| Author: | Shi, Lisong |
| Title: | The effects of the wing motion on the aerodynamics of a MAV |
| Degree: | M.Sc. |
| Year: | 2014 |
| Subject: | Airplanes -- Wings. Micro air vehicles. Hong Kong Polytechnic University -- Dissertations |
| Department: | Faculty of Engineering |
| Pages: | ix, 75 leaves : ill. (some col.) ; 30 cm. |
| Language: | English |
| Abstract: | This is an experimental study of aerodynamic performance of micro air vehicle (MAV), consists of four parts: (1) Particle Image Velocimetry Programming - Particle Image Velocimetry (PIV) is employed for instantaneous flow visualization; it is a complex system which can be influenced by multiple parameters; aside from the coordination among the equipment, different methodologies used in post-processing of the PIV image have distinct characteristic in both accuracy and efficiency; MATLAB codes for PIV is evaluated based on both Direct Discrete Correlation and Fast Fourier Transform methods, comparison between the two algorithms is analyzed. (2) Aerodynamics of a single flapping wing - Under zero free stream condition, complex instantaneous vortex topology is investigated for a flapping wing at half of the wing length, the cause-and-effect between vortex shedding and lift generation is analyzed; furthermore, vortex topology with flapping frequencies of 8Hz and 12Hz is studied qualitatively for its impact on instantaneous lift. (3) The process of Clap-Fling motion - As an important and also complicated feature of insects flying, Clap-Fling motion is engaged in the design of current MAV. Experiment is conducted at 10Hz with zero free stream, the vortices distributions surrounding the Clap-Fling mechanism developed from the averaged PIV data at successive moments of one cycle unveil a number of important aspects of the Clap-Fling. (4) The wake behind MAV - For the MAV in this research, the corresponding angle of attack with certain flow velocity is carefully selected based on the horizontal component of the time-averaged force equals to zero, which indicates the ideal situation for level flying. With the appropriate condition for level flying, the evolution of the flow structure in the downstream of the MAV is analyzed in correlation with the lift measurement, to release the concealed physics for MAV. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b27474975.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 10 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/7441