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Iss ya boi Ernst again..."I've got a fever and the only prescription is more shockwaves." 🔊🌊
Ernst Mach retweeted
Polygon patterns of convection form when liquid nitrogen is poured into a warm beaker. This work, by Alexis Duchesne et al at TU Denmark, was a winner of the 2018 #GalleryOfFluidMotion. The full video is at go.aps.org/3Q5a4oR #FluidDynamics #FBF #Physics #Chaos
Ernst Mach retweeted
This is very cool! You just know I am going to show this on opening day in my grad fluids class 2.25 this Fall! 🌊 ✈️ 🚀 – at Acton, MA
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Ernst Mach retweeted
Our latest prediction for #CZ5B rocket body reentry is:
🚀30 Jul 2022 17:24 UTC ± 1 hour
Reentry will be along one of the ground tracks shown here. It is still too early to determine a meaningful debris footprint. Follow this page for updates: aerospace.org/reentries/cz-5…
Ernst Mach retweeted
Or reach out to the authors for a preprint:
researchgate.net/publication…
Ernst Mach retweeted
Alas, link generate by website for the paper doesn't appear to work. Better link—as always—is DOI:
doi.org/10.1017/jfm.2022.581
Ernst Mach retweeted
20 years ago, I started to work with my students on the problem of detonations propagating into inhomogeneous media. This new paper by Aslan Kasimov in @JFluidMech reveals a richer dynamics than we ever imagined:
Arnold tongues and devil's staircases bit.ly/3cSjhCP
👀
Deep throttling, fine-tuned, and rapid response engines are key to reusability. #BE4 steadily ran for over 256 seconds in this transient power level demo test across varying mixture ratios and power levels between 45% and 100%. The exhaust plume length adjusts with power level.
Ernst Mach retweeted
#DailyMechanician Gury Vasilievich Kolosov headed the theoretical mechanics dept. at St. Petersburg Univ. in early 20th century & was an early proponent of utilizing complex potential. A material constant used for brevity of plane elasticity solution is fittingly named after him.
Ernst Mach retweeted
THIS IS NOT A SONIC BOOM
Okay folks, it’s been long enough. Time to finally address the biggest point of confusion on #AvGeek twitter: what exactly is going on with vapor cones?
Let’s just say much of what you’ve read is (probably) wrong. Wonder no more: a thread... 1/n
Ernst Mach retweeted
Replying to @PhysRevFluids
@PhysRevFluids is this an lonely APS-DFD duck????
RUBBER DUCKY ALERT🐤🐤🐤🐤🐤🐤🐤🐤: Stuart Laurence's group at @UofMaryland produces some of the highest quality #schlieren data I have seen. He might be taking requests. Email at [email protected]. Funded in part by @NSF.
Ernst Mach retweeted
Replying to @DrChrisCombs @Bloodhound_LSR
The model size they were using is very small, so the relative size of the boundary layer is very large compared to the model size. But I like this solution because it's like Method of Images in real life. Supersonic ground effect is indeed a complex problem!!
Poor ducky...but love to see #shocks
RUBBER DUCKY ALERT🐤🐤🐤🐤🐤🐤🐤🐤: Stuart Laurence's group at @UofMaryland produces some of the highest quality #schlieren data I have seen. He might be taking requests. Email at [email protected]. Funded in part by @NSF.
Ernst Mach retweeted
To the U.S. `I have a PhD’ in high-speed aerodynamics community, underestimating the capability of foreign powers is foolish.
Ernst Mach retweeted
Equations are destroying our youth...keep them out of your powerpoint presentations
Ernie here: Take it from me high Mach is nothing to fuck around with.
Replying to @AffectDelta
The appearance of these new instabilities are only possible at high Mach number (M\gtrsim 4 to 5) and they are the dominant precursors to the transition-to-turbulence process in quiet [even noisy] wind tunnels.
Ernst Mach retweeted
Huh??? “The challenges of hypersonic flight aren’t different from those of lower supersonic flight, they’re just way worse.”
Hypersonic BLs ARE sensitive to different disturbances compared to their subsonic and moderate-supersonic counterparts.
annualreviews.org/doi/abs/10…
Hypersonic is an often misunderstood word, and for good reason. Achieving hypersonic speeds is tough, but it's not all that special... and it certainly isn't new.
sandboxx.us/blog/its-a-myth-…





















