Hermeus, a startup developing hypersonic aircraft, demonstrated turbojet-to-ramjet transition within its Chimera engine:
Chimera is a turbine-based combined cycle engine (TBCC) — which basically means it’s a hybrid between a turbojet and a ramjet. The ability to switch between these two modes allows Hermeus’ first aircraft, Quarterhorse, to take off from a regular runway and then accelerate up to high-Mach speeds.
The cost and speed at which the Hermeus team achieved this milestone is notable. Hermeus designed, built, and tested Chimera in 21 months for $18 million.
“This achievement is a major technical milestone for Hermeus,” said CEO AJ Piplica. “But more than that, it’s a proof point that demonstrates how our small team can rapidly design, build, and test hardware with budgets significantly smaller than industry peers.”
The testing took place at the Notre Dame Turbomachinery Laboratory which provides heated air to simulate high-Mach temperatures and pressures.
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At low speeds Chimera is in turbojet mode — just like any jet aircraft. But as the temperature and the speed of the incoming air increase, turbojets hit their performance limit. This happens at around Mach 2.
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At around Mach 3, Chimera begins to bypass the incoming air around the turbojet and the ramjet takes over completely.
A ramjet is a simple propulsion system which “rams” the incoming high-pressure air to create compression. Fuel is mixed with this compressed air and ignited for thrust. Ramjets are optimal between Mach 3 and Mach 5.
And the US, after a decade of work, still can’t do this? I am going to label these claims BS.
If you’d bothered to read the linked article you would have noticed they are doing this in a partnership with the US (Air Force/NASA). And the test was in a fixed ground based installation, presumably than an actual flying platform.
To be honest, normally I would be in the peanut gallery throwing with the best of them. But compare what SpaceX is doing vs NASA SLS, and my reaction is slowly shifting to “cool, show me more of that”.
This is all very impressive—and I mean that sincerely—but the question that everyone is asking is whether Hermeus Corporation, a State of Delaware corporation recipient of over one hundred million dollars from Sam Altman of OpenAI, Founder’s Fund of Peter Thiel, and In-Q-Tel of CIA (but I repeat myself), has the proper representation of Black Africans, Indians, Indians, and Colored Persons (BAIICP) on payroll generally and especially in positions of command, as determined by the good corporate proctors of the United States Department of Justice. As a patriotic American and steadfast defender of the Constitution I have no doubt whatsoever that the United States Air Force and National Aeronautics and Space Administration are in fact far superior by all the most important metrics. After all, he who seeks equity must do equity.
Kidding aside, I have high hopes for the future of airborne craft.
The press release was going so well right up to the last sentence: “Hypersonic aircraft have the potential to create trillions of dollars of new global economic growth per year, unlocking significant resources that can be utilized to solve the world’s greatest problems.”
Sure it could help solve the world’s greatest problems: hypersonic drones dropping belated birthday presents down the chimneys of all the spiritual crabs trying to keep humans from climbing out of the bucket of our earthly imprisonment.