UAV Turbines takes microturbine technology to a new level with turboprop propulsion for Group 3+ systems for Unmanned Aerial Vehicles…now with turbogenerators to extend the range of electrically powered aircraft and for multiple ground power applications.
During this awkward COVID limitation on activity UAVT is actively working on integration of its recuperator technology with a prototype of its Monarch 5R micro-turboprop aircraft propulsion system. Senior VP Fred Frigerio explains that “An engine burns fuel, creating heat that causes expansion of the air, powering pistons in reciprocating engines or turbines, as in our engines. The expansion of the air doesn’t dissipate all of the heat, and what remains is usually just exhausted into the atmosphere. A “recuperator” saves much of that otherwise wasted heat and feeds it back into the engine, potentially saving a significant percentage of fuel, increasing the flight time of an aircraft, for example.” There are tradeoffs. The recuperator is hardware, weighs something, costs something, takes space, and consumes some energy. You have to balance the advantages against the costs. In an aircraft especially, size and weight are critically important. Commercially available recuperators don’t serve our needs, so UAVT has developed a proprietary new system and tested it for several years. Now we are adapting it to the Monarch 5 engine, which can be configured to operate in the 25 to 40 kW range. It’s very productive activity during what could be COVID down-time.
Experimenting with a wide variety of fuels, UAVT is reporting operation of the Monarch 5 engine on compressed natural gas (CNG)
See release on the NEWS page.
UAVT is demonstrating its micro-turbogenerator technology
in an easily portable prototype for ground-power applications.
See video below
UAVT is now demonstrating its Monarch microturbine technology
configured for Hybrid Range Extension (HREX) in aerial vehicles.
See video below
In August 2019, UAVT demonstrated its Monarch 5 turboprop propulsion system
powering a NAVMAR TigerShark Group 3 UAV.
See video below
The technical definition of heavy fuel involves flash points, viscosity and a number of other characteristics such as more or less sulfur content, higher or lower freezing points, etc. Broadly, in our context the term refers to fuels that do not evaporate quickly at low temperatures, and don’t ignite easily, unlike gasoline. Kerosene, diesel oil, and jet fuels are considered heavy fuels. They are far safer to handle and transport than aviation gas, and are much more readily available. UAVT’s Monarch gas turbine engines can burn almost any heavy fuel, including synthetics.
Pressed to say quickly if our engines can operate on Brazilian Ethanol, one of our too-busy engineers did a quick calculation, and handed over this note before rushing off: “Assuming an LHV of 22.35 GJ/m^3 for Brazilian Ethanol gives about 34 liters. It’s a VERY rough estimate.”
“If ‘real people’ are limited to hobbyists and freelance photographers using GoPros,” says VP of Engineering Fred Frigerio, these “then yes, the hi-tech systems are probably out of their reach.” These very light, reliable microturbines are designed for at least 2000 hours of operation between overhauls, and intended for sustained use in critical applications on which lives may depend, Every application is different, so the engines must be integrated into the overall design of the aircraft. This is not a one-size-fits-all situation, and until production of a particular system reaches substantial volume, we can’t calculate an off-the-shelf price. Sorry.
UAVT is developing standalone generators producing power at different levels, that can be built in significant numbers, reducing cost, but again, where are you going to use it…in a weather station at sea level in the arctic?…in the hot, high desert?… for steadily operating lights and electronic equipment?… powering on/off motors (refrigeration systems, for example) that drain a lot of power from the system in startup surges?
This isn’t the sort of equipment you’d buy from a big box hardware store to get you through a few days of home power outage after a storm.
Batteries are too heavy. Pound for pound, liquid fuel carries about 50 times more energy than batteries. Turbo-electric hybrids are a near term solution.
Safety is a major issue. Cargo drones must achieve FAA approval for use in civilian airspace.
The public does not tolerate in urban neighborhoods the racket produced by current avgas and diesel-powered aircraft engines. Hybrid cargo drones transporting hundreds of pounds will be able to take off and land with quiet electrical power (only prop noise, almost no engine noise) and use turbogenerators during flight. Until the Power Density, Safety, and Noise issues are resolved, only package delivery drones will be practical.
It isn’t. That’s an easy-to-modify system we’ve been using as a development platform, bigger than necessary for the ~3kW generator inside. We’ve actually been able to operate that on the exhibition floor at a convention without upsetting our neighbors. The technical team plans to package a 25kW turbogenerator weighing less than 50 pounds in a case convenient for handling by one man.
Just terminology in our usage; until recent years there had been no need to classify a wide range of UAVs into groups by power, size, application, etc. Different conventions for classification developed quickly, and are somewhat different in Europe and the U.S., for example. Civilian industry in the U.S. tends to refer to Classes, the Military to Groups.
Redefining Portable Power Use
UAVT is developing a family of Micro-Turbogenerator Systems (MTS) for on-demand electrical power ranging from 3kW to 40kW. They are small, quiet, use a variety of available fuels, and can be moved without need for forklifts and trucks.
These new systems seamlessly adjust to situational changes, providing power where it’s needed with little to no downtime. They address the critically important needs of rescue teams and military units operating in adverse weather, rough terrain, and hostile environments, with limited logistical support.
See the MTS video.
Monarch Hybrid Range Extender (HREX)
Microturbine powered generator technology extends the range of electrically powered medium-sized unmanned aircraft (UAVs).
UAVT set up a demonstration in its laboratory test cell using the same Monarch 5 turboprop engine that recently powered a Group 3 TigerShark aircraft. Converted to a turboshaft engine, it powers an off-the-shelf generator. The electrical output of the generator is used to power an electrical motor driving a propeller, as it would in an electrical propulsion airplane and charge a battery for bursts of power.
See the video of the demonstration.
The Monarch 5 Flies
The Monarch 5 turboprop system developed by UAV Turbines, Inc. flew for the first time at Griffiss Airport in Rome, New York in August 2019. The Monarch 5 powered a TigerShark aircraft produced by Navmar Applied Sciences Corporation.
Two demonstration flights were executed as planned.
Using Jet A fuel, the aircraft was much quieter and provided a smoother flight with the Monarch 5 when compared with existing inferior internal combustion engine systems; this according to experienced TigerShark operators.
These flights mark the start of a new era
of highly reliable, quiet, heavy-fuel burning propulsion systems for small aircraft.
See the video report of the event.