Better than Concorde?

[Adam the Akrodude]

This might cheer up TOR if one day it gets the nod - and it's a Boeing!

http://aeronauticsonline.com/boeing-reveals-concept-for-hypersonic-passenger-jet/

[Ansett A330]

Looks like someone in the Graphics Department took an image of the Sonic Cruiser and elongated it!

[Adam the Akrodude]

The very pointy nose is interesting as this usually is a no no from my reading of hypersonic design - X-15, Shuttle, lifting body designs, X-37, etc have a rounded nose.

[BradG]

Why is a pointy nose a no no? The Blackbird would seem an exception there?

[scotty100368]

Why is a pointy nose a no no? The Blackbird would seem an exception there?

https://aviation.stackexchange.com/ques ... ose-better

Scott.

[Adam the Akrodude]

Why is a pointy nose a no no? The Blackbird would seem an exception there?

Pointy nose great for supersonic flow (Mach 1-3), but not hypersonic (Mach 4 up) flow in regards heating. Blunt nose is draggier, but that's not an issue with vehicles like the Shuttle, X-37, X-15 - stuff that needs lots of drag to slow down on re-entry. Looking at this response below to this very question below answered my question. Of course material science has improved over the years with all sorts of fancy and super light carbon compounds developed. So, a pointy nose would get very hot, so perhaps modern materials can cope with this issue now. One would not want to change the nose every flight!

https://aviation.stackexchange.com/questions/24414/why-when-is-the-blunt-nose-better

This is WAY beyond my pay scale as I only touched on calculating Reynolds numbers for determining the stability of closed loop flow systems and have never used any of this since college 33 years ago. I skipped right down to the conclusion of this paper and gleaned the following:

"The results show that the bluntness has a strong stabilizing effect on the stability of the boundary layers. The transition Reynolds number increases slowly up to a nose Reynolds number of 30,000 and then increases sharply at higher nose Reynolds numbers. The transition Reynolds number for a cone at a nose Reynolds number of 65,000 is about 1.8 times larger than that for the Blasius boundary layer. This is due to the entropy layers that are generated near the leading edges. These layers persist for longer distances with increasing bluntness. There may be other unstable modes in the entropy layer as were observed in the experiments1 other than the first-mode type instabilities that were considered in this paper. Whether they exist and what role these waves play in the transition process still has to be investigated.

At small bluntness case, the disturbances grow starting from the nose region and reach very large values ~0.50 near the transition point. The growth of the first mode is much stronger for this case due to the non-parallel effects. The amplitude levels of the disturbances are much smaller in the order of 10-4 in the larger bluntness cases. There is no unstable first modes in the large bluntness cases and the disturbances decay by two orders before they start to grow due to the second mode instability. "

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070028873.pdf

So, for a amateur layman like me, "blunt" is the way to go for hypersonic flight! Pointy nose for supersonic flight

This is at the very extreme regime of flight and I hope it's pursued. High drag and stability was a good thing for the blunt nosed X-15, Shuttle, X-37, etc, but drag is a bad thing of course for airliners. Pointy nose suggests less stability at high mach numbers and there is the whole thermal effects on a pointy nose versus a blunt nose. It's a pretty interesting topic.

[Ansett A330]

... hypersonic (Mach 4 up) ...

Mach 5 to 10 is apparently the definition for "Hypersonic".

[BradG]

Ok, cool.