Forum: General F-22A Raptor forum

wrightwing wrote:

southernphantom wrote:

By then there's a reasonable chance we will have fought T-50s and J-20s. I personally hope for a T-50 silhouette or two on the canopy rail of my Raptor, Beagle or F-35, because if all goes according to plan I'll be a USAF O-3 or higher at that point.

If you become a pilot, hopefully you'll never have to be involved in combat. That's the ultimate goal.

You're right, but it's an untenable one in this day and age. The only question is whether I'll be in and with an FS when the shooting starts. God willing, it would just be a conflict with Iran or the DPRK that generally left everyone better off, not a major war. I can't stomach the thought (and I've heard, reality in the Cold War) that my survival chances on the frontline would be better than those of my family and friends back home.

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southernphantom wrote:

tacf-x wrote:

I'm thinking the combined cycle SABRE air breathing rocket engine seems like a good idea for LEO insertion.

http://www.reactionengines.co.uk/sabre.html

That is some truly crazy-awesome tech.

I'll give you 'truly crazy'... Doh

"an intake here at the front which can accept up to 400kg [880lb] per sec of air the air then finds it's way though the intake and is now traveling subsonically ...then flows into the engine, through this large drum like structure which is a big heat exchanger, which we call a precooler, and this is basically using, indirectly, the low temperature of the liquid hydrogen fuel as a heat sink, via a clever thermodynamic cycle which i won't go into in too much detail... ...so in a few milliseconds it takes for the air to flow in through these thousands of small tubes, the air can get cooled from perhaps 1000*C [1832*F] at Mach 5 on the outside down to about -150*C [-238*F] here on the inside... ...at which point you can then compress it to very high pressures, in this jet engine style compressor, this has a pressure ratio of 150/1, which is about 5 times higher than a normal flow jet engine.... ...air then comes out of the compressor at around 150 bar [2175.5PSI]....."

So they're taking MACH 5 airflow up too 880lbs/sec, shock-trapping it into the engine, running it through an inter-cooler at a high flow rate, cooling it to -238*F 'in a few milliseconds" then running it through a 150/1 compressor until it is over 2000PSI...

And this "clever" thermodynamic process that uses liquid helium, three heat exchangers, four turbines, driving two liquid fuel pumps and a "He Circulator" not to mention the 150/1, 2000+PSI compressor...

And to think Rutan used a hybrid solid rocket motor; what was he thinking simplicity? Salute

"When the project starts for real it will be about 12 to 15 years of engineering development before you have an actual viable vehicle that you could start operating"

I doubt you'd see this in a military fighter of any type inside 20 years. (If they can get it to work) Figure the YF120 lost out because of 'assumed risk' in a variable-cycle design, it's unlikely something like the SABRE cycle engine would see widespread use in a fighter application. Maybe reconnaissance or space delivery/retrieval to take the place of expendable launchers, but even then this seems very expensive compared to 'cheap' disposable rocket technology. You think of how much engines of this sort would be to maintain? (Space Shuttle engines had a burn time of 480 seconds per flight and that was their TBO.) Using an 'aircraft' with this sort of engine technology, in the near future, would be a money hog. Think SR-71 costs...

I'll still lay my $$ on hydrocarbon fueled SCRam jets betting a SABRE cycle engine into 'regular' use. Pratt & Whitney's SJY61 scramjet engine powered the X-51 for 140 seconds at MACH 5 using JP-7. (the same fuel the Blackbird's J58s used for MACH3+)

Looks like the hybrid-rocket is beating them both! SpaceShipTwo should be providing 'flights' into space by 2013.

Keep 'em flyin' Thumb

TEG

Thanks for the input TEG. So a simple variable cycle then? Smile

Per the Lockheed design, I have three possible origins for the plane.

1) Pure artist's fantasy. Has no connection with the Lockheed 6th gen design office, just drawn out of thin air.
2) Product of Lockheed business development. Lockheed wants the USAF to spend a lot of time designing a 6th gen fighter. That long development cycle gives Lockheed a monopoly over US fighter development in the shot term. Notice how Lockheed wants a 6th gen fighter, with technology "currently not even imagined." That is the recipe for a long R&D cycle.
3) What Lockheed 6th gen fighter office, independently of the previous two ideas, actually things will work.

What I find interesting is this is a unabashedly fast design. Boeing and Northrup look to be going for more long range and pure stealth. This looks to be a really fast airplane.

Personally, I think the USN / USAF should buy a 5+ gen fighter, from Boeing or Northrup, in the 2015 - 2020 range, before pursuing a 6th gen fighter.

arkadyrenko wrote:

Per the Lockheed design, I have three possible origins for the plane.

1) Pure artist's fantasy. Has no connection with the Lockheed 6th gen design office, just drawn out of thin air.
2) Product of Lockheed business development. Lockheed wants the USAF to spend a lot of time designing a 6th gen fighter. That long development cycle gives Lockheed a monopoly over US fighter development in the shot term. Notice how Lockheed wants a 6th gen fighter, with technology "currently not even imagined." That is the recipe for a long R&D cycle.
3) What Lockheed 6th gen fighter office, independently of the previous two ideas, actually things will work.

What I find interesting is this is a unabashedly fast design. Boeing and Northrup look to be going for more long range and pure stealth. This looks to be a really fast airplane.

Personally, I think the USN / USAF should buy a 5+ gen fighter, from Boeing or Northrup, in the 2015 - 2020 range, before pursuing a 6th gen fighter.

A- in order to get a 6th Gen fighter in the 2025/2030 timeframe, designs have to start now.

B- it's impossible for Boeing/Northrop to field a 5+ Gen aircraft in the 2015/2020 time frame.

C- the F-22 and F-35 will be upgraded over their lives, resulting in 5+ Gen capabilities before it's all said and done.

Forum: General F-22A Raptor forum

Artist's rendering - Miss February - 6th generation fighter