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Journal Article

Demonstration of a Compact Hydrogen Fuel Cell Power System for UAS Propulsion

2014-09-16
2014-01-2223
We have assembled and demonstrated a prototype power system that uses an innovative hydrogen generator to fuel an ultra-compact PEM fuel cell that is suitable for use in small unmanned aerial system (UAS) propulsion systems. The hydrogen generator uses thermal decomposition of ammonia borane (AB) to produce hydrogen from a very compact and lightweight package. ...The fuel cell plant utilized in the power system prototype has been flown as part of several small UAS development programs and has logged hundreds of hours of flight time. The plant was designed specifically to be readily integrated with a range of hydrogen fueling subsystems and contains the balance of plant necessary to facilitate stand-alone operation.
Article

Advanced simulation using the digital twin to achieve electromagnetic compatibility and electrification management in a modern UAS

2022-01-13
The aerospace industry is facing immense challenges due to increased design complexity and higher levels of integration, particularly in the electrification of aircraft. These challenges can easily impact program cost and product time to market. System electrification and electromagnetic compatibility (EMC) have become critical issues today. In the context of 3D electromagnetics, EMC electromagnetic compatibility ensures the original equipment manufacturer (OEM) that radiated emissions from various electronic devices, such as avionics or the entire aircraft for that matter, do not interfere with other electronic products onboard the aircraft.
Technical Paper

Development of Small Internal Combustion Engine Thrust Stand/Dynamometer

2010-04-12
2010-01-0658
Current US military small unmanned aircraft systems (UAS) rely on engines and propellers sourced from the hobby radio-controlled (RC) aircraft industry. ...Torque, thrust, power, brake specific fuel consumption, (BSFC) and propeller efficiency data for a UAS engine are presented.
Journal Article

Projecting the Impact of Aircraft Design Decisions on the Performance of a Fuel Cell Power and Energy System in Unmanned Aircraft Systems

2012-10-22
2012-01-2178
Fuel Cells provide an attractive alternative to battery powered Unmanned Aircraft Systems (UAS) as they maintain the simplicity of an all-electric vehicle architecture while taking advantage of highly energy-dense fuels. ...These outside requirements play a particularly important role in the design of Small UAS (SUAS) P&E systems where the fixed weight of the fuel cell plant may approach or exceed the weight of the fuel utilized. ...As the UAS design concept matures additional dependencies emerge, particularly due to the impact of mission requirements such as the required environmental operating envelope.
Journal Article

Hybrid-Electric, Heavy-Fuel Propulsion System for Small Unmanned Aircraft

2014-09-16
2014-01-2222
A series hybrid-electric propulsion system has been designed for small rapid-response unmanned aircraft systems (UAS) with the goals of improving endurance, providing flexible and responsive electric propulsion, and enabling heavy fuel usage. ...An energy-dense rechargeable battery pack was used to store energy and allow the UAS to operate with the engine shut off, which provided an engine-off operating mode. The ISA allowed re-starting the engine in flight without the need for a separate starter motor. ...The series hybrid UAS outfitted with the custom diesel engine demonstrated endurance improvements, due to additional benefits netted from the improved engine efficiency.
Magazine

Aerospace & Defense Technology: October 2022

2022-10-01
Optimal UAS Assignments and Trajectories for Persistent Surveillance and Data Collection from a Wireless Sensor Network Developing a methodology for multiple unmanned aircraft assigned to fly optimal trajectories in order to survey and collect a pre-specified amount of data from a fixed, ground-based wireless sensor network.
Journal Article

Real-Time Powertrain Models of Hybrid Electric Vehicles

2014-10-13
2014-01-2893
Hybrid electric powertrains are developed for reducing the fuel consumption and consequently the emission of carbon dioxide. The fuel consumption of those systems depends significantly on the topology of the powertrain and the applied control strategy. For testing and improving the control strategy in terms of the overall system efficiency, Hardware-in-the-Loop (HIL) simulation can be applied. In order to operate the corresponding electronic control units in a virtual environment, it emulates the behavior of the actuator and sensor signals by a real-time simulation of the powertrain. Developing those powertrain models is a time-consuming task, due to high dynamics and high switching frequencies of the electrical subsystem and due to the large diversity of powertrain configurations.
Technical Paper

Emission Reduction Potential by Means of High Boost and Injection Pressure at Low- and Mid-Load for a Common Rail Diesel Engine under High EGR Rates

2013-10-14
2013-01-2541
The emission reduction potential of high boost and high injection pressures was investigated on a 4-cylinder small bore diesel engine at high rates of exhaust gas recirculation. For this reason an external boosting system was built up, which allowed to generate the desired boost pressure independent from the engine's operating point. In order to simulate conditions comparable to a real turbocharged engine, also the influence of the turbine on the exhaust back pressure was considered. The whole measurement campaign was carried out at two load points (low- and mid-load), which represent characteristic engine operating points of the Urban Driving Cycle (UDC). On the one hand could be shown, that there is an enormous potential in the reduction of particulate matter (PM) up to 75 % and of carbon monoxide (CO) up to 15 % at the mid-load point by increasing the boost pressure.
Journal Article

A New Measurement Technique for Online Oil Dilution Measurement

2013-10-14
2013-01-2521
New trends in the development of combustion engines lead to changed engine operating conditions which also result in changed loads of the engine parts and functional components. The application of regenerative fuels and new exhaust after- treatment systems can for example lead to an increased input of fuel into the engine oil. Oil dilution is an issue that impacts the engine operation and life cycle and therefore gains importance during the development process of combustion engines. In order to improve oil dilution to preclude destructive amounts of fuel in the oil it is necessary to investigate and optimize the fuel in oil sorption and desorption processes. At the University of Applied Sciences Regensburg a new measurement technique has been developed that realizes the online analysis of the fuel quantity in the engine oil.
Standard

UxS Control Segment (UCS) Architecture: UCTRACE

2024-01-10
WIP
AIR6519A
This document is the SAE publication of the Department of Defense UAS Control Segment (UCS) Architecture: Use Case Trace (UCTRACE) Version 3.4(PR) approved for Distribution A public release 15.S-1859.
Technical Paper

FMS and AFCS Interface for 4D Trajectory Operations

2015-09-15
2015-01-2458
The future revolution of the air traffic system imposes the development of a new class of Flight Management Systems (FMS), capable of providing the aircraft with real-time reference flight parameters, necessary to fly the aircraft through a predefined sequence of waypoints, while minimizing fuel consumption, noise and pollution emissions. The main goal is to guarantee safety operations while reducing the aircraft environmental impact, according to the main international research programs. This policy is expected to affect also the Unmanned Aerial Systems (UASs), as soon as they will be allowed to fly beyond the restricted portions of the aerospace where they are currently confined. In the future, in fact, UASs are expected to fly within the whole civilian airspace, under the same requirements deriving from the adoption of the Performance Based Navigation (PBN).
Technical Paper

Simulation, Sizing and Analysis of High Pressure Hydrogen All Electrochemical Decentralized Refueling Station

2016-04-05
2016-01-1183
The University of Applied Sciences Esslingen (UASE) is a partner in the collaborative EU project PHAEDRUS (high Pressure Hydrogen All Electrochemical Decentralized RefUeling Station) as part of the EU work programme SP1-JTI-FCH.2011.1.8 Research and Development of 700 bar refueling concepts and technologies. The subtask of UASE is the simulation, sizing and analysis of a new concept for a 100 MPa hydrogen refueling station enabling self-sustained infrastructure roll-out for early vehicle deployment volumes, showing the applicability of the electrochemical hydrogen compression (EHC) technology in combination with an on-site anion exchange membrane electrolyser (AEMEC), storage units, precooling and a dispensing system. The electrolyser and the compressor are modeled using the electrochemical equations and the conservation of mole balance.
Book

Advances in Electric Propulsion

2017-05-18
Aviation propulsion development continues to rely upon fossil fuels for the vast majority of commercial and military applications. Until these fuels are depleted or abandoned, burning them will continue to jeopardize air quality and provoke increased regulation. With those challenges in mind, research and development of more efficient and electric propulsion systems will expand. Fuel-cell technology is but one example that addresses such emission and resource challenges, and others, including negligible acoustic emissions and the potential to leverage current infrastructure models. For now, these technologies are consigned to smaller aircraft applications, but are expected to mature toward use in larger aircraft. Additionally, measures such as electric/conventional hybrid configurations will ultimately increase efficiencies and knowledge of electric systems while minimizing industrial costs.
Magazine

Aerospace & Defense Technology: May 2020

2020-05-01
Connectors Lighten the SWaP Burden in UAV/MUMT Aircraft Electronics Playing Defense Uncertain Regulations Stall the Implementation of Counter-UAS Technology in The U.S. Drone Swarms A Transformational Technology Robotic Combat Vehicles Putting the Brains Behind the Brawn Effectiveness of Inter-Vehicle Communications and On-Board Processing for Close Unmanned Autonomous Vehicle Flight Formations Developing an effective cooperative communication system for unmanned aerial vehicles can increase their autonomy, reduce manpower requirements, and improve mission capabilities. Systems Engineering Approach to Develop Guidance, Navigation and Control Algorithms for Unmanned Ground Vehicle This research explores the development of a UGV capable of operating autonomously in a densely cluttered environment such as the tropical jungles or plantation estates commonly found in Asia.
Magazine

AEROSPACE ENGINEERING 2013-10

2013-10-01
High hopes or just dreaming? A look at how Asia's aircraft manufacturers are trying to break into new markets to challenge the status quo. Camelina-based biofuel shows advantages in turboprop Researchers within the government of Canada see the need to improve the emissions performance of the Rolls-Royce T56 engine, which despite its age remains a workhorse for its military aircraft fleet.
Magazine

Aerospace & Defense Technology: October 2021

2021-10-01
Developing Object Detection Systems for Autonomous Underwater Vehicles Developing Thermoplastic Composites for Use in Commercial Aircraft An Automated System for Multi-Physics Modeling Taking the Tactical Cloud with You Small Form Factor, Modular Data Centers at the Edge of the Battlefield Remanufacturing Reimagined How Selective Electroplating Extends Service Life and Reduces the Cost of Aerospace Components Satellite Paves the Way for Improved Storm Tracking Solar-Powered Satellite Hardware in Orbit Impact of Satellite Intelligence, Surveillance and Reconnaissance on Modern Naval Operations Determining whether afloat availability of satellite ISR, a technology that is relatively new, fundamentally changed naval operations and if so, to what degree. 3D Data Acquisition Platform for Human Activity Understanding Implementing motion capture devices, 3D vision sensors, and EMG sensors to cross validate multi-modality data acquisition and address fundamental research problems involving the representation and invariant description of 3D data, human motion modeling and applications of human activity analysis, and computational optimization of large-scale 3D data.
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