on separating the coupled dynamic derivatives terms obtained from the method. A transient RANS solver is used to calculate the time history of aerodynamic moments for a test model oscillating about the center of gravity, from which the coupled dynamic derivatives are estimated. The separation of the coupled derivatives term is carried out by simulating simple harmonic oscillation motions such as plunging motion and flapping motion which can isolate the pitching moment due to AOA rate (Cmα˙) and the pitching moment due to pitch rate (Cmq), respectively. The periodic motions are implemented using a CFD dynamic mesh technique with user-defined function (UDF). For the validation test, steady and unsteady simulations are performed on the Army-Navy Finner Missile model. The static aerodynamic moments and pressure distribution, as well as the coupled dynamic derivative results from the pitching oscillation mode, show good agreement with the previously published wind tunnel tests and CFD analysis data. In order to separate the coupled derivative terms, two additional harmonic oscillation modes of plunging and flapping motions are tested with the angle of attack variations from 0 to 85 degrees at a supersonic speed to provide real insight on the missile maneuverability. The cross-validation study between the three oscillation modes indicates the summation of the individual plunging and flapping results becoming nearly identical to the coupled derivative results from the pitching motion, which implies the entire set of coupled and separated dynamic derivative terms can be effectively estimated with only two out of three modes. The advantages and disadvantages of each method are discussed to determine the efficient approach of estimating the dynamic stability derivatives using the forced oscillation method.

Determination of dynamic stability derivatives using forced oscillation technique

2002 ◽  
Author(s):  
N. Alemdaroglu ◽  
I. Iyigun ◽  
M. Altun ◽  
H. Uysal ◽  
F. Quagliotti ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Forced Oscillation ◽  
Forced Oscillation Technique ◽  
Stability Derivatives

Dynamic Stability of Hovercraft in Heave

1970 ◽  
Vol 37 (4) ◽  
pp. 895-900 ◽  
Author(s):  
H. J. Davies ◽  
G. A. Poland
Keyword(s):  
Mathematical Model ◽  
Dynamic Behavior ◽  
Dynamic Stability ◽  
Equilibrium Position ◽  
Forced Oscillation ◽  
Dynamic Equilibrium ◽  
Forced Oscillations ◽  
Two Dimensional ◽  
Oscillation Characteristics ◽  
Nonlinear Nature

The regimes of flow governing the dynamic behavior of a two-dimensional mathematical model of an edge-jet Hovercraft in heaving motion are described and the equations associated with such regimes derived. Both the free and forced-oscillation characteristics are studied. The nonlinear nature of the system manifests itself, in the case of the forced oscillations, as a shift in the dynamic equilibrium position resulting in a loss of mean hoverheight.

scholarly journals A numerical study into the longitudinal dynamic stability of the tailless aircraft

2019 ◽  
Vol 91 (3) ◽  
pp. 428-436 ◽  
Author(s):  
Agnieszka Kwiek
Keyword(s):  
Stability Analysis ◽  
Dynamic Stability ◽  
Numerical Study ◽  
Aircraft Design ◽  
Content Type ◽  
Preliminary Stage ◽  
Longitudinal Dynamic ◽  
Stability Derivatives ◽  
The Impact ◽  
Tailless Aircraft

Purpose The purpose of this research is a study into a mathematical approach of a tailless aircraft dynamic stability analysis. This research is focused on investigation of influence of elevons (elevator) on stability derivatives and consequently on the aircraft longitudinal dynamic stability. The main research question is to determine whether this impact should be taken into account on the conceptual and preliminary stage of the analysis of the longitudinal dynamic stability. Design/methodology/approach Aerodynamic coefficients and longitudinal stability derivatives were computed by Panukl (panel methods). The analysis of the dynamic stability of the tailless aircraft was made by the Matlab code and SDSA package. Findings The main result of the research is a comparison of the dynamic stability of the tailless aircraft for different approaches, with and without the impact of elevator deflection on the trim drag and stability derivatives. Research limitations/implications This paper presents research that mostly should be considered on the preliminary stage of aircraft design and dynamic stability analysis. The impact of elevons deflection on the aircraft moment of inertia has been omitted. Practical implications The results of this research will be useful for the further design of small tailless unmanned aerial vehicles (UAVs). Originality/value This research reveals that in case of the analysis of small tailless UAVs, the impact of elevons deflection on stability derivatives is bigger than the impact of a Mach number. This impact should be taken into consideration, especially for a phugoid mode.

Sign in / Sign up

Export Citation Format

Share Document