Propulsion System
North American Aerospace optimizes among a wide range of available propulsion systems, which allows the best exploitation of the airframe characteristics as well as generating proper thrust in order to comply with all the assumed requirements. The goal is to increase performance in fuel efficiency, emissions, noise, landing distance and maneuverability. Our drone groundwork is based on the premise that only electric motor based propulsion system is not suitable; the microturbine engine is optimal for hybrid-electric propulsion system; and, the parallel-hybrid propulsion system is preferable to the series-hybrid.
Acoustics
Drone noise mainly is created with three sources: the propulsion system converting the energy of the fuel into the thrust; the flow of the air around the fuselage; and, the vibration of the structure with the forces, including the propeller(s). Electrical powered drones operate more efficiently, and create less vibration and noise compared to a drone which use combustion gas type propulsion systems especially at high altitude operations. Significantly, North American Aerospace’s patented propeller design is the solution to propeller noise. Our propeller design is race proven on the #62 Phantom biplane at the Reno Air Races. The human ear cannot discern propeller sound on the Phantom. Listen for yourself as the Phantom laps the race field at the 2018 Gold Championship Biplane win in the Vimeo video below.
Autonomy
Fiber optics to handle high-bandwidth applications, flight messengers to monitor maintenance needs, and aviation analytics are our evolving technologies. Our focus has shifted from health and usage monitoring (HUMS) through telemetry to where we use Artificial Intelligence (AI) to accurately monitor the health of any engine on-board in real time and autonomously address future faults long before any other form of health monitoring. AI is actually a multi-layered concept, ranging from machine learning, to adaptive reasoning, cognitive computing, and to full artificial intelligence. The first has been in use for several years, the second more recently, the third is still under development, and the final step has some way to go.
Connectivity
Connectivity has traditionally been thought of as direct, point-to-point communication between a ground station/operator and the vehicle itself. We use connectivity in the design considerations of our patented design which allows the user to replace the propulsion system in under thirty minutes. North American Aerospace uses its engine mount/isolator design and our partner’s quick disconnect fittings for all fluid and electrical connections to achieve the design goal.
Efficiency
The functional limitations of batteries require the integration of more efficient airframes, the more efficient North American Aerospace propeller and more efficient and lighter internal combustion engines. A hybrid-electric drivetrain can lead to substantial improvements in fuel efficiency of a given aircraft configuration, though these gains depend strongly on the coupled variations in the degree of drivetrain electrification and the required mission range. Both of these factors influence the weight allocation of battery and fuel systems, as well as the weight scaling imposed by internal combustion engine and electrical motor components. In general, to obtain the greatest fuel efficiency we use a hybrid architecture that has as much electrification in the drivetrain as is permissible within a given range requirement.
Standalone
The North American Aerospace propulsion system is modular and agnostic to the battery chemistry, allowing the architecture to scale to the needs of the user. The REx turbo charged internal combustion engine and microturbine, both in development, are able to harness a lot of horsepower in a small package. So, like all our components, the REx engines, the quick disconnect architecture, the propeller, and the software are scalable and stand alone for use in applications other than the North American Aerospace propulsion system.
