Hermeus is testing its proprietary precooler technology with the Pratt & Whitney F100 engine. This video shows some of the best camera angles from testing.
What's a precooler and why are they testing it?
The Hermeus precooler increases the max speed of the turbine engine by lowering the temperature of incoming air. This is the first major propulsion milestone for Hermeus' next aircraft, the Quarterhorse Mk 2, which will utilize this engine configuration and fly at supersonic speeds. The precooler is part of the larger turbine-based combined cycle (TBCC) engine.
The TBCC engine, named Chimera, is a full-range, air-breathing hypersonic engine combining a turbine with a ramjet. At low speeds, Chimera operates in turbine mode with the F100 engine, while at higher speeds the engine transitions to ramjet mode. The precooler helps bridge the gap between these two modes of operations by increasing the performance of the turbine.