Scrutable

Anyone heard of aerospikes ?
https://everydayastronaut.com/aerospikes/

It found the Wikipedia article helped
https://en.wikipedia.org/wiki/Aerospike_engine.

I have heard the term before, maybe thirty years ago, before the WWW certainly, and didn't know about the technical details, so thanks for that link.

I've heard of them many times. Mostly in popular magazines just after an article on nuclear fusion power plants...

I’ve heard of them but was never quite sure how they worked and what was purportedly cool about them. Thanks for the link.

Heard about them when I first played Kerbal Space Program (which I found out yesterday when giving my email inbox a decades overdue sortout, was now almost 10 years ago ).

Very cool tech, though I share Tim Dodd's feelings that spikes are not likely to overtake bells any time soon because bells are broadly good enough and the investment has already been made to get them highly mature, so diminising returns in following that same path with a different technology with big issues yet to be solved. Spikes would be awesome for overcoming the nozzle pressure optimisation issues inherent with Single Stage to Orbit vehicles, but those are deeply flawed on the mass efficiency front too so I don't think we'll be seeing them any time soon*.

When I saw the thread title I thought this was about people saying that rockets are shaped how they are as phallic symbols because men design them, and so they should be changed because equality. I once set next to a person on a plane who thought that, we had a fun conversation but since I'm a bloke they were not minded to be convinced by anything I said on this particular topic.

*The only exception I can think of would be Skylon, which is still slowly progressing its technology, but gets over the sea level pressure with a jet engine and converts to rocket when the ambient air pressure is already low enough that a vacuum optimised nozzle isn't such a big issue. Additionally the external exhaust expansion of an aerospike may complicate placing their jet hardware in this architecture in ways that a bell avoids.

dyqik wrote: ↑

Sun Dec 08, 2019 1:12 pm

I've heard of them many times. Mostly in popular magazines just after an article on nuclear fusion power plants...

Actually, I think I'm thinking of scramjets here.

I noticed that garden hoses often have nozzles that look like the pictures of aerospikes - there is a curved bit leading to a flat plate, and as you adjust the plate in and out the jet gets wider or narrower. Same mechanism?