An aeroelastic analysis of a flexible flapping wing using modified strip theory

2008 ◽  
Author(s):  
Dae-Kwan Kim ◽  
Jun-Seong Lee ◽  
Jin-Young Lee ◽  
Jae-Hung Han
Keyword(s):  
Flapping Wing ◽  
Aeroelastic Analysis ◽  
Strip Theory

scholarly journals Improving Prediction of Flapping-Wing Motion By Incorporating Actuator Constraints With Models of Aerodynamic Loads Using In-Flight Data

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
John W. Gerdes ◽  
Hugh A. Bruck ◽  
Satyandra K. Gupta
Keyword(s):  
Experimental Data ◽  
Design Space Exploration ◽  
Experimental Testing ◽  
Flapping Wing ◽  
Modeling Framework ◽  
Flight Data ◽  
Flexible Wing ◽  
Wing Motion ◽  
Aerodynamic Model ◽  
Strip Theory

Flapping-wing flight is a challenging system integration problem for designers due to tight coupling between propulsion and flexible wing subsystems with variable kinematics. High fidelity models that capture all the subsystem interactions are computationally expensive and too complex for design space exploration and optimization studies. A combination of simplified modeling and validation with experimental data offers a more tractable approach to system design and integration, which maintains acceptable accuracy. However, experimental data on flapping-wing aerial vehicles which are collected in a static laboratory test or a wind tunnel test are limited because of the rigid mounting of the vehicle, which alters the natural body response to flapping forces generated. In this study, a flapping-wing aerial vehicle is instrumented to provide in-flight data collection that is unhindered by rigid mounting strategies. The sensor suite includes measurements of attitude, heading, altitude, airspeed, position, wing angle, and voltage and current supplied to the drive motors. This in-flight data are used to setup a modified strip theory aerodynamic model with physically realistic flight conditions. A coupled model that predicts wing motions is then constructed by combining the aerodynamic model with a model of flexible wing twist dynamics and enforcing motor torque and speed bandwidth constraints. Finally, the results of experimental testing are compared to the coupled modeling framework to establish the effectiveness of the proposed approach for improving predictive accuracy by reducing errors in wing motion specification.

scholarly journals Multidisciplinary design optimization of the flapping wing system for forward flight

2017 ◽  
Vol 9 (2) ◽  
pp. 93-110
Author(s):  
Jung-Sun Choi ◽  
Gyung-Jin Park
Keyword(s):  
Design Optimization ◽  
Design Process ◽  
Multidisciplinary Design Optimization ◽  
Flapping Wing ◽  
Multidisciplinary Design ◽  
Vehicle Model ◽  
Thrust Coefficient ◽  
Analysis And Design ◽  
Aeroelastic Analysis ◽  
Air Vehicle

The success of a flapping wing air vehicle flight is strongly related to the flapping motion and wing structure. Various disciplines should be considered for analysis and design of the flapping wing system. A design process for a flapping wing system is defined by using multidisciplinary design optimization. Unsteady aeroelastic analysis is employed as the system analysis. From the results of the aeroelastic analysis, the deformation of the wing is transmitted to the fluid discipline and the dynamic pressure is conveyed to the structural discipline. In the fluid discipline, a kinematic optimization problem is solved to maximize the time-averaged thrust coefficient and the propulsive efficiency simultaneously. In the structural discipline, nonlinear dynamic topology optimization is performed to find the distribution of reinforcement by using the equivalent static loads method for nonlinear static response structural optimization. The defined design process is applied to a flapping wing air vehicle model and the flapping wing air vehicle model is fabricated based on the optimization results.

Generic Modeling and Parametric Study of Flapping Wing Micro-Air-Vehicle

2012 ◽  
Vol 225 ◽  
pp. 18-25 ◽  
Author(s):  
Harijono Djojodihardjo ◽  
Alif Syamim Syazwan Ramli ◽  
Surjatin Wiriadidjaja
Keyword(s):  
Parametric Study ◽  
Three Dimensional ◽  
Unsteady Aerodynamics ◽  
Flapping Wing ◽  
Phase Lag ◽  
Aerodynamic Model ◽  
Strip Theory ◽  
Thrust Characteristics ◽  
Generic Modeling ◽  
Wing Geometry

The present work is focused on the unsteady aerodynamics of bio-inspired flapping wing to produce lift and thrust for hovering and forward flight. A generic approach is followed to understand and mimic the mechanism and kinematics of ornithopter by considering the motion of a three-dimensional rigid thin wing in flapping and pitching motion, using strip theory and two-dimensional unsteady aerodynamics for idealized wing in pitching and flapping oscillations with phase lag. Parametric study is carried out to obtain the lift, drag, and thrust characteristics within a cycle for assessing the plausibility of the aerodynamic model, and for the synthesis of a Flapping Wing MAV model with simplified mechanism. Other important parameters such as flapping frequency and wing geometry are considered. Results are assessed in comparison with the existing theoretical results.

scholarly journals Aeroelastic Analysis of a Flapping Blow Fly Wing

2020 ◽  
Vol vm01 (is01) ◽  
pp. 14-21
Author(s):  
Can Beker ◽  
Ali Emre Turgut ◽  
Kutluk Bilge Arikan ◽  
Dilek Funda Kurtulus
Keyword(s):  
Fluid Dynamics ◽  
3D Model ◽  
Input Function ◽  
Flapping Wing ◽  
Blow Fly ◽  
Structural Dynamic ◽  
Aeroelastic Analysis ◽  
Sinusoidal Input ◽  
Computational Fluid Dynamics Cfd ◽  
Analysis Models

In this study, a 3D model of the bio-inspired blowfly wing Callphere Erytrocephala is created and aeroelastic analysis is performed to calculate its aerodynamical characteristics by use of numerical methods. To perform the flapping motion, a sinusoidal input function is created. The scope of this study is to perform aeroelastic analysis by synchronizing computational fluid dynamics (CFD) and structural dynamic analysis models and to investigate the unsteady lift formation on the aeroelastic flapping wing for different angles of attack.

scholarly journals Further Development of the Kinematic and Aerodynamic Modeling and Analysis of Flapping Wing Ornithopter from Basic Principles

2014 ◽  
Vol 629 ◽  
pp. 9-17
Author(s):  
Harijono Djojodihardjo ◽  
Muhammad Anas Abd Bari ◽  
Azmin Shakrine Mohd Rafie ◽  
Surjatin Wiriadidjaja
Keyword(s):  
Three Dimensional ◽  
Unsteady Aerodynamics ◽  
Flapping Wing ◽  
Phase Lag ◽  
Basic Principles ◽  
Modeling And Analysis ◽  
Aerodynamic Modeling ◽  
Aerodynamic Model ◽  
Strip Theory ◽  
Further Development

<p>The basis of this work was to understand the generation of lift and thrust of a flapping bi-wing ornithopter, which is influenced by its geometrical, dynamic, kinematic and aerodynamic features by following a generic approach in order to identify and mimic the mechanisms. As further development of earlier work, three-dimensional rigid thin wing is considered in flapping and pitching motion using strip theory and two-dimensional unsteady aerodynamics for idealized wing in pitching and flapping oscillations with phase lag. Later, parametric study is carried out to attain a complete cycle’s lift and thrust physical characteristics for evaluating the plausibility of the aerodynamic model and for the synthesis of an ornithopter model with simplified mechanism. Further investigation is conducted to identify individual contribution of generic motion towards the flight forces. Results are assessed in comparison with existing theoretical and experimental results as appropriate.</p>

FLUID-STRUCTURE INTERACTION ANALYSIS OF HINGELESS ROTOR BLADES IN HOVER CONSIDERING WAKE EFFECTS

2010 ◽  
Vol 24 (13) ◽  
pp. 1475-1478 ◽  
Author(s):  
SEUNG-JAE YOO ◽  
MIN-SOO JEONG ◽  
IN LEE
Keyword(s):  
Interaction Analysis ◽  
Damping Ratio ◽  
Three Dimensional ◽  
Beam Theory ◽  
Rotor Blades ◽  
Aeroelastic Stability ◽  
Lattice Method ◽  
Aeroelastic Analysis ◽  
Strip Theory ◽  
Wake Effects

Aeroelastic analysis of hingeless rotor blades in hover was performed. Large deflection beam theory was applied to analyze blade motions with effects of geometric structural nonlinearity. Aerodynamic loads for aeroelastic analysis were calculated through a three-dimensional aerodynamic model which is based on the unsteady vortex lattice method. Wake geometry was described using a time-marching free-wake method. Lead-lag damping ratio and frequency were calculated to evaluate aeroelastic stability of hingeless rotor system. Numerical results of aeroelastic analysis for hingeless rotor blades were presented and compared with results based on experimental data and two-dimensional quasi-steady strip theory in which uniform inflow model was used. It was shown that wakes significantly affect the steady-state deflections and aeroelastic stability.

Sizing process, aerodynamic analysis, and experimental assessment of a biplane flapping wing nano air vehicle

2019 ◽  
Vol 233 (15) ◽  
pp. 5618-5636 ◽  
Author(s):  
Mehdi Ghommem ◽  
Mostafa Hassanalian ◽  
Majed Al-Marzooqi ◽  
Glen Throneberry ◽  
Abdessattar Abdelkefi
Keyword(s):  
Flight Test ◽  
Flapping Wing ◽  
Smooth Transition ◽  
Magnetic Coils ◽  
Strip Theory ◽  
Air Vehicle ◽  
Applied Design ◽  
The Stability ◽  
Design And Manufacture ◽  
Nano Air Vehicle

The design, manufacturing, experimentation, performance analysis, and flight test for a biplane flapping wing nano air vehicle, capable of both forward and hovering flight are presented. To design this nano air vehicle, a comprehensive sizing method based on theoretical and statistical analyses is proposed and experimentally verified. Then, aerodynamic analyses based on quasi-steady and strip theory methods are conducted to select the optimum values for the kinematics. To evaluate the proposed conceptual design obtained from the sizing methodology and aerodynamic analyses, an experimental setup deploying strain gauges mounted on a thin aluminum plate is implemented. This setup is also deployed to identify the wing configuration resulting in the highest thrust generation and lowest power consumption. The experimental results are found in a good agreement with the aerodynamic simulations. To ensure the stability of the air vehicle and a smooth transition between the different flying modes, magnetic coils are mounted on the tail to actuate the elevator and rudder. A flight test was successfully performed indoor to demonstrate the flying capabilities of the air vehicle and the camera showed a clear visual inspection of the area. It showed stable behavior especially during the transition from forward flight to hovering and superior flight endurance in comparison to similar air vehicles reported in the literature. The proposed and applied design methodologies along with the manufacturing process are expected to provide useful guidelines to design and manufacture different types of flapping wings to support various applications.

scholarly journals A Parametric Study on the Aeroelasticity of Flared Hinge Folding Wingtips

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 221
Author(s):  
Rafic M. Ajaj ◽  
Erick I. Saavedra Flores ◽  
Mohammadreza Amoozgar ◽  
Jonathan E. Cooper
Keyword(s):  
Parametric Study ◽  
Nonlinear Behavior ◽  
Aerodynamic Load ◽  
Aeroelastic Response ◽  
Beam Elements ◽  
Aeroelastic Analysis ◽  
Aeroelastic Model ◽  
Strip Theory ◽  
Line Angle ◽  
Tip Mass

This paper presents a parametric study on the aeroelasticity of cantilever wings equipped with Flared Hinge Folding Wingtips (FHFWTs). The finite element method is utilized to develop a computational, low-fidelity aeroelastic model. The wing structure is modelled using Euler–Bernoulli beam elements, and unsteady Theodorsen’s aerodynamic strip Theory is used for aerodynamic load predictions. The PK method is used to estimate the aeroelastic boundaries. The model is validated using three rectangular, cantilever wings whose properties are available in literature. Then, a rectangular, cantilever wing is used to study the effect of folding wingtips on the aeroelastic response and stability boundaries. Two scenarios are considered for the aeroelastic analysis. In the first scenario, the baseline, rectangular wing is split into inboard and outboard segments connected by a flared hinge that allows the outboard segment to fold. In the second scenario, a folding wingtip is added to the baseline wing. For both scenarios, the influence of fold angle, hinge-line angle (flare angle), hinge stiffness, tip mass and geometry are assessed. In addition, the load alleviation capability of FHFWT is evaluated when the wing encounters discrete (1-cosine) gusts. Finally, the hinge is assumed to exhibit cubic nonlinear behavior in torsion, and the effect of nonlinearity on the aeroelastic response is assessed and analyzed for three different cases.

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