Double-Ducted Fan as an Effective Lip Separation Control Concept for Vertical-Takeoff-and-Landing Vehicles

2021 ◽  
pp. 1-20
Author(s):  
Ali Akturk ◽  
Cengiz Camci
Keyword(s):  
Separation Control ◽  
Ducted Fan ◽  
Vertical Takeoff And Landing ◽  
Control Concept ◽  
Vertical Takeoff

Dynamic Analysis of a Ducted Fan UAV in Forward Flight

2012 ◽  
Vol 224 ◽  
pp. 510-513
Author(s):  
Wei Zhang ◽  
Ning Jun Fan
Keyword(s):  
Control System ◽  
System Design ◽  
Nonlinear Model ◽  
Control System Design ◽  
Forward Flight ◽  
Ducted Fan ◽  
Vertical Takeoff And Landing ◽  
Aerial Vehicle ◽  
And Control ◽  
Vertical Takeoff

This paper deals with the dynamic modeling of a ducted fan vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) and focuses on the dynamic characteristics analyzing in forward flight. A 6-DOF nonlinear model has been established in terms of the forces and moments and the model can be used in the structure and control system design.

scholarly journals Challenges and key requirements of batteries for electric vertical takeoff and landing aircraft

Joule ◽  
2021 ◽  
Author(s):  
Xiao-Guang Yang ◽  
Teng Liu ◽  
Shanhai Ge ◽  
Eric Rountree ◽  
Chao-Yang Wang
Keyword(s):  
Vertical Takeoff And Landing ◽  
Vertical Takeoff

Dynamics Simulation and Analysis of Transition Stage of Tilt-Rotor Aircraft

2016 ◽  
Vol 842 ◽  
pp. 251-258 ◽  
Author(s):  
Muhammad Rafi Hadytama ◽  
Rianto A. Sasongko
Keyword(s):  
Dynamic Response ◽  
Equations Of Motion ◽  
Flight Dynamics ◽  
Dynamics Simulation ◽  
Tilt Rotor ◽  
Vertical Takeoff And Landing ◽  
Improved Stability ◽  
Simulation Results ◽  
Vtol Aircraft ◽  
Vertical Takeoff

This paper presents the flight dynamics simulation and analysis of a tilt-rotor vertical takeoff and landing (VTOL) aircraft on transition phase, that is conversion from vertical or hover to horizontal or level flight and vice versa. The model of the aircraft is derived from simplified equations of motion comprising the forces and moments working on the aircraft in the airplane's longitudinal plane of motion. This study focuses on the problem of the airplane's dynamic response during conversion phase, which gives an understanding about the flight characteristics of the vehicle. The understanding about the flight dynamics characteristics is important for the control system design phase. Some simulation results are given to provide better visualization about the behaviour of the tilt-rotor. The simulation results show that both transition phases are quite stable, although an improved stability can give better manoeuver and attitude handling. Improvement on the simulation model is also required to provide more accurate and realistic dynamic response of the vehicle.

scholarly journals Power Line Charging Mechanism for Drones

Drones ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 108
Author(s):  
Boaz Ben-Moshe
Keyword(s):  
Homeland Security ◽  
Optimal Solution ◽  
Power Line ◽  
Flight Time ◽  
Security Applications ◽  
Long Duration ◽  
Vertical Takeoff And Landing ◽  
Charging Mechanism ◽  
Commercial Photography ◽  
Vertical Takeoff

The use of multirotor drones has increased dramatically in the last decade. These days, quadcopters and Vertical Takeoff and Landing (VTOL) drones can be found in many applications such as search and rescue, inspection, commercial photography, intelligence, sports, and recreation. One of the major drawbacks of electric multirotor drones is their limited flight time. Commercial drones commonly have about 20–40 min of flight time. The short flight time limits the overall usability of drones in homeland security applications where long-duration performance is required. In this paper, we present a new concept of a “power-line-charging drone”, the idea being to equip existing drones with a robotic mechanism and an onboard charger in order to allow them to land safely on power lines and then charge from the existing 100–250 V AC (50–60 Hz). This research presents several possible conceptual models for power line charging. All suggested solutions were constructed and submitted to a field experiment. Finally, the paper focuses on the optimal solution and presents the performance and possible future development of such power-line-charging drones.

Development of a Fuel Cell Hybrid Electric Vertical Takeoff and Landing Aircraft Power Train

2021 ◽  
Author(s):  
Mengxuan Wei ◽  
Maohang Qiu ◽  
Shuai Yang ◽  
Xiaoyan Liu ◽  
Jeff Taylor ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Cell Hybrid ◽  
Power Train ◽  
Vertical Takeoff And Landing ◽  
Hybrid Electric ◽  
Vertical Takeoff ◽  
Fuel Cell Hybrid

scholarly journals CReSIS airborne radars and platforms for ice and snow sounding

2019 ◽  
Vol 61 (81) ◽  
pp. 58-67 ◽  
Author(s):  
Emily Arnold ◽  
Carl Leuschen ◽  
Fernando Rodriguez-Morales ◽  
Jilu Li ◽  
John Paden ◽  
...  
Keyword(s):  
Unmanned Aerial Systems ◽  
Frequency Spectra ◽  
Radar Systems ◽  
Measurement Resolution ◽  
Vertical Takeoff And Landing ◽  
Specific Frequency ◽  
Platform Development ◽  
Aerial Systems ◽  
Future Work ◽  
Vertical Takeoff

AbstractThis paper provides an update and overview of the Center for Remote Sensing of Ice Sheets (CReSIS) radars and platforms, including representative results from these systems. CReSIS radar systems operate over a frequency range of 14–38 GHz. Each radar system's specific frequency band is driven by the required depth of signal penetration, measurement resolution, allocated frequency spectra, and antenna operating frequencies (often influenced by aircraft integration). We also highlight recent system advancements and future work, including (1) increasing system bandwidth; (2) miniaturizing radar hardware; and (3) increasing sensitivity. For platform development, we are developing smaller, easier to operate and less expensive unmanned aerial systems. Next-generation platforms will further expand accessibility to scientists with vertical takeoff and landing capabilities.

Distributed efficiency-based circular formation for the unmanned air vehicles detection system

2018 ◽  
Vol 233 (9) ◽  
pp. 3223-3234 ◽  
Author(s):  
Hu Zilun ◽  
Yang Jianying
Keyword(s):  
Detection Efficiency ◽  
Detection System ◽  
Unmanned Air Vehicles ◽  
Time Varying ◽  
Performance Function ◽  
Network Connection ◽  
Vertical Takeoff And Landing ◽  
Theoretical Results ◽  
Vertical Takeoff ◽  
Air Vehicles

This paper considers on the general circumnavigation problem for a team of vertical takeoff and landing unmanned air vehicles, with the goal of achieving specific circular formations and circling centered at a target of interest. Different from the traditional circular formation problem, in this paper, not only the formation but also the detection efficiency of the formation is taken into consideration. A novel distributed optimal circular formation algorithm is proposed. According to this algorithm, the circular formation can be guaranteed with the optimal radius that can optimize the team performance function. Hereon, the performance functions can be time-varying, and thus a time-varying optimal circular formation is created. Theoretical studies indicate that the proposed algorithm can achieve the formation in a distributed manner only based on the local information and the network connection. Finally, simulation examples are presented to show the validity of the theoretical results.

Interactions of Two UAV Rotors at Low Reynolds Number

2020 ◽  
Author(s):  
Yashvardhan Tomar ◽  
Dhwanil Shukla ◽  
Narayanan Komerath
Keyword(s):  
Reynolds Number ◽  
Electric Propulsion ◽  
Low Reynolds Number ◽  
Navier Stokes ◽  
Viscous Effects ◽  
Forward Flight ◽  
Spatial Spread ◽  
Vertical Takeoff And Landing ◽  
Low Reynolds ◽  
Vertical Takeoff

Abstract Vertical takeoff and landing vehicle platforms with many small rotors are becoming increasingly pertinent for small Unmanned Aerial Vehicles (UAVs) as well as distributed electric propulsion for larger vehicles. These rotors operate at low Reynolds number unlike large rotors for which the existing prediction methods were developed. Operating at very low Reynolds number essentially means that viscous effects are more dominant; and their spatial spread is significant with respect to the rotor dimensions. This impacts the nature of inter-rotor aerodynamic interactions which become more difficult to predict and characterize. In the present research, two nominally identical commercial UAV rotors are studied for a range of separations in hover and forward flight, both experimentally and computationally, in parallel with ongoing vehicle flight tests with 4 and 8 rotors. Bi-rotor tests in tandem in-plane configuration were performed in Georgia Tech’s 2.13m × 2.74m test section wind tunnel. Rotor simulations were done using the RotCFD Navier-Stokes solver. In hover, rotor performance is sensitive to the distance between rotors at low rotation speeds, indicating the presence of greater inter-rotor interactions at low Reynolds number. In forward flight, the performance of the downstream rotor gets negatively affected by the upstream rotor wake.

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