Military Vertical Takeoff and Landing (VTOL) Propulsion Systems Design

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).

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

2018 ◽  
Vol 3 (12) ◽  
pp. 2989-2994 ◽  
Author(s):  
William L. Fredericks ◽  
Shashank Sripad ◽  
Geoffrey C. Bower ◽  
Venkatasubramanian Viswanathan
Keyword(s):  
Performance Metrics ◽  
Next Generation ◽  
Vertical Takeoff And Landing ◽  
Vtol Aircraft ◽  
Vertical Takeoff

Aircraft/Deck Interface Dynamics for Destroyers

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.

Lightweight unmanned aerial vehicle for emergency medical service – Synthesis of the layout

2020 ◽  
pp. 095441002091058 ◽  
Author(s):  
Tomasz Goetzendorf-Grabowski ◽  
Andrzej Tarnowski ◽  
Marcin Figat ◽  
Jacek Mieloszyk ◽  
Bogdan Hernik
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Forward Flight ◽  
Medical Mission ◽  
Emergency Medical ◽  
Vertical Takeoff And Landing ◽  
Aerial Vehicle ◽  
The Cost ◽  
Vertical Takeoff ◽  
Motor Failure ◽  
Selection Of

The article presents the innovative unmanned aerial vehicle project for emergency medical services. Designed unmanned aerial vehicle combines vertical takeoff and landing characteristics with fast forward flight capability that are vital to perform such an emergency medical mission. The main purpose of the designed unmanned aerial vehicle is to deliver the necessary medical package to the place where access is difficult, and estimated arrival time of conventional ambulance is too long. The cost of the support of such unmanned aerial vehicle could be significantly lower than in case of medical helicopter, which is not necessary in some cases. Designed unmanned aerial vehicle can also be used for fast delivery of essential medical substances (e.g. blood). The selection of configuration was the first and crucial step of the design. After analysis of many different copter configurations, together with selected crash reports analysis, the coaxial quadcopter configuration crossed with conventional airplane was selected. All power units for VTOL capability are electric, and they are doubled for redundancy purposes, with maximum T/W ratio about 2.0. Such configuration allows to sustain a stable flight (vertical phases) in case of one motor failure. Two versions of the vehicle are designed: fully electric (power units for the forward flight and vertical takeoff and landing are electric) and mixed where forward flight unit is a small piston engine. The final layout was the result of conceptual investigation and preliminary research, MDO and trade-off analysis, where as many aspects as possible were considered. The main problem was to meet the vertical takeoff and landing capabilities, relatively long range and endurance, expected payload (3 kg) and the requirement not to exceed 25 kg of maximum take-off weight. Paper presents the design process from initial requirement to the final configuration accepted to be manufactured.

scholarly journals Mutual Impact between Clock Gating and High Level Synthesis in Reconfigurable Hardware Accelerators

Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Francesco Ratto ◽  
Tiziana Fanni ◽  
Luigi Raffo ◽  
Carlo Sau
Keyword(s):  
Low Power ◽  
Integrated Circuit ◽  
Systems Design ◽  
Hardware Acceleration ◽  
High Level Synthesis ◽  
Clock Gating ◽  
Technology Application ◽  
Positive Effects ◽  
High Level ◽  
Different Levels

With the diffusion of cyber-physical systems and internet of things, adaptivity and low power consumption became of primary importance in digital systems design. Reconfigurable heterogeneous platforms seem to be one of the most suitable choices to cope with such challenging context. However, their development and power optimization are not trivial, especially considering hardware acceleration components. On the one hand high level synthesis could simplify the design of such kind of systems, but on the other hand it can limit the positive effects of the adopted power saving techniques. In this work, the mutual impact of different high level synthesis tools and the application of the well known clock gating strategy in the development of reconfigurable accelerators is studied. The aim is to optimize a clock gating application according to the chosen high level synthesis engine and target technology (Application Specific Integrated Circuit (ASIC) or Field Programmable Gate Array (FPGA)). Different levels of application of clock gating are evaluated, including a novel multi level solution. Besides assessing the benefits and drawbacks of the clock gating application at different levels, hints for future design automation of low power reconfigurable accelerators through high level synthesis are also derived.

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

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.

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