I'm not knocking what they are doing, at all. Really nice progress.
But the title is pretty misleading. This article is about an attachment nozzle. Unless I missed it, it is nothing resembling a "new engine design."
But the title is pretty misleading. This article is about an attachment nozzle. Unless I missed it, it is nothing resembling a "new engine design."
They are starting with an attachment as it means it can easily be retrofitted to existing planes and tested. If it works there is a good chance it will be the default design on a new generation of engines.
I don’t think this is misleading.
Except that in the case of a jet engine, this is more like the exhaust, transmission, and differential.
Look into tech like thrust vectoring.
It's WAY, WAY more than a muffler
I'm perfectly familiar with typical ICE and the design of jet engines. Exhaust is no less important in ICE. If you block it, the engine doesn't run.
Jet engines use exhaust as propulsion, so it just moves the mechanism from inside to out, in a way.
A muffler is a device that baffles air to quiet it. That's -exactly- what this device does. You can argue, rightly, that more is at stake and more considerations must be made here. But it's still, by definition, a muffler.
Exhaust systems can be tuned, as in using wave propagation to scavenge the exhaust gasses out of the combustion chamber much more efficiently. Intake manifolds are tuned for the opposite effect. The dyno tests on my Dodge V8 showed adding a 3/4" spacer between the carb and the manifold added 40 HP at the peak power rpm.
Also on exhaust side. Too big of exhaust, such as 'open exhaust', is worse in most cases than restrictive. Apparently a restrictive exhaust provides both accounted for backpressure, and at times a bit of a vacuum effect.
Anymore, I just trust the makers know what they are doing and go with it. But 40 years ago, very different story. My 2019 Colorado would outrun my old 66 mustang, both in stock forms.
Was this measuring at the flywheel or at the wheels? I'm genuinely interested, it's been a long time since I've had grease under my fingernails.
The guy doing it remarked that it really made a dramatic difference, it seems the original parts configuration was a pessimizer. I'm not too surprised, because the engine was heavily modified and so would exhibit very different flow characteristics from the stock configuration.
I don't remember the RPMs. It's a bored, stroked, and rollered 340 engine, and peaked at just under 400 hp. The dyno guy normally worked with drag engines, and told me I was an idiot because I had the stock heads modified rather than getting aftermarket performance heads, a mistake that likely cost me another 40 hp.
The engine was built as a sleeper, so the only way you can tell there's some monkey business going on is the oversize aluminum radiator, but nobody notices that :-) But they notice when I start it.
The average person can’t even draw bikes that work[1].
[1] https://twistedsifter.com/2016/04/artist-asks-people-to-draw...
For example when a 737 has a broken light, then it is not in compliance with the approved type design and any aircraft in such a state is legally not airworthy.
Fortunately we have provisions in airworthiness to defer rectifications of unserviceabilities that have no/marginal effect on actual airworthiness, but the point stands. The light is part of the aircraft's design.
If you change a light to a new kind of light, then you're embodying a Design Change which is a Big Deal (tm) even though it seems minor, and that piddly little light will go through the same design approval process as, say, a new wing. Less structural analysis will be conducted (obviously) but it's still the same process.
In aerospace, changing the nozzle on an engine changes the design of the engine. "Design" in that context is an industry term and it doesn't have the same nuance as in other contexts.
"JET PILOT tries 3 different attachment nozzles from Wish"
This could make more sense for jetliners, especially for late night take-offs.
Granted, this would help people who live next to active airbases, but noise form commercial traffic is a bigger issue as more people are exposed to it and are usually closer to dense cities.
Growing up in the DC area in the post-9/11 era fighter jets were quite a common experience. Except for 9/11 every other time there was really nothing to worry about. Obviously this might be different if you live in say Syria or Palestine.
And if you have fighter jets buzzing by, the least of your problems is noise.
More importantly, as the article mentions it would also help protect the hearing of sailors, airmen, and marines that help operate those airframes.
A major winner would be the communities near airbases. Hornets, in particular, are quite loud.
https://www.stripes.com/branches/navy/2021-08-19/naval-air-s...
You only hear the jet after it passes you.
The ground crews at the target had to be very vigilant.
Are they going to report anything they hear from any source along the whole border? Imagine the control center having to match every hearing with every domestic and recognized flight
Further down on my list would be a bunch of nations bordering those three, a handful of African nations, and two or three south American nations.
I'm not sure if Taiwan should be on the list, as the People's Army does not currently have operational stealth aircraft.