Performance Metrics Required of Next-Generation Batteries to Electrify Vertical Takeoff and Landing (VTOL) Aircraft

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.

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Military Vertical Takeoff and Landing (VTOL) Propulsion Systems Design

ASME 1972 International Gas Turbine and Fluids Engineering Conference and Products Show ◽

10.1115/72-gt-73 ◽

1972 ◽

Author(s):

A. O. Kohn

Keyword(s):

Low Power ◽

Systems Design ◽

Propulsion Systems ◽

Vertical Takeoff And Landing ◽

Power Setting ◽

Vtol Aircraft ◽

Vertical Takeoff ◽

Engine Size ◽

Maximum Thrust ◽

Selection Of

This paper deals with the parameters that must be considered in the selection and design of propulsion systems for military VTOL aircraft. Some of these parameters, for instance lightweight, are applicable to engines for all types of aircraft. For the VTOL aircraft, special emphasis must be placed on many of these parameters since aircraft takeoff gross weight determines engine size. Other significant considerations in the selection of the propulsion system include: (a) the ratio of subsonic cruise thrust to maximum thrust; and, (b) exhaust downwash characteristics. Consideration (a) is important because, in the case where no auxiliary lift engines or devices are used, subsonic cruise thrust is about 25 to 30 percent maximum, and at this low power setting, specific fuel consumption is increasing rapidly. Exhaust downwash characteristics are significant because of the variety of landing and takeoff sites likely to be encountered (i.e., shipboard or unprepared fields).

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Aircraft/Deck Interface Dynamics for Destroyers

Marine Technology and SNAME News ◽

10.5957/mt1.1987.24.1.15 ◽

1987 ◽

Vol 24 (01) ◽

pp. 15-25

Author(s):

Peter J. F. O'Reilly

Keyword(s):

Dynamic Analysis ◽

Research Program ◽

Interface Dynamics ◽

Analytical Technique ◽

Aircraft Landing ◽

Vertical Takeoff And Landing ◽

Time Histories ◽

Vtol Aircraft ◽

Vertical Takeoff

The interface between vertical takeoff and landing (VTOL) aircraft and destroyer and frigate-type warships involves a great many factors. This paper discusses a computer analytical technique which permits dynamic analysis of the aircraft landing or taking off from a moving deck or being handled or stowed on the ship. A condensed explanation of how the synthetic time histories are generated is contained in the Appendix. Two examples of how the technique has been used are included: first, a Recovery Assist and Secure System (RAS) analysis, and second, a pilot landing aid system, the Landing Period Designator (LPD) research program.

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Height of Spray Produced by Vertical Takeoff and Landing (VTOL) Aircraft,

10.21236/ada073099 ◽

1979 ◽

Author(s):

Richard E. Kuhn

Keyword(s):

Vertical Takeoff And Landing ◽

Vtol Aircraft ◽

Vertical Takeoff

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

Joule ◽

10.1016/j.joule.2021.05.001 ◽

2021 ◽

Author(s):

Xiao-Guang Yang ◽

Teng Liu ◽

Shanhai Ge ◽

Eric Rountree ◽

Chao-Yang Wang

Keyword(s):

Vertical Takeoff And Landing ◽

Vertical Takeoff

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Power Line Charging Mechanism for Drones

Drones ◽

10.3390/drones5040108 ◽

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.

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

10.1109/ecce47101.2021.9595968 ◽

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

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CReSIS airborne radars and platforms for ice and snow sounding

Annals of Glaciology ◽

10.1017/aog.2019.37 ◽

2019 ◽

Vol 61 (81) ◽

pp. 58-67 ◽

Cited By ~ 1

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.

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

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410018793764 ◽

2018 ◽

Vol 233 (9) ◽

pp. 3223-3234 ◽

Cited By ~ 1

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.

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Interactions of Two UAV Rotors at Low Reynolds Number

Volume 1: Fluid Applications and Systems; Fluid Measurement and Instrumentation ◽

10.1115/fedsm2020-20108 ◽

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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