Comment on Blue Origin has hot fired its BE-4 rocket engine for the first timeComments−faitswulff8yA few frames of the video caught my eye: https://screenshots.firefox.com/eOm06NUSg0CSkb1a/arstechnica...It looks like there's some sort of harmonic wave in the blast. Does anyone have any insights on why the design would result in that?−trothamel8yI believe those are Mach/Shock diamonds, which are common in rocket engine exhaust. It wouldn't surprise me if the propellant and the time of the test made them more visible.https://en.wikipedia.org/wiki/Shock_diamond−tim3338yAs also seen on page 2 of "Ignition" with page 3 showing some other interesting rocket effects. http://library.sciencemadness.org/library/books/ignition.pdf−fkfk8yThey are called shock diamonds and are caused by standing shock waves in the exhaust plume: https://en.wikipedia.org/wiki/Shock_diamond−paulyg8yIts supersonic shock waves. https://en.m.wikipedia.org/wiki/Shock_diamond
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A few frames of the video caught my eye: https://screenshots.firefox.com/eOm06NUSg0CSkb1a/arstechnica...
It looks like there's some sort of harmonic wave in the blast. Does anyone have any insights on why the design would result in that?
I believe those are Mach/Shock diamonds, which are common in rocket engine exhaust. It wouldn't surprise me if the propellant and the time of the test made them more visible.
https://en.wikipedia.org/wiki/Shock_diamond
As also seen on page 2 of "Ignition" with page 3 showing some other interesting rocket effects. http://library.sciencemadness.org/library/books/ignition.pdf
They are called shock diamonds and are caused by standing shock waves in the exhaust plume: https://en.wikipedia.org/wiki/Shock_diamond
Its supersonic shock waves. https://en.m.wikipedia.org/wiki/Shock_diamond