Hypersonic drag reduction with forward energy deposition.

originally posted by: Zaphod58
a reply to: DexterRiley

If you want them to go straight, and really far, yes. You can't maneuver at those speeds without breaking apart any kind of aerodynamic body. You could maneuver slightly, and a hypersonic missile would be scary as hell against larger platforms, like tankers, or B-52s, but they'd have the same problem we had with the Phoenix. Against a small, maneuvering target, they'd have a harder time making kills.

Could this technology be used to create a hypersonic version of a Tomahawk cruise missile?

Russia claims to have a hypersonic nuclear missile that is impervious to US anti-missile defenses.

-dex

a reply to: DexterRiley

That's an ICBM. All of them are hypersonic. Your best bet for a hypersonic missile is actually a boost glide weapon. It uses a rocket to accelerate to hypersonic speeds, and the upper atmosphere, then detaches and has a much flatter trajectory. It's extremely difficult to intercept, without the problems that have been had developing hypersonic anti ship or cruise missiles.

a reply to: Zaphod58

knew it.

a reply to: penroc3

The unit commander at the time said, "That was our first clue this stealth # really worked".

a reply to: DexterRiley



like this but with a boom not a parachute

a reply to: Zaphod58

was it just a by product of the RAM or was ultrasound mitigation a primary concern? i cant imagine what would be using ultrasound as a detection method for high speed aircraft but who knows.

i always wondered about the LIDAR on the refueling rigs and stealth aircraft.

a reply to: penroc3

It was a byproduct of the RAM. It did as it was supposed to and trapped the sonar under the skin. The poor bats didn't stand a chance.

a reply to: Zaphod58this might show my ignorance but if the energy from radar and whatever other wavelengths the RAM absorbed and kept in the structures underneath how did all that energy get dissipated? heat? or was it discharged on the ground? that seem dangerous. both of those methods have obvious drawbacks. i would imagine in highly contested airspace the air would be saturated with high power RADAR and if the skin is absorbing it the energy has to go somewhere.

a reply to: penroc3

It's generally dissipated as heat, or in the case of the F-117, some was simply redirected away from the antenna.

a reply to: Zaphod58

true enough, the defection probably takes most of it away and any heat would be cooled by the air flow would be my theory.


i wonder if the radar people took a cue from the bats and used different wavelength to find holes in the sky, but i guess you would have to have a general idea of where to aim your hole finding radar.

i know they claim the newer radars using Xband(i think) longwave anyway claims to be able to find these holes

a reply to: penroc3

X-Band is fairly short wavelength. They use it for fire control. They're usually talking like S band, or L I think, somewhere in that range.

originally posted by: penroc3
how do bats fly again, ultrasound. eiter the nighthawk was absorbing the ultrasound or emitting it would be my guess.

Or just simple high-school physics and wave propagation. But hey, that's less exciting...

originally posted by: Zaphod58
a reply to: penroc3

The materials in the aircraft absorbed their sonar, so they saw an open space in front of them and flew into them.

Reflected. In a different direction. Not absorbed. It's shape, not materials.

a reply to: mbkennel

This is sort of a dead end, and sort of not.

The primary concern is material science. And once you have a material that can withstand the environment involved, why not just use it for your vehicle instead of producing another shockwave?

Right now it's all about shaping the leading edge to get similar results and other fringe benefits. For example, how do you transmit or receive data with all that ionization going on?

a reply to: RadioRobert

it gets absorbed and reflected, i know how stealth works but it is usually made to do that with radar bands i was unaware the ultrasound would do the same.

i didnt know for sure so i asked, is there something wrong in asking if my hunch was right?

It's basically just reflected. The sound waves propagate the same way radio waves do.

You can even make a three-corner reflector for sound, going the other way.

The amount of energy lost in a sound wave reflecting off a surface is relatively small. The RAM should have a near-zero effect. Air itself probably absorbs more high-frequency sound.

a reply to: mbkennel

I got my knuckles rapped by following the trail of papers and data about 'waverider' tech which is one way of reducing drag for hypersonic vehicles.

Started out looking at research and papers from the University of Aberdeen and followed the trail of links to what I assumed was NASA.

Turned out to be an Air Force server and the data was not supposed to be available to non-US nationals (got a letter in the post).

But this was late 80's, so I think security would be tighter these days (and, perhaps, the tech declassified).

a reply to: chr0naut

There is so much overlap with work done on RV's since the 50's and the hundreds of hypersonic progams since that it is sort of surprising the things out on DTIC and such sometimes.

a reply to: chr0naut
A letter in the post, mehh...
I dont imagine that really mattered to anyone in your part of the world. What can they do, use harsh language or invade NZ?
Sounds more like someone in the US Air force should be getting their knuckles rapped for allowing such a security breach in the first place.

originally posted by: thebozeian
a reply to: chr0naut
A letter in the post, mehh...
I dont imagine that really mattered to anyone in your part of the world. What can they do, use harsh language or invade NZ?
Sounds more like someone in the US Air force should be getting their knuckles rapped for allowing such a security breach in the first place.

The letter was actually from some US Catholic University but had nasty implied overtones (to me) and said I was to destroy the info. I didn't actually retain any of the info, anyway. I had just read it and moved on.

I was living in Australia at the time and working for an Aussie Aerospace Defence contractor, so I was no stranger to the presence of CIA agents (who were crap at hiding it).

I actually worked where John Nugan had set up a credit union associated with the Nugan-Hand Bank. Nugan "comitted suicide" (according to the reports) but a business card of William Colby (former CIA director) was found on the body - go figure.



Anyway, I'm literally 1,000 miles from there and it was years and years ago.