Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial Systems
Aerial drones have improved significantly over the recent decades with stronger and smaller motors, more powerful propellers, and overall optimization of systems. These improvements have consequently increased top speeds and improved a variety of performance aspects, along with introducing new struc...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-10-01
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| Series: | Drones |
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| Online Access: | https://www.mdpi.com/2504-446X/5/4/122 |
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| author | Anthony Quintana Rui Vasconcellos Glen Throneberry Abdessattar Abdelkefi |
| author_facet | Anthony Quintana Rui Vasconcellos Glen Throneberry Abdessattar Abdelkefi |
| author_sort | Anthony Quintana |
| collection | DOAJ |
| description | Aerial drones have improved significantly over the recent decades with stronger and smaller motors, more powerful propellers, and overall optimization of systems. These improvements have consequently increased top speeds and improved a variety of performance aspects, along with introducing new structural challenges, such as whirl flutter. Whirl flutter is an aeroelastic instability that can be affected by structural or aerodynamic nonlinearities. This instability may affect the prediction of potentially dangerous behaviors. In this work, a nonlinear reduced-order model for a nacelle-rotor system, considering quasi-steady aerodynamics, is implemented. First, a parametric study for the linear system is performed to determine the main aerodynamic and structural characteristics that affect the onset of instability. Multiple polynomial nonlinearities in the two degrees of freedom nacelle-rotor model are tested to simulate possible structural nonlinear effects including symmetric cubic hardening nonlinearities for the pitch and yaw degrees of freedom; purely yaw nonlinearity; purely pitch nonlinearity; and a combination of quadratic, cubic, and fifth-order nonlinearities for both degrees of freedom. Results show that the presence of hardening structural nonlinearities introduces limit cycle oscillations to the system in the post-flutter regime. Moreover, it is demonstrated that the inclusion of quadratic nonlinearity introduces asymmetric oscillations and subcritical behavior, where large and potentially dangerous deformations can be reached before the predicted linear flutter speed. |
| first_indexed | 2024-03-10T04:17:05Z |
| format | Article |
| id | doaj.art-7a7e997e3f9f4bbeba094d4fe3239b94 |
| institution | Directory Open Access Journal |
| issn | 2504-446X |
| language | English |
| last_indexed | 2024-03-10T04:17:05Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Drones |
| spelling | doaj.art-7a7e997e3f9f4bbeba094d4fe3239b942023-11-23T07:57:25ZengMDPI AGDrones2504-446X2021-10-015412210.3390/drones5040122Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial SystemsAnthony Quintana0Rui Vasconcellos1Glen Throneberry2Abdessattar Abdelkefi3Department of Mechanical and Aerospace Engineering, New Mexico State University, Las Cruces, NM 88003, USACampus of São João da Boa Vista, São Paulo State University (UNESP), São João da Boa Vista 13876-750, BrazilDepartment of Mechanical and Aerospace Engineering, New Mexico State University, Las Cruces, NM 88003, USADepartment of Mechanical and Aerospace Engineering, New Mexico State University, Las Cruces, NM 88003, USAAerial drones have improved significantly over the recent decades with stronger and smaller motors, more powerful propellers, and overall optimization of systems. These improvements have consequently increased top speeds and improved a variety of performance aspects, along with introducing new structural challenges, such as whirl flutter. Whirl flutter is an aeroelastic instability that can be affected by structural or aerodynamic nonlinearities. This instability may affect the prediction of potentially dangerous behaviors. In this work, a nonlinear reduced-order model for a nacelle-rotor system, considering quasi-steady aerodynamics, is implemented. First, a parametric study for the linear system is performed to determine the main aerodynamic and structural characteristics that affect the onset of instability. Multiple polynomial nonlinearities in the two degrees of freedom nacelle-rotor model are tested to simulate possible structural nonlinear effects including symmetric cubic hardening nonlinearities for the pitch and yaw degrees of freedom; purely yaw nonlinearity; purely pitch nonlinearity; and a combination of quadratic, cubic, and fifth-order nonlinearities for both degrees of freedom. Results show that the presence of hardening structural nonlinearities introduces limit cycle oscillations to the system in the post-flutter regime. Moreover, it is demonstrated that the inclusion of quadratic nonlinearity introduces asymmetric oscillations and subcritical behavior, where large and potentially dangerous deformations can be reached before the predicted linear flutter speed.https://www.mdpi.com/2504-446X/5/4/122whirl flutternonlinear dynamicsfluid-structure interactionrotor-nacelle systemunmanned aerial systems |
| spellingShingle | Anthony Quintana Rui Vasconcellos Glen Throneberry Abdessattar Abdelkefi Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial Systems Drones whirl flutter nonlinear dynamics fluid-structure interaction rotor-nacelle system unmanned aerial systems |
| title | Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial Systems |
| title_full | Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial Systems |
| title_fullStr | Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial Systems |
| title_full_unstemmed | Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial Systems |
| title_short | Nonlinear Analysis and Bifurcation Characteristics of Whirl Flutter in Unmanned Aerial Systems |
| title_sort | nonlinear analysis and bifurcation characteristics of whirl flutter in unmanned aerial systems |
| topic | whirl flutter nonlinear dynamics fluid-structure interaction rotor-nacelle system unmanned aerial systems |
| url | https://www.mdpi.com/2504-446X/5/4/122 |
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