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.

Design of “Figure-8” Spherical Motion Flapping Wing for Miniature UAV

2009 ◽  
Author(s):  
Zohaib Rehmat ◽  
Jesse Roll ◽  
Joon S. Lee ◽  
Woosoon Yim ◽  
Mohamed B. Trabia
Keyword(s):  
Experimental Testing ◽  
Flapping Wing ◽  
Servo Motor ◽  
Flapping Motion ◽  
Experimental Prototype ◽  
Wing Motion ◽  
Air Vehicle ◽  
Spherical Motion

Hummingbirds and some insects exhibit a “Figure-8” flapping motion, which allows them to undergo variety of maneuvers including hovering. It is therefore desirable to have miniature air vehicle (FWMAV) with this wing motion. This paper presents a design of a flapping-wing for FWMAV that can mimic “Figure-8” motion using a spherical four bar mechanism. In the proposed design, the wing is attached to a coupler point on the mechanism, which is driven by a DC servo motor. A prototype is fabricated to verify that the design objectives are met. Experimental testing was conducted to determine the validity of the design. The results indicate good correlation between model and experimental prototype.

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 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>

Comparison of soot models for reacting sprays in diesel engine-like conditions

2021 ◽  
pp. 095440702110154
Author(s):  
Pavan Prakash Duvvuri ◽  
Rajesh Kumar Shrivastava ◽  
Sheshadri Sreedhara
Keyword(s):  
Experimental Data ◽  
Volume Fraction ◽  
Soot Volume Fraction ◽  
Modeling Framework ◽  
Aerosol Dynamics ◽  
Significant Difference ◽  
Polycyclic Aromatic ◽  
Order Of Magnitude ◽  
Detailed Kinetics ◽  
Soot Model

Stringent emission legislations and growing health concerns have contributed to the evolution of soot modeling in diesel engines from simple empirical relations to methods involving detailed kinetics and complex aerosol dynamics. In this paper, four different soot models have been evaluated for the high temperature, high pressure combusting dodecane spray cases of engine combustion network (ECN) spray A which mimics engine-relevant conditions. The soot models considered include an empirical, a multistep, a method of moments based, and a discrete sectional method soot model. Two experimental cases with ambient oxygen volume of 21% and 15% have been modeled. A good agreement between simulations and experiments for vapor penetration and heat release rate has been obtained. Quasi-steady soot volume fraction contours for the four soot models have been compared with experiments. Contours of the species and source terms involved in soot modeling have also been compared for a better understanding of soot processes. The empirical soot model results in higher magnitude and spread of soot due to a lack of modeling framework for oxidation through OH species. Among the four models studied, the multistep soot model has been observed to provide the most promising agreement with the experimental data in terms of distribution of soot and location of peak soot volume fraction. Due to a two-way coupling of soot models, the detailed models predict an upstream location for soot as compared to the multi-step soot model which is one way coupled. A significant difference (of an order of magnitude) in the concentration of PAH (polycyclic aromatic hydrocarbons) precursor between multistep and detailed soot models has been observed because of precursor consumption due to the coupling of detailed soot models with chemical kinetics. It is recommended that kinetic schemes, especially those concerning PAH, be validated with experimental data with a kinetics-coupled soot model.

Aerodynamic Model Updating Using Wind-Tunnel Setup for Hummingbirdlike Flapping Wing Nanorobot

AIAA Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Siemen Timmermans ◽  
Maarten Vanierschot ◽  
Dirk Vandepitte
Keyword(s):  
Wind Tunnel ◽  
Model Updating ◽  
Flapping Wing ◽  
Aerodynamic Model

scholarly journals Dove: A biomimetic flapping-wing micro air vehicle

2017 ◽  
Vol 10 (1) ◽  
pp. 70-84 ◽  
Author(s):  
Wenqing Yang ◽  
Liguang Wang ◽  
Bifeng Song
Keyword(s):  
Mechanism Design ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Flexible Wing ◽  
The Past ◽  
Ground Station ◽  
Air Vehicle ◽  
Research Goal ◽  
Color Video ◽  
Flapping Mechanism

This paper describes the design and development of the Dove, a flapping-wing micro air vehicle (FWMAV), which was developed in Northwestern Polytechnical University. FWMAVs have attracted international attentions since the past two decades. Since some achievements have been obtained, such as the capability of supporting an air vehicle to fly, our research goal was to design an FWMAV that has the ability to accomplish a task. Main investigations were presented in this paper, including the flexible wing design, the flapping mechanism design, and the on-board avionics development. The current Dove has a mass of 220 g, a wingspan of 50 cm, and the ability of operating fully autonomously, flying lasts half an hour, and transmitting live stabilized color video to a ground station over 4 km away.

Flight Characteristics of Flapping Wing Miniature Air Vehicles With “Figure-8” Spherical Motion

2009 ◽  
Author(s):  
Mohamed B. Trabia ◽  
Woosoon Yim ◽  
Zohaib Rehmat ◽  
Jesse Roll
Keyword(s):  
Mathematical Model ◽  
Wind Tunnel ◽  
Experimental Testing ◽  
Flapping Wing ◽  
Dynamic Stall ◽  
Wind Tunnel Testing ◽  
Servo Motor ◽  
Aerodynamic Forces ◽  
Flapping Motion ◽  
Spherical Motion

Hummingbirds and some insects exhibit “Figure-8” flapping motion that allows them to go through a variety of maneuvers including hovering. Understanding the flight characteristics of Figure-8 flapping motion can potentially yield the foundation of flapping wing UAVs that can experience similar maneuverability. In this paper, a mathematical model of the dynamic and aerodynamic forces associated with Figure-8 motion generated by a spherical four bar mechanism is developed. For validation, a FWMAV prototype with the wing attached to a coupler point and driven by a DC servo motor is created for experimental testing. Wind tunnel testing is conducted to determine the coefficients of flight and the effects of dynamic stall. The wing is driven at speeds up to 12.25 Hz with results compared to that of the model. The results indicate good correlation between mathematical model and experimental prototype.

Physical Essence of Stall Phenomena and its WNN-Based Aerodynamic Modeling from Flight Data

2014 ◽  
Vol 602-605 ◽  
pp. 3140-3143
Author(s):  
Xu Sheng Gan ◽  
Xue Qin Tang ◽  
Hai Long Gao
Keyword(s):  
Neural Network ◽  
Wavelet Neural Network ◽  
Flight Data ◽  
Numerical Examples ◽  
Aerodynamic Modeling ◽  
Aerodynamic Model ◽  
Aerodynamic Method ◽  
Physical Essence ◽  
Set Up

To understand the characteristics of aircraft stall for better aerodynamic model, the physical essence of the stall phenomena of aircraft is first introduced, and then a Wavelet Neural Network (WNN) is proposed to set up the stall aerodynamic model. Numerical examples indicates that through the deep cognition of the stall phenomena of aircraft the proposed stall aerodynamic method has a better accuracy than the traditional neural network and is also effective and feasible.

Validation and Parametric Investigations of an Internal Permanent Magnet Motor Using a Lumped Parameter Thermal Model

2021 ◽  
Author(s):  
Sebastien Sequeira ◽  
Kevin Bennion ◽  
J. Emily Cousineau ◽  
Sreekant Narumanchi ◽  
Gilberto Moreno ◽  
...  
Keyword(s):  
Experimental Data ◽  
Sensitivity Analysis ◽  
Permanent Magnet ◽  
Power Density ◽  
Heat Removal ◽  
Maximum Difference ◽  
Modeling Framework ◽  
Element Analysis ◽  
Lumped Parameter ◽  
Input Parameters

Abstract One of the key challenges for the electric vehicle industry is to develop high-power-density electric motors. Achieving higher power density requires efficient heat removal from inside the motor. In order to improve thermal management, a multi-physics modeling framework that is able to accurately predict the behavior of the motor, while being computationally efficient, is essential. This paper first presents a detailed validation of a Lumped Parameter Thermal Network (LPTN) model of an Internal Permanent Magnet synchronous motor within the commercially available Motor-CAD® modeling environment. The validation is based on temperature comparison with experimental data and with more detailed Finite Element Analysis (FEA). All critical input parameters of the LPTN are considered in detail for each layer of the stator, especially the contact resistances between the impregnation, liner, laminations and housing. Finally, a sensitivity analysis for each of the critical input parameters is provided. A maximum difference of 4% - for the highest temperature in the slot-winding and the end-winding - was found between the LPTN and the experimental data. Comparing the results from the LPTN and the FEA model, the maximum difference was 2% for the highest temperature in the slot-winding and end-winding. As for the LTPN sensitivity analysis, the thermal parameter with the highest sensitivity was found to be the liner-to-lamination contact resistance.

scholarly journals A Sub-100 mg Electromagnetically Driven Insect-inspired Flapping-wing Micro Robot Capable of Liftoff and Control Torques Modulation

2020 ◽  
Vol 17 (6) ◽  
pp. 1085-1095
Author(s):  
Chenyang Wang ◽  
Weiping Zhang ◽  
Yang Zou ◽  
Ran Meng ◽  
Jiaxin Zhao ◽  
...  
Keyword(s):  
Input Voltage ◽  
Flapping Wing ◽  
Total Weight ◽  
Voltage Amplitude ◽  
Torque Measurement ◽  
Electromagnetic Actuators ◽  
Aerodynamic Model ◽  
Micro Robot ◽  
The Mean ◽  
And Control

AbstractInspired by the unique, agile and efficient flapping flight of insects, we present a novel sub-100 mg, electromagnetically driven, tailless, flapping-wing micro robot. This robot utilizes two optimized electromagnetic actuators placed back to back to drive two wings separately, then kinematics of each wing can be independently controlled, which gives the robot the ability to generate all three control torques of pitch, roll and yaw for steering. To quantify the performance of the robot, a simplified aerodynamic model is used to estimate the generated lift and torques, and two customized test platforms for lift and torque measurement are built for this robot. The mean lift generated by the robot is measured to be proportional to the square of the input voltage amplitude. The three control torques are measured to be respectively proportional to three decoupled parameters of the control voltages, therefore the modulation of three control torques for the robot is independent, which is helpful for the further controlled flight. All these measured results fit well with the calculated results of the aerodynamic model. Furthermore, with a total weight of 96 mg and a wingspan of 3.5 cm, this robot can generate sufficient lift to take off.

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