Jacob Leachman, an associate professor at Washington State University’s School of Mechanical and Materials Engineering, has received a $1.8m grant from the US Army to demonstrate a liquid hydrogen-powered unmanned aerial vehicle (UAV) and refuelling system.
The $7.2m total grant includes researchers from Mississippi State University (MSU), Institution Inc., and Navmar Applied Sciences Corporation.
Insitu, a subsidiary of Boeing, will provide its ScanEagle3® UAV, equipped with a fuel cell-powered electric engine. MSU will measure the performance characteristics of the drone.
“Our goal is to make hydrogen refuelling of military vehicles more convenient and reliable than conventional hydrocarbon fuels,” said Leachman, head of the HYdrogn Properties for Energy Research (HYPER) laboratory at WSU.
To convert hydrogen into liquid, it must be cooled to a very low temperature. The HYPER lab specialises in working with hydrogen at low temperatures.
Liquid hydrogen uses less space than hydrogen in its gaseous state, meaning more of it can be packed into a UAV providing a longer flight time. The liquid hydrogen system will operate at less than 30 psi pressure, making the storage tank lighter.
To create the lightweight tank, Leachman is working with Protium Innovations and plans to use light-weight polymers instead of metal for the tank which will save weight, reduce filling time, and increase flight time.
“Every pound you can reduce in the tank’s weight means an extra pound of fuel the UAV can carry to stay in the air longer” said Ian Richardson, Co-Founder of Protium.
“WSU is one of the few places in the country where we can test polymers at very low temperatures.”
According to Leachman, advances in cryogenic refrigeration technology and electrolysis have made it possible to create a compact hydrogen refuelling system.
“We want to make the system small enough to be conveniently transportable by aircraft and to be useful in a military theatre of operations.”
Test flights for the liquid hydrogen-powered UAV will begin this winter. The grant provides funds to build an outdoor facility for testing liquid hydrogen transfers. The facility will be built on the WSU Pullman campus.