LM Aerodynamic Wizardry, CL_max, and Vapes

Design and construction
  • Author
  • Message
Offline

hornetfinn

Elite 2K

Elite 2K

  • Posts: 2941
  • Joined: 13 Mar 2013, 08:31
  • Location: Finland

Unread post02 Jan 2020, 12:36

I wonder if there is any difference in achieving this kind of maneuverability with or without TVC? For example Su-35 (and F-22) is similar in being good at both types of fight (energy/turn rate and high AoA/turn radius). AFAIK, turning the TVC nozzles means that less thrust is used going forward as some thrust goes to turn the fighter. Without TVC all the thrust goes to moving forward and control surfaces do all the turning stuff. It sounds a bit more efficient to not use TVC if not necessary to turn the aircraft. Of course Su-35 and F-22 have a lot of thrust, so "losing" some of that in high-AoA maneuvers is not necessarily that bad for them.
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4602
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post02 Jan 2020, 14:35

the use of TVC (as IIRC on the F-22 it is only for use below 250 knots) means you are not playing the "sustainable rate" game anymore and are playing an angles game. You actually are having MORE thrust go "forward" as the AoA of the aircraft is higher than the deflection of the TVC nozzles, but to balance the AoA (in the F-22) the tailplanes have to "hold up" the tail (make more lift, and drag) otherwise the plane will just tumble balistically (Su-35) at stalled AoA.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline

hornetfinn

Elite 2K

Elite 2K

  • Posts: 2941
  • Joined: 13 Mar 2013, 08:31
  • Location: Finland

Unread post02 Jan 2020, 14:45

That makes perfect sense, thank you sprts! I'd really like to hear what pilots of both F-22 and F-35 have to say about facing each other. I bet both find the other rather difficult opponent in WVR compared to 4th gen jets.
Offline
User avatar

ricnunes

Elite 2K

Elite 2K

  • Posts: 2343
  • Joined: 02 Mar 2017, 14:29

Unread post02 Jan 2020, 14:58

I also remember to have read somewhere which quoted an interviewed F-22 pilot where he stated that the main advantage that TVC brought to the F-22 was not during dogfights (sharp turns) but instead to make "simple turns" at very high altitudes such as 60,000 ft where the air is extremely thin and thus the "traditional" control surfaces such as ailerons won't respond very well and as such TVC becomes handy since it makes the aircraft respond/turn better than solely relying on control surfaces (again at those very high altitudes).
“Active stealth” is what the ignorant nay sayers call ECM and pretend like it’s new.
Offline

mixelflick

Elite 3K

Elite 3K

  • Posts: 3608
  • Joined: 20 Mar 2010, 10:26
  • Location: Parts Unknown

Unread post02 Jan 2020, 15:27

hornetfinn wrote:That makes perfect sense, thank you sprts! I'd really like to hear what pilots of both F-22 and F-35 have to say about facing each other. I bet both find the other rather difficult opponent in WVR compared to 4th gen jets.


The point about it being a very difficult aircraft to dogfight due to its ability to rate/radius.... I immediately thought of the Flanker. If you think about it, that's a BIG part of what makes it so dangerous. It's no slouch in the rate dept, and a good argument could be made its the best nose pointer of all...

But it won't make it to the merge with the F-35. And if it does, it'll be a LOT easier to see with the MK1 eyeball. Not that the F-35 pilot will even have to do that. One of the most powerful illustrations I've ever seen of its technology was a furball with multiple friendly's/bandits. Automation clearly identified who was hostile and who wasn't, such that it'll probably be getting first look/first shot/first kill there too.

If you study a lot of the Desert Storm dogfights, there was still concern among F-15 pilots due to the Mig-25/29 looking so similar. They closed the distance and VID'd them in more than one case. Doesn't sound like that'll be an issue in the F-35..
Offline
User avatar

sferrin

Elite 5K

Elite 5K

  • Posts: 5476
  • Joined: 22 Jul 2005, 03:23

Unread post02 Jan 2020, 17:53

ricnunes wrote:I also remember to have read somewhere which quoted an interviewed F-22 pilot where he stated that the main advantage that TVC brought to the F-22 was not during dogfights (sharp turns) but instead to make "simple turns" at very high altitudes such as 60,000 ft where the air is extremely thin and thus the "traditional" control surfaces such as ailerons won't respond very well and as such TVC becomes handy since it makes the aircraft respond/turn better than solely relying on control surfaces (again at those very high altitudes).


Also trimming while keeping controls surfaces neutral for stealth.
"There I was. . ."
Offline

marauder2048

Forum Veteran

Forum Veteran

  • Posts: 822
  • Joined: 14 Mar 2012, 06:46

Unread post03 Jan 2020, 03:45

sprstdlyscottsmn wrote:the use of TVC (as IIRC on the F-22 it is only for use below 250 knots)


I believe that's strictly for AoAs <= 12 degrees.

sprstdlyscottsmn wrote:as the AoA of the aircraft is higher than the deflection of the TVC nozzles, but to balance the AoA (in the F-22) the tailplanes have to "hold up" the tail (make more lift, and drag) otherwise the plane will just tumble balistically (Su-35) at stalled AoA.


The AoA and nozzle deflection angles should match each other through 20 degrees i.e. the maximum deflection
angle of the nozzle.
Offline

hornetfinn

Elite 2K

Elite 2K

  • Posts: 2941
  • Joined: 13 Mar 2013, 08:31
  • Location: Finland

Unread post03 Jan 2020, 10:32

I wonder how EF Typhoon with AMK kit might compare with F-35? Airbus is promising some rather good numbers like 45% higher max angle of attack and 100% increased roll rate. Of course flight conditions for those have not been released.
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4602
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post03 Jan 2020, 15:37

marauder2048 wrote:
sprstdlyscottsmn wrote:as the AoA of the aircraft is higher than the deflection of the TVC nozzles, but to balance the AoA (in the F-22) the tailplanes have to "hold up" the tail (make more lift, and drag) otherwise the plane will just tumble balistically (Su-35) at stalled AoA.


The AoA and nozzle deflection angles should match each other through 20 degrees i.e. the maximum deflection
angle of the nozzle.

Correct, but then the line of thrust will be below the center of gravity and would as such be trying to increase the AoA further.

hornetfinn, I would like to see that too but so far no country has ordered the AMK.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline
User avatar

ricnunes

Elite 2K

Elite 2K

  • Posts: 2343
  • Joined: 02 Mar 2017, 14:29

Unread post03 Jan 2020, 19:27

sprstdlyscottsmn wrote:hornetfinn, I would like to see that too but so far no country has ordered the AMK.


IMO that AMK kit is just like the Captor-E radar. I believe it when I actually "see it"...
“Active stealth” is what the ignorant nay sayers call ECM and pretend like it’s new.
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4602
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post03 Jan 2020, 19:39

My understanding is that the UK is getting Tranche 3 aircraft with improved EuroDASS, Captor-E, and SPEAR-3. AFAIK Tranche 3 "capabilities" that are unfunded are the CVT, TVC, Uprated EJ200, and AMK. I could be wrong though.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Online
User avatar

marsavian

Elite 1K

Elite 1K

  • Posts: 1530
  • Joined: 02 Feb 2018, 21:55

Unread post03 Jan 2020, 20:25

ricnunes wrote:
sprstdlyscottsmn wrote:hornetfinn, I would like to see that too but so far no country has ordered the AMK.


IMO that AMK kit is just like the Captor-E radar. I believe it when I actually "see it"...


Kuwait and Qatar exports being built now will have them, it is explicit in their contracts. These are the early versions with no EW functionality. The UK and possibly Germany too, with its new orders, will be getting later versions with EW capability whereas the general European retrofit will be a similar but updated standard to the export version. Tranche 3 and Tranche 2 (more work) can be retrofitted.

https://www.ainonline.com/aviation-news ... er-typhoon
Offline
User avatar

ricnunes

Elite 2K

Elite 2K

  • Posts: 2343
  • Joined: 02 Mar 2017, 14:29

Unread post04 Jan 2020, 00:17

marsavian wrote:Kuwait and Qatar exports being built now will have them, it is explicit in their contracts.


Well, I've been reading about the Captor-E 'saga' almost a decade ago.
I've been reading since at least 2010 that the Captor-E was ready to be integrated in the Typhoon. Fast-forwarding to today (at least 10 years later) and still no Captor-E is installed and operational in any operational Typhoon.

So yeah, feel free to call me skeptical!
“Active stealth” is what the ignorant nay sayers call ECM and pretend like it’s new.
Online
User avatar

marsavian

Elite 1K

Elite 1K

  • Posts: 1530
  • Joined: 02 Feb 2018, 21:55

Unread post04 Jan 2020, 03:18

Yes, TyphoonWorld can be very vague and nebulous at times primarily because the four main partners all want to go at different development speeds leading to very little coordinated agreement on development with the UK usually leading and the rest adopting a belated pick and mix approach on updates. Even the UK though is slow in developing compared to say the French with some articles saying the Phase 2 Aesa is only a proof of concept at the moment and that Tranche 2 may not be so easy to retrofit the Aesa in practice so a wait and verify is needed on both those. Going forward the Germans may take over the lead development role as they will be ordering new ones again and Airbus is promising all sorts of enhancements. On release Typhoon met its original design goal of countering the Su-27 but further development has been slow compared to all of its contemporaries.
Offline
User avatar

ricnunes

Elite 2K

Elite 2K

  • Posts: 2343
  • Joined: 02 Mar 2017, 14:29

Unread post05 Jan 2020, 18:24

marsavian wrote:Going forward the Germans may take over the lead development role as they will be ordering new ones again and Airbus is promising all sorts of enhancements.


Which will likely spell much worse news for the Typhoon program when it comes to future development/upgrades, LoL :doh:

(IMO, that is...)
“Active stealth” is what the ignorant nay sayers call ECM and pretend like it’s new.
PreviousNext

Return to F-35 Design & Construction

Who is online

Users browsing this forum: No registered users and 10 guests