Su-27 experts, I need help

[+76.IAP-Blackbird]

Take a look into those intakes, there are two "slats" modeled, th4ey seem to work like variable intakes, similar like the ones on the F-111 or the F-15 with their moving intakes.

 

 

I need some Data how those slats work and on wich speeds, I would ask JAT if he would like to make the right entries for the Su-33UB Flanker-D. Those parts are already modeled on my plane I only need some info about the degrees and speed they deply.

 

hope you can help me out

 

best regards

 

Martin

[+76.IAP-Blackbird]

After a longer google search those were called "ramps" wich move down when the plan reach higher speeds, something about mach 1 but still no infos about the real speed. Hope lindr2 can help out.

 

The airflow will be pushed further and better into the engines on higher speeds trough out this variabel geometry intake ramps.

 

More info is welcomed

[Caesar]

Those look almost identical to the Tomcat's Ramps. I'm afraid I don't have the Su-27's numbers, maybe to help ball-park it for the F-14 they don't activate until .35M, and then don't normally move until .5M. Ramps 1 and 2 start at .5M and Ramp 3 at .9M. The aircraft is limited to below 1.2M in the event of Ramps failure.

[+76.IAP-Blackbird]

Thx for the info, now I need to work out the ini entry for it, still a noob when it comes to ini editing..

 

JAT has done a damn good work with the FM, but the rest... I have no idea..

[+76.IAP-Blackbird]

does it work like this?

 

[Rampelinks]

SystemType=HIGHLIFT_DEVICE

AreaRatio=1.02

DeploymentMethod=AUTOMATIC_SPEED

MaxDeflection=30.0

MinDeflection=0.0

Setting[1].Angle=30.0

Setting[1].DeployValue=720.0

Setting[1].RetractValue=700.0

AnimationTime=2.0

ModelNodeName=Rampelinks

AnimationID=10

 

[Ramperechts]

SystemType=HIGHLIFT_DEVICE

AreaRatio=1.02

DeploymentMethod=AUTOMATIC_SPEED

MaxDeflection=30.0

MinDeflection=0.0

Setting[1].Angle=30.0

Setting[1].DeployValue=720.0

Setting[1].RetractValue=700.0

AnimationTime=2.0

ModelNodeName=Ramperechts

AnimationID=10

 

ist the speed kph or knots?

[+Fubar512]

If I'm not mistaken, those are inlet debris screen, similar to the ones on the MiG-29

 

 

"[2] SU-27 INTO SERVICE

* The production Su-27 clearly retained much of the look of the original T10, but the changes were visible and obvious. The most apparent change was the adoption of a larger wing that featured straight edges, replacing the curved wing of the T10. Other visible changes included:

 

 

Moving the twin vertical tailplanes from positions directly atop the engines to just outboard of the engines.

 

Moving the nosewheel back behind the cockpit to reduce engine ingestion of debris during ground operations, and for the same reason installing inlet debris screens that retract and extend along with the landing gear.

 

Twin ventral fins."

 

Source: http://www.faqs.org/docs/air/avsu27.html

Edited September 18, 2009 by Fubar512

[+76.IAP-Blackbird]

The 29 has the additional intakes on the top of the fuselage, the two screen protect the jetengine on landing and start procedure. The 27 has similar ramps but they look like this here

 

 

they can`t be solid like the one of the 29 cause the 27 has no additional intakes. Only on landing and start on the down site are some fins wich opens but this cover is still between the engine and the intake.

 

The ramps shown in the first pic in this topic work as variable intakes.

[+Fubar512]

From: http://ma.hit.bg/su27history/history1.html

 

While preserving the general arrangement of air intakes, the new aircraft had a new foreign-object damage (FOD) system introduced for preventing FOD during taxiing, run and take-off through the use of extendable screens in the air intakes' ducts. Supplementary air inlet ramps were added to the lower surface of the air intakes.

 

So the supplemental intakes are probably under, and aft of the main inlets, like the ones outlined in red, below:

[+76.IAP-Blackbird]

Yes you are right I think we are talking about two different things, pls take a look on this and you can see (number 40) you can see the bars of the engineprotector and the ramp infront of the bars.

 

 

 

never knew the 27 family has such system installed, the downsite inlets and the ones on the site will be modeled to

[+Fubar512]

I realize that we're talking about two different systems, but you did state that the Su-27 lacked the supplemental intakes that the MiG-29 had, and I showed you that it does not.

 

The MiG-29's intake shields are not there just for FOD-protection, they also close during high-alpha states. This is due to the inlet's position, below and behind the LERXs (Leading Edge Root Extensions). During high-alpha flight, the LERXs would all but cut off airflow to the power plants, so the upper intakes open, to provide clean (non-turbulent) airflow. I believe that a similar system is utilized on the Su-27, through the lower and nacelle-side intakes.

[Wraith27]

Maby this helps...

 

 

http://forums.airforce.ru/showthread.php?p=45705

 

UPDATE 1.0

 

http://www.aircraftresourcecenter.com/Rev3/2401-2500/rev2429-Zacto-su-27combo/00.shtm

 

UPDATE 2.0

 

http://www.zactomodels.com/html/Intake%20instructions%20pg2.pdf

 

UDATE 3.0

 

http://www.b-domke.de/AviationImages/Flanker.html

Edited September 18, 2009 by CIACHO

[+76.IAP-Blackbird]

Ah ok, I see what you mean, yes that`s right, I hope I can model this feature into the plane, remodeling the enginenazelles completly, smoothing them and cut out those additional inlets, the next step will be to animate them and the needed ini entry. Do I need an animationslot for them? I think yes, what about the ramps are they the same like slats?!

 

I have the feeling I`m running out of animation slots, will kill the ladder animation and put it back on the stationiary LOD, so this is solved..

 

thx fubar for those informations. do you have any idea how the entry could look for the ramps?

[+76.IAP-Blackbird]

@ Ciacho, thx for those infos, found some interesitng stuff, it seems that only the inlets unde rthe nacelle are movable and the ones on the sides are fixed..

 

[+76.IAP-Blackbird]

@ Ciacho found the solution, the FOD`s move from downside up take a look o nthem here

 

 

great video and a nice teaser for my self :-P

[+FastCargo]

If they are simple doors, you do not need an animation slot if they simply rotate. Just put the pivot like another surface, and 'animate' them like the F-15 intake ramps (as an example).

 

FC

[+76.IAP-Blackbird]

Thx Fastcargo, will take a look on the F-15 parts... all this stuff is a bit new to me so excuse my neverending questions