Alternative Lift Gases Presented to: Joint AIAA / AUVSI Technical Session: “Emerging Trends in Tethered Systems” Washington, D.C. August 12, 2013
Skynet over Frisco, TX
In the Beginning… • Montgolfier Bro’s • Hot Air Balloons • 14 Dec. 1782 • Coated Tafetta o ~500 lbs. EW o 28,000 cubic feet o and 1,800 buttons • Tethered Flight! o Unmanned • Manned Oct 1783 • 70,000 Cubic feet
Early LTA Flight • Mssrs. Charles & Robert • Flew December 1, 1783 • Hydrogen Gas Balloons o “Better flying w/ chemistry ” o Veritable “Space Race” • Government-Sponsored o Viva la France • Gas balloons dominate • Chemical H2 generation o H2SO4 + (Fe, Zn) >>>(H2)
Early LTA Flight • No other manned flight until Wrights (1903) • Balloon uses: o Recce’ o Recreation o Advertising • Very Popular
Early LTA Flight
Early LTA Flight
Early LTA Flight
May 6, 1937…
T he VERY Beginning… • “Big Bang” created elements via nucleosynthesis o Hydrogen, Helium two most common elements • Followed in order by Oxygen, Neon, Carbon, Silicon • Factoid: Trace Helium is found trapped in some meteorites • Sun burns Helium: He is much rarer here on earth • Helium is found together with natural gas o Product of decaying radioactive rock (nucleosynthesis) accumulated over the course of gazillions of years • U.S. “refines” He from Natural Gas by cooling it o NG may contain as much as 1.5% He o U.S. refines and controls some 75% of world’s supply
Scientific American
I’m your Density… Temp. Density Lift (N/m 3 ) Safety Cost Ease of Buoyancy GAS M.W. ( ° C) (kg/m 3 ) in ISA provision control H 2 2 15 ° 0.084 11.19 bad fair fair no very very He 4 0.169 10.36 good no 15 ° high bad CH 4 16 15 ° 0.676 5.39 bad low fair no NH 3 17 0.718 4.97 fair low fair no 15 ° 29 0.921 2.98 very 110 ° hot air good good yes (avg) (avg) (avg) low (avg) very steam 18 0.587 6.26 good good yes 100 ° low (H 2 O)
Let’s just s ay No to Helium… • Helium becoming prohibitively expensive o Helium prices -will- continue to climb steadily • Helium vital for many other applications: o MRI machines currently use ~44% of Helium • BTW: He for lift gas applications constitute <~6% total o Leak detection requires the smaller He molecule • Helium can never be generated “on - site” • Helium requires high pressure containers • Helium is practically “non -renewable ” o We owe it to future generations to save Helium We Have Alternatives…Let’s use them
U.S. Navy efforts to use H2: H2 UAS New World Record: 48 Hours! H2 Fuel Vehicles at Joint Base Hickam, HI
H2 accepted in other countries • Rest of the world has embraced Hydrogen o They have never had access to vast Helium supplies • Established effective & safe distribution, use o Pipelines o Operating Procedures o Cultural Awareness • H2 Routinely used as Lift Gas • For Unmanned -and- Manned Flight • But: Not for Military applications • We can learn from their experience o Especially for tethered applications o NOAA and NWS already using H2
H2 Resources • http://www.undeerc.org/NCHT • http://www.hysafe.org
H2 Gas Generation • Developed for a “ tactical “ application o Need to quickly generate useful volumes of H2 • “Solid State” • Scale-able • Portable
Hot Air / Steam • FESTO / Germany • Insulated Fabric / Envelope • Propane Energy Source • Proved Viable Alternative • Potential for Hybrid Design
Nexutech “ Aeronexus ” • Aerostat system to “Connect and Protect ™ ” o Cell Site o Camera / Analytics o Advertising • Utilize best-of-breed tether system: o Power-up-the Line o Capillary gas replenishment explorations • Hot air / hybrid o Goal: 100% propane power for system
Closing… • Tethered systems replace / augment UAS o Especially while NAS issues are unresolved • Opportunities exist to embrace innovation • Be good stewards of natural resources • Learn from the success of others
Thanks to: • BOSH Technologies • Blimpworks • Anasphere • NRL • Contact: jaywillmott@nexutech.com
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