HN Reader

From the article:

"In contrast to a traditional rocket engine, in which a highly pressurized propellant and an oxidizer are injected into a combustion chamber where they burn and produce an energetic exhaust plume, a rotating detonation engine is different in that a wave of detonation travels around a circular channel. This is sustained by the injection of fuel and oxidizer and produces a shockwave that travels outward at supersonic speed."

Nope ... on my way to do web searches to try to figure out what this means.

First stop: https://en.wikipedia.org/wiki/Rotating_detonation_engine

"A rotating detonation engine (RDE) uses a form of pressure gain combustion, where one or more detonations continuously travel around an annular channel. ... In detonative combustion, the flame front expands at supersonic speed. It is theoretically up to 25% more efficient than conventional deflagrative combustion ... Disadvantages include instability and noise."

No images, no animations.

OK ... bookmarked, and I'll chase the references later.

Edit: OK, here's the best reference I've found so far:

https://www.sandboxx.us/news/what-is-a-rotating-detonation-e...

Now back to work.

https://youtu.be/QR6iFVj_xHw?feature=shared Here's a good webinar with some visualization if you're interested in learning more.

This is one of the few hypersonic technologies which could actually be enabling. This is because detonation speeds things up and increases range compared to deflagration (burning) without necessarily needing air-breathing added. This means the craft can remain a simple tapered cone traditional rocket and avoid shockwave imgingement sites on the craft air intakes and the thermal load of that that is so far infeasible to maintain for more than a minute or two.

Still trying to wrap my head around this. Doesn’t this cause insane stresses with basically all explosions being off axis? Or are there multiple sets of explosions moving at same the on opposites sides?

>Sassie Duggleby and her husband, Andrew Duggleby, founded Venus Aerospace nearly five years ago with the long-term goal of developing powerful rotating detonation engines and building a hypersonic aircraft that could carry perhaps a dozen passengers and travel at astonishingly fast speeds worldwide.

As an engineering project it sounds really cool, but is the application really commercial travel? I would have thought the military would be far more interested and much better funded.

JAXA flew one in 2021, to give a sense of developmental pace.

2 hours? What's the point? It could be 0 minutes with a 0% explosion rate and the total travel time would probably be longer.

Press release videos - https://drive.google.com/drive/folders/194_lxE-vy_ha7-5V_wFj...

Their YouTube is insanely technical, I think, lots of videos with big equations anyway - https://www.youtube.com/@venusaerospace/videos

How do you restart after flameout?

> hypersonic

This is a meaningless term. There's just varying degrees supersonic. "hyper" implies a completely different thing.

EDIT: apparently the military has bastardized the term