Johnny Armstrong, the Hypersonics Combined Test Force Chief Engineer for Air Force, until his retirement in 2012, passed away just last week. He worked in hypersonics from the X-15 to the X-51 Waverider.<p><a href="https://www.edwards.af.mil/News/Article/1922993/team-edwards-loses-one-of-its-own-as-hypersonics-pioneer-johnny-g-armstrong-dies/" rel="nofollow">https://www.edwards.af.mil/News/Article/1922993/team-edwards...</a><p><a href="https://vimeo.com/37453969" rel="nofollow">https://vimeo.com/37453969</a>
This is a pretty neat technical achievement. One of the things that has made it possible has been the ability to much better CFD simulations of the whole system. Rather than test/tail iterate cycle, they can get to a working system that can be refined in a shorter period of time.<p>That said, its hard to beat the SABER engine's use of liquid hydrogen to cool the air coming into the engine and just achieving better thrust. I still find that concept mind blowing.
> The Air Force recently broke the record for the highest thrust producing air-breathing hypersonic engine the service has ever tested in its history, at least that we know about.<p>Nuclear scramjets achieved 3 times this thrust "record" under similar test conditions more than half a century ago.
Here's a picture of the test apparatus. This barely resembles a typical wind tunnel. Anyone who know these things care to provide a illustrated guide to thing?<p><a href="https://media.defense.gov/2019/Aug/05/2002166487/-1/-1/0/190220-F-IL571-080.JPG" rel="nofollow">https://media.defense.gov/2019/Aug/05/2002166487/-1/-1/0/190...</a>
I remember scramjets in Popular Mechanics 30 years ago, but nothing seemed to materialize.<p>Off-topic to scramjets but potentially military-related: Making a <i>big</i> stretch by assuming the "white Tic-Tac" isn't an elaborate hoax to get adversaries to overspend on propulsion technologies and/or troll the public, what type of propulsion could allow it to accelerate so quickly? Casimir effect thruster?
Is the SR-71 constrained by its engine or airframe? I know I’ve read that if the plane went any faster <i>something</i> would start melting and the plane would be lost but I don’t recall if it was the airframe or the engine.