Baby Boom demonstrator unveiled

a reply to: Blackfinger

Both demonstrators are on track to fly by year end.

I'm Confused easy to do sometimes.

I thought the sound barrier was a limit that when passed it's quiet again. Not being able to cross it over land I understand but then crossing land after breaking it wouldn't be any different than a normal flight.

It's not a constant rolling wave is it??

Confused.

a reply to: mikell

Yes it is. The aircraft is constantly breaking the sound barrier as it moves so there's a continuous boom (actually a double boom) as it flies. The shape of the aircraft determines the pressure of the shockwave at ground level.

The barrier then is like a wave that follows the craft??

a reply to: mikell

Yes. It's the same with an aircraft in normal flight. Only the air immediately around the aircraft is affected. As the aircraft moves forward, it has to continue to push the air around it aside.

a reply to: mikell

Think of it like a boat's wake.

Quiet-booming aircraft are like building a wakeless boat. It's pretty easy when you're going small, but gets much, much harder as you get bigger, simply because larger aircraft displace more air as they fly just as a larger boat displaces more water.

That's why the shapes you see for large quiet-booming aircraft concepts are so weird and stiletto like (just like the hulls of the low-wake commuter ferries on the Thames in London), because it's all about making that volume move through the air while disturbing it as little as possible.

Quiet-booming aircraft also have the difficulty of needing to shape their wakes, er, shockwaves in three dimensions so that as much of the energy generated by their movement through the air at supersonic speeds is directed away from the ground rather than towards it. Naval architects have it easy since they only have to think in two dimensions.

And for 50 years or so I was thinking more like a gunshot because that what we hear.

Thanks

a reply to: mikell

Size and shape. A bullet is small and designed for a very small footprint. If you were to scale it up, you'd hear multiple booms from it.

I remember the shuttle having 2 booms I thought entering supersonic then exiting would cause it.

Thanks

a reply to: mikell

With each sonic boom, there are actually two booms. One at the nose, as the aircraft goes supersonic, and one at the tail, as the "bubble" created by the shape of the aircraft closes behind it. With a normal aircraft the shape prevents you from hearing the second boom clearly. With the shuttle, it was big enough at the aft section that you could clearly hear both booms as it went over.

Pictures were released on social media today of wind tunnel models of the XB-1.

a reply to: Zaphod58

It's remarkably conventional looking, and reminds me a ton of the old Gulfstream/Sukhoi designs. It'll be interesting to see how they manage to keep such a decidedly old-school supersonic design quiet.

a reply to: Barnalby

Boom is more conventional, and will be a regular small scale SST.

The demonstrators J85-15 engines have been run at 95% power at the Air Force Academy test cell on their first run.

a reply to: Zaphod58

I was tracking a Chinese Gulfstream from Fairbanks to BWI the other day. I guess the high-end transpacific bizjet market has matured enough for Boom to be giving it a shot. Conventional supersonics seems like overkill for a transatlantic crossing and an utter nonstarter for anything between the Middle East and East Asia or Europe, but I could see it making sense for Chinese plutocrats who want to slash their 12-hour trips beteween China and the West Coast. I honestly hope it succeeds, if only because GA desperately needs to get more exciting.

Some more bucks for Boom:www.ainonline.com...

At least first flight for XB-1 seems assured.

According to the schedule released by Boom, the XB-1 is set to roll out by the end of this year.

Ooohhh not vaporware finally Cant wait to see the airframe on the Tarmac!!!!

Close for a nice rendering