Are lifting bodies and flying saucers aerodynamically viable?

[wolram]

Lifting bodies and flying saucers, are they aerodynamic or have properties
that are worth pursuing?

 

[FredGarvin]

Lifting bodies are most definitely a highly researched area in aerodynamics. The space shuttle is the most widely known lifting body aircraft today. NASA did a lot of lifting body work in the X series aircraft back in the '60s. The latest concepts for the hypersonic transports and future aircraft are all lifting bodies as well.

I don't think the flying saucer has any hope in our current technology. A couple of programs did look into it though.

 

[russ_watters]

The latest concepts for the hypersonic transports and future aircraft are all lifting bodies as well.

expansion: Hypersonic aircraft research is focusing on lifting bodies because of heat issues. On a plane with sharp edges, the shock wave is touching the aircraft and heat builds up there. Lifting bodies are blunt and create an insulating cushion of air between themselves and their shock wave. They literally ride their own shock wave (some have been called "waveriders").

 

[Ivan Seeking]

expansion: Hypersonic aircraft research is focusing on lifting bodies because of heat issues. On a plane with sharp edges, the shock wave is touching the aircraft and heat builds up there. Lifting bodies are blunt and create an insulating cushion of air between themselves and their shock wave. They literally ride their own shock wave (some have been called "waveriders").

Either Buzz Aldrin or Gordon Cooper once commented that a saucer shaped craft wouldn't create a sonic boom. I have no idea is correct or not, but apparently it was thought to be true at one time.

 

[russ_watters]

The way I understand it, the shock wave around a lifting body is curved, not sharp like on an angular aircraft and that causes the shock wave to be less concentrated and dissipate faster. And I guess with no nose at all, a saucer would have an even more irregular shock wave.

 

[quark]

It was observed that it was easier(actually the power required is lesser) to overcome gravitation by rotary motion when compared to thrust. The shape of flying saucers may have the reason of similar kind. If the top and bottom surfaces are designed aerodynamically and with rotary motion, the air resistance can be minimized.

Having said that, I confess I didn't make indepth study of the science. I often wonder them as the time machines of our future folks

 

[wolram]

Would a flying saucer be a lifting body? i have seen some wacky ideas to
make them fly.

 

[Clausius2]

expansion: Hypersonic aircraft research is focusing on lifting bodies because of heat issues. On a plane with sharp edges, the shock wave is touching the aircraft and heat builds up there. Lifting bodies are blunt and create an insulating cushion of air between themselves and their shock wave. They literally ride their own shock wave (some have been called "waveriders").

Just a comment. The last models of X series I've seen were not blunt nosed. It seems that blunt nose design is not the current way of making it better... I don't know why.

 

[FredGarvin]

The most roundest lifting body I can think of was the X-24:
http://users.dbscorp.net/jmustain/X-24a.jpg

 

[wolram]

The most roundest lifting body I can think of was the X-24:
http://users.dbscorp.net/jmustain/X-24a.jpg

Now that was a strange looking bird, if its what i recall, twin engined prop almost circular body?

 

[FredGarvin]

Now that was a strange looking bird, if its what i recall, twin engined prop almost circular body?

Nope. She was a bath tub shaped lifting body that had a rocket. This, believe it or not, was the great great great great great grandfather of the space shuttle.

 

[yourdadonapogostick]

Nope. She was a bath tub shaped lifting body that had a rocket. This, believe it or not, was the great great great great great grandfather of the space shuttle.

she was the great great great great great grandfather of the space shuttle?

 

[enigma]

Looks a lot like the X-38, IMO.

Lifting bodies will be used for any re-entry vehicle where you want or need to limit the g-loading on the passengers or cargo.

 

[sid_galt]

Just a comment. The last models of X series I've seen were not blunt nosed. It seems that blunt nose design is not the current way of making it better... I don't know why.

Assuming mach numbers of 10 and small deflection angles (angles of top or bottom surfaces witht the chord) like 20 degrees, the temperature rise is 4-5 times the ambient.
My book here says that providing best air compression to the scramjet is an essential consideration of the design.
Granted that the temperature 4-5 times the ambient would be quite high, given that these things operate at high altitudes where temperatures are low, I'll say temperature is not an overwhelming consideration.

 

[FredGarvin]

she was the great great great great great grandfather of the space shuttle?

Point taken! Good catch.

 

[Danger]

The most roundest lifting body I can think of was the X-24:
http://users.dbscorp.net/jmustain/X-24a.jpg

For shame, Fred! A fellow Avro fan failed to mention http://www.virtuallystrange.net/ufo/mufonontario/avro/avrocar.html?

 

[Ivan Seeking]

Here is the official US technical report on Project Silverbug; declassified in 1995.
http://www.cufon.org/cufon/Silverbug.pdf

 

[FredGarvin]

For shame, Fred! A fellow Avro fan failed to mention http://www.virtuallystrange.net/ufo/mufonontario/avro/avrocar.html?

I never thought that the Avro Car was an actual lifting body. Was it supposed to be? I'm going to have to check in on that one!

 

[FredGarvin]

That's a cool link Ivan. How do you find that stuff?

 

[Ivan Seeking]

"Mainstream" UFO literature.

There are a few sites that are quite reliable.