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alfadriver
alfadriver MegaDork
12/21/15 1:13 p.m.
aircooled wrote: The real question to ask is: why don't all pre-supersonic jets look like them (and many do). One of the prime reasons for this is that the F86 & Mig both use then then somewhat new axial flow engine design. Earlier jets used the original (Whipple designed) radial flow layout which are much shorter and fatter. Examples of that style are the Vampire and the P80 / T33:

Actually, the MiG used the whipple design- this engine https://en.wikipedia.org/wiki/Klimov_VK-1

Which, apparently, was based on a RR engine that the British SOLD to the Soviets. Interesting story behind it.

WildScotsRacing
WildScotsRacing Reader
12/21/15 1:32 p.m.

SOmeting missing from the aerodynamics part of this discussion; All 4th Generation fighters (F-14, F-15, F-16, F-18, Mig 29 series, Su-27 series) and 5th Gen fighters all have the wing blended into an airfoil-shaped fuselage. The fuselage itself generates a significant portion of the total lift of the airplane, an extreme example being the F-14; the Tomcat generated enough lift from the body alone (60% of total lift at full sweep) that it would have could have flown and maneuvered at speeds as slow as 260 knots with the wings totally removed, using differential horizontal stabilizer movement, and this was tested by Grumman using scale wind tunnel models. Some years back, two Israeli F-15s had a mid-air during a dogfight training flight, resulting in the loss of one jet. The surviving jet had the left wing 100% removed right at the wing root almost as clean as if a giant bandsaw had removed it. The pilot still had enough total lift to maintain control and was able land back at his base with a touchdown speed of 230 knots (100 knots faster than normal landin speed) using the tail hook runway barrier system. The purpose of all this body-generated lift is that it allows the wings to be MUCH smaller while giving the jets as low a wing loading as possible, which allows extremely hard, tight turning but with reduced lift-generated drag during the turn, meaning the jet can sustain the hard turn longer because airspeed doesn't bleed down as quickly. All while keeping total drag low enough for supersonic flight, when needed.

Apexcarver
Apexcarver PowerDork
12/21/15 3:07 p.m.

In reply to GameboyRMH:

I have a box where I put some parts that I had planned to do just that.

Might have to dig that project back out. Turbo was from an MR2

AngryCorvair
AngryCorvair GRM+ Memberand UltimaDork
12/21/15 3:28 p.m.

I love this forum!

Toyman01
Toyman01 GRM+ Memberand MegaDork
12/21/15 5:48 p.m.
tuna55 wrote:
GameboyRMH wrote: Fun fact: You know how you can build a jet engine from a turbocharger, by feeding the compressor output into the turbine inlet? The radial flow jets in early jet aircraft were basically just a giant version of that.
Yes! https://grassrootsmotorsports.com/forum/build-threads-and-project-cars/the-next-project-gas-turbine-content/48381/page1/

I haven't thought about that one for a while. There are two plastic tubs full of parts I might have to dig through after the first of the year.

codrus
codrus GRM+ Memberand Dork
12/21/15 6:50 p.m.
Karacticus wrote:
Appleseed wrote: The J-58 is the only jet rated for continuous, full, afterburner.
I'll be that nerd-- so were the Olympus engines on the Concorde.

And the YJ-93, although since they only made two XB-70s that may not count as a production engine. :)

Knurled
Knurled GRM+ Memberand MegaDork
12/21/15 9:22 p.m.
AngryCorvair wrote: I love this forum!

Do these guys know how to party or what?

Knurled
Knurled GRM+ Memberand MegaDork
12/21/15 9:24 p.m.
codrus wrote: And the YJ-93, although since they only made two XB-70s that may not count as a production engine. :)

The Valkyrie is my favorite example of Cold War excess. It's just so... absurd. Let's make a Mach 3 long range bomber!

Then integrated circuits were invented, making ICBMs viable, and the plans were scrapped.

XLR99
XLR99 GRM+ Memberand HalfDork
12/21/15 9:27 p.m.

Oooh, we're getting danger close to figuring out what my screen name is from... Only person to verbalize it so far was a kid on a bicycle forum.

That XB-70 pic is why everybody should try to get to the Air Force Museum in Dayton. Walking around the R&D and presidential hangar is pretty humbling and awe inspiring for many reasons.

tuna55
tuna55 MegaDork
12/21/15 9:30 p.m.
Knurled wrote:
codrus wrote: And the YJ-93, although since they only made two XB-70s that may not count as a production engine. :)
The Valkyrie is my favorite example of Cold War excess. It's just so... absurd. Let's make a Mach 3 long range bomber! Then integrated circuits were invented, making ICBMs viable, and the plans were scrapped.

Love the Valkyrie! What a weird plane!

tuna55
tuna55 MegaDork
12/21/15 9:30 p.m.
XLR99 wrote: Oooh, we're getting danger close to figuring out what my screen name is from... Only person to verbalize it so far was a kid on a bicycle forum. That XB-70 pic is why everybody should try to get to the Air Force Museum in Dayton. Walking around the R&D and presidential hangar is pretty humbling and awe inspiring for many reasons.

Still need to go!

tuna55
tuna55 MegaDork
12/21/15 9:31 p.m.

Also: Was the MiG 31 as impressive as it sounds? Intercepting the SR-71 and all? Or... is it typical Russian overpromising?

Brian
Brian MegaDork
12/21/15 9:53 p.m.
tuna55 wrote: Also: Was the MiG 31 as impressive as it sounds? Intercepting the SR-71 and all? Or... is it typical Russian overpromising?

What I have heard was it's upper capability was a "one and done". It was designed to get up to M3 long enough to launch the missiles and hopefully not fall apart.

kazoospec
kazoospec SuperDork
12/21/15 9:55 p.m.
tuna55 wrote:
XLR99 wrote: Oooh, we're getting danger close to figuring out what my screen name is from... Only person to verbalize it so far was a kid on a bicycle forum. That XB-70 pic is why everybody should try to get to the Air Force Museum in Dayton. Walking around the R&D and presidential hangar is pretty humbling and awe inspiring for many reasons.
Still need to go!

Plan two days. I could spend a full day in the "Cold War" exhibit alone.

pres589
pres589 UberDork
12/21/15 11:15 p.m.

I always thought the MiG-25 "Foxbat" was the hot rod and not the -31. That was a "one and done" setup; exceed ~ Mach 2.6 and the engines go into run-away to a top speed of Mach 3.2. Plus Foxbat just sounds cool; Foxhound sounds pedestrian in comparison, somehow.

WildScotsRacing
WildScotsRacing Reader
12/21/15 11:28 p.m.
Brian wrote:
tuna55 wrote: Also: Was the MiG 31 as impressive as it sounds? Intercepting the SR-71 and all? Or... is it typical Russian overpromising?
What I have heard was it's upper capability was a "one and done". It was designed to get up to M3 long enough to launch the missiles and hopefully not fall apart.

I believe the Foxhound has a VnE (never exceed speed) of 3.2 Mach, which should only be maintained for a maximum of something like 30 seconds or very bad things will happen to the engines. It has hard redline sustained speed of 2.82 Mach. Which can still only be maintained for about three minutes because the tanks will run dry. Modern fighters (the MiG-31 is NOT a dogfighter in any sense of the term) do not employ max afterburner for more than a few minutes total during any combat mission because the rate of fuel burn won't allow any sort of range if they did. Perspective: the F-16, which I know quite thoroughly from my time with the 138th, has an internal fuel capacity of 7200 pounds. At max AB and max thrust output, that engine burns on the order of 42,000 pounds per hour; it will litterally run the internal tanks dry in 6 minutes. In a 90 second close-in maneuvering dogfight it is not unusual for the F-16 to burn up between 3000 and 4000 pounds of fuel.

aircooled
aircooled MegaDork
12/22/15 12:38 a.m.
alfadriver wrote: Actually, the MiG used the whipple design- this engine https://en.wikipedia.org/wiki/Klimov_VK-1 Which, apparently, was based on a RR engine that the British SOLD to the Soviets. Interesting story behind it.

Doh! Well the second gen engines where much longer. Not sure why, they didn't have after burners (I think the F100 was the first with that), but it certainly dictated the shape a lot.

Regarding the Mig 25/31: I think it is helpful to realize that the Soviet philosophy for fighters was essential as an air to air missile delivery system (kind of like a booster for the missiles). Get to the bomber, ripple fire HR and IR missiles, and leave (or explode, whatever ). This of course was part of a heavily radar controller focused air defense system.

The U.S. Actually had a similar philosophy, but moved away from it a far earlier. The Soviets I think actually got lucky with the Mig 21 in that it turned out to be pretty nimble considering it was effectively the mirror of the F104 (all motor at all costs interceptor), and the F104 is not something you want to get into a fight with (unless it was about looking totally bitchin' or doing ridiculously high speed rolls)

They didn't really have a dedicated dogfighter until the Mig29. Well after the U.S. I don't think anyone would consider the Mig 21 successor, the Mig23 (sort of a mirror of the F14) a dogfighter! Of course, the F14 was essentially designed as a Phoenix missile delivery system... and there is the F(yeah right)111, but that's a completely different flawed approach...

...what were we talking about again?

rocketrich
rocketrich New Reader
12/22/15 5:23 a.m.
XLR99 wrote: Oooh, we're getting danger close to figuring out what my screen name is from... Only person to verbalize it so far was a kid on a bicycle forum. That XB-70 pic is why everybody should try to get to the Air Force Museum in Dayton. Walking around the R&D and presidential hangar is pretty humbling and awe inspiring for many reasons.

I know what your screen name is, but I won't out you. YES!, the AF Museum in Dayton is a must do. The Pima Air Museum in Tuscon, AZ is also a must see if you are in that area as well. The auxiliary to the Smithsonian Air & Space Museum near Dulles, VA (Udvar Hazy or something like that) is also pretty fantastic as well.

KyAllroad
KyAllroad SuperDork
12/22/15 6:29 a.m.

Thanks for reminding me about the Dayton Museum guys. It's only about two hours away and I haven't been in a couple of years.

Pensacola NAS and Smithsonian Air & Space both this last summer though!

Appleseed
Appleseed MegaDork
12/22/15 8:04 a.m.

I think I figured out XLR99'S screen name like the week he joined. I know your X-15 secret.

BTW, it's Whittle, not Whipple, as in Sir Frank Whittle.

As I remember, the Olympus would not be in 100% AB outside of takeoff. I could be wrong.

aircooled
aircooled MegaDork
12/22/15 8:23 a.m.

Whipple = Crazy screw air pusher

Whittle = Screaming spinny flame maker

Got it.

For must see air museums, you need to add Chino into that. Lots of planes, lots of them fly! They are currently working on getting a P59 flying!

and they have a working, real, V1 motor (I really want to hear that run):

(note guys with fingers in ears!)

XLR99
XLR99 GRM+ Memberand HalfDork
12/22/15 9:13 a.m.

Collings Foundation world HQ (And soon to be TankLand ) is a couple miles from my parents' house. Also highly recommended, as much for the cars as the aircraft. They only open for a few events a year now, but very, very worth it. I got to talk to a B24 combat pilot for a couple hours last year!!! He was told that if he hit this cathedral (Cologne, I think) that he should not come back .

<img src="DSCN2057" />

Appleseed, it's definitely not a secret, but just a nerdy obscure reference I came up with like 15 years ago as a fun way to see who was as much of an aviation geek as I am. I had the data plate as my avatar on an aviation forum for years. I have issues...

Appleseed
Appleseed MegaDork
12/22/15 9:14 a.m.

They also have the only flying A6M Zero with it's Nakajima engine.

tuna55
tuna55 MegaDork
12/22/15 9:22 a.m.

In reply to XLR99:

Wait, are you saying you flew the X15, or worked on it firsthand?

Karacticus
Karacticus GRM+ Memberand Reader
12/22/15 9:44 a.m.
Appleseed wrote: I think I figured out XLR99'S screen name like the week he joined. I know your X-15 secret. BTW, it's Whittle, not Whipple, as in Sir Frank Whittle. As I remember, the Olympus would not be in 100% AB outside of takeoff. I could be wrong.

May not have been in 100% AB outside of takeoff. Had a guy from Rolls-Royce through when I was in school, he said that even with the relatively small fleet of Concordes, the Olympus fleet had more time in afterburner than any other engine type.

Also had a guy through from Lockheed Skunkworks to talk about the A-12/SR-71. His big takeaway was that they designed that airplane with slide rules, Friden mechanical calculators, graphite on paper and ink on mylar, and he's not going to make any apologies for that-- kids these days and their computers (get off my lawn)

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