Hermeus

Hermeus is a developer of hypersonic aircraft for commercial travel and military aviation. The company's platform is developing aircraft with the goal of massively reduced flight times and increased safety for long haul and business class air travel, enabling businesses to operate with minimal changes to current aviation infrastructure. Hermeus wants to develop vehicles that can fly in excess of Mach 5, over 3,000 miles per hour (4,800 km/h). At these speeds, a flight from New York to London is reduced from 7 hours to 90 minutes. The company was founded in 2018 and headquartered in Atlanta, Georgia.

In early 2020, Hermeus was able to demonstrate a subscale engine prototype and the core design of its technology perform as intended. The demonstration was able to simulate flight at Mach 3.3 at 65,000 feet in a windtunnel simulation. The prototype was built using an off-the-shelf turbojet capable of operation at 533 knots (988 km/h) at a maximum altitude of 25,000 feet.

With it's October 2020 funding, the company is looking to expand it's Atlanta-based test facility to include in-house manufacturing and continue to design their debut aircraft.

To achieve their results, Hermeus is focused on using existing technology and materials rather than finding or founding any new technologies or materials. And to that end, the company developed a combined cycle turbofan design that fuses a normal turbofan engine and a ramjet into a single engine.

Hermeus's combined cycle engine during testing.

This combines the turbofan engines linear air movement through the engine with a ramjet engine, where the ramjet engine is designed to ram greater amounts of air into the engine using the forward sped of the aircraft and achieve greater thrust. The usual complexity of ramjet engines is that they do not work at subsonic speeds and are envisioned as separate engines or as a rocket booster. The combined cycle engine seeks to solve this problem through a switching between one engine type for take-off and landing, and another for reaching hypersonic speeds.

Hermeus has also worked towards solving the thermal problems of supersonic speed, namely the increase of temperature in the air passing through the engine which decreases the ramjet's efficiency. The company says they have solved this problem using a pre-cooler to chill incoming air before it enters the combustion chamber.

In August 2020, the United States Air Force awarded Hermeus a $1.5 million contract to asses modifying the company's in-development Mach 5 jet into an aircraft for the Presidential and Executive Airlift fleet.

Hermeus Air Force One Concept