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High Altitude Long Endurance Air Vehicle Analysis of Alternatives and Technology Requirements DevelopmentThe objective of this study was to develop a variety of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV) conceptual designs for two operationally useful missions (hurricane science and communications relay) and compare their performance and cost characteristics. Sixteen potential HALE UAV configurations were initially developed, including heavier-than-air (HTA) and lighter-than-air (LTA) concepts with both consumable fuel and solar regenerative (SR) propulsion systems. Through an Analysis of Alternatives (AoA) down select process, the two leading consumable fuel configurations (one each from the HTA and LTA alternatives) and an HTA SR configuration were selected for further analysis. Cost effectiveness analysis of the consumable fuel configurations revealed that simply maximizing vehicle endurance can lead to a sub-optimum system solution. An LTA concept with a hybrid propulsion system (solar arrays and a hydrogen-air proton exchange membrane fuel cell) was found to have the best mission performance; however, an HTA diesel-fueled wing-body-tail configuration emerged as the preferred consumable fuel concept because of the large size and technical risk of the LTA concept. The baseline missions could not be performed by even the best HTA SR concept. Mission and SR technology trade studies were conducted to enhance understanding of the potential capabilities of such a vehicle. With near-term technology SR-powered HTA vehicles are limited to operation in favorable solar conditions, such as the long days and short nights of summer at higher latitudes. Energy storage system specific energy and solar cell efficiency were found to be the key technology areas for enhancing HTA SR performance.
Document ID
20070004936
Document Type
Conference Paper
Authors
Nickol, Craig L. (NASA Langley Research Center Hampton, VA, United States)
Guynn, Mark D. (NASA Langley Research Center Hampton, VA, United States)
Kohout, Lisa L. (NASA Glenn Research Center Cleveland, OH, United States)
Ozoroski, Thomas A. (Swales Aerospace Hampton, VA, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2007
Subject Category
Aircraft Design, Testing and Performance
Meeting Information
45th AIAA Aerospace Sciences Meeting and Exhibit(Reno, NV)
Funding Number(s)
WBS: WBS 561581.02.08.07
Distribution Limits
Public
Copyright
Public Use Permitted.

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