REAL PERFORMANCE of RD-33 and much more...

[SVK_Fox]

Hey folks, one guy from our community send us some interesting information about real performance od engines (he got detailed manual of RD-33 and its performance also manual to migs)and also SVK_Raimir done some test in LOckon. Maybe some information are known but I would like to share with some interesting details.

Thank you Anatolij for you help.

 

Some of text is maybe in natural language but guys from Poland and from other countries will understeand I hope ;)

 

Performance (engines MiG-29) maximal performance.

http://www.mzak.cz/lockon/doc/rd33_max.png

Performance RD-33 full afterburner.

http://www.mzak.cz/lockon/doc/rd33_pf.png

Performance AL-31F (engines Su-27),

http://www.mzak.cz/lockon/doc/al31f_vykon.png

Maneuvring capabilities Su-27 vs. F-15, F-16, Tornado F2

http://www.mzak.cz/lockon/doc/su27_manevrovani.zip

 

EKRAN:

 

http://www.mzak.cz/files/ekran.zip

 

Mig-21

 

Script for testing of performance in lockon.

http://62.168.117.7/letka/SVK_Raimir/Skripty/rychlost.zip

 

Some results:

[Kusch]

 

 

Maneuvring capabilities Su-27 vs. F-15, F-16, Tornado F2

 

 

 

GREAT!!! Thanks!!!

[Pilotasso]

Impressive stuff, is ED taking notes? ;)

[Geier]

Oh, great work:thumbup: Rep inbound)))

[Yo-Yo]

And what do you want to see from ED? :)

All this stuff are very old and well known. But I think the last one - Su-27 vs F's and Tornado will be very useful to clear up the Q about F-15 and Su-27 duel especially how much fuel you must place into Su-27 to match its vis-a-vis.

 

And take in account that engines thrust at the diagrams is for testbench. The real thrust is always less because of inlet losses.

[GGTharos]

Yo-Yo, will you guys at some point model difference in thrust due to variable geometry inlets? :)

[Pilotasso]

And what do you want to see from ED? :)

All this stuff are very old and well known. But I think the last one - Su-27 vs F's and Tornado will be very useful to clear up the Q about F-15 and Su-27 duel especially how much fuel you must place into Su-27 to match its vis-a-vis.

 

And take in account that engines thrust at the diagrams is for testbench. The real thrust is always less because of inlet losses.

 

I would also take note of the F-16 version in there (block 5/10?). Later blocks may have gained some weight but they also got much more potent engines. But all in all In not too surprised about the Su-27's climb rate and turn rate. But I would also like to know how western figures were obtained.

 

The tornado gets smashed badly though. About the engines testbed perfomance, you may get losses in the real aircraft intakes but static tests also feeds less mass into the inlet. I expect real thrust to be signifantly higher with aircraft speed.

[britgliderpilot]

Yo-Yo, will you guys at some point model difference in thrust due to variable geometry inlets? :)

 

Is that not done already?

 

AFAIK, FC's engine data comes from interpolating between data points - whether those points are arrived at from known values or theoretical models I don't know.

 

If the thrust is from known values (as long as they vary with Mach number as well as throttle position/altitude) it's irrelevant.

 

If it's from a theoretical model, then one of two things is probably true:

 

- Mach-variable intake efficiency is not applied to the model. This would mean you'd get more thrust than in RL . . . which by popular consensus seems to be untrue. Plus it seems an oversimplification - a couple of hours in Excel could probably build a halfway accurate model, still accounting for intake efficiency.

 

- Mach-variable intake efficiency is applied to the model. But while there's a fairly big difference between no intake efficiency, normal shockwave intake efficiency, and VG intake efficiency . . . . there's not much difference in complexity between the intake efficiency models. I can't see why a VG model wouldn't be used.

[GGTharos]

A large discrepancy between the real F-15 thrust and the one modeled in LO has been shown - this pertains to medium and high altitudes.

[Pilotasso]

Shouldnt be hard to fix it. Most LOMAC patches have tweaked the FM's.

[britgliderpilot]

A large discrepancy between the real F-15 thrust and the one modeled in LO has been shown - this pertains to medium and high altitudes.

 

Yeah - it's been proven inaccurate, new data accepted, and put on the list for the next fix.

 

But I don't believe that's caused by leaving VG intakes out of the calculation ;)

[GGTharos]

You're probably right, it isn't necessary if your FM is based on performance charts. The problem takes care of itself. :D

[Perry]

And take in account that engines thrust at the diagrams is for testbench. The real thrust is always less because of inlet losses.

 

The real thrust of an engine at a given altitude is always lower than the thrust on the testbench ???

 

Can it happen that the extremely fast airflow that enters the engine in real conditions allows the engine to give better performances than at altitude 0.

 

Sorry if it is a stupid question...

[S77th-GOYA]

Yes, but benchtest figures aren't normally published for the lower density atmosphere that occurs at altitude.

[RvETito]

It depends on the design and the purpose of the engine- for example the R-15 that powers the MiG-25 has only 5-stage compressor and about 75% of the air compression is done by the engine intake, hence the Mach 3 ability. Same goes for the SR-71- they are almost a ramjets- the compressor only serve them to take-off and land. Modern fighters don't fly so fast and their low by-pass ratio engines are optimized for transonic speed where most of the fight occurs. So intake air compression is not so significant.

[amalahama]

Is that not done already?

 

AFAIK, FC's engine data comes from interpolating between data points - whether those points are arrived at from known values or theoretical models I don't know.

 

If the thrust is from known values (as long as they vary with Mach number as well as throttle position/altitude) it's irrelevant.

 

If it's from a theoretical model, then one of two things is probably true:

 

- Mach-variable intake efficiency is not applied to the model. This would mean you'd get more thrust than in RL . . . which by popular consensus seems to be untrue. Plus it seems an oversimplification - a couple of hours in Excel could probably build a halfway accurate model, still accounting for intake efficiency.

 

- Mach-variable intake efficiency is applied to the model. But while there's a fairly big difference between no intake efficiency, normal shockwave intake efficiency, and VG intake efficiency . . . . there's not much difference in complexity between the intake efficiency models. I can't see why a VG model wouldn't be used.

 

Well said, Britgliderpilot!:thumbup:

 

Regards!!

[4c Hajduk Veljko]

REAL PERFORMANCE of RD-33 and much more...

RD-33 engines on MiG-29, piloted by Roman Taskaev, on April 26 1995, propelled that MiG-29 to the height of 27,460 meters (90,092 feet). Some 15,000 feet higher than what SR-71 did on July 28, 1976.

 

Those RD-33’s are some engines!

[D-Scythe]

RD-33 engines on MiG-29, piloted by Roman Taskaev, on April 26 1995, propelled that MiG-29 to the height of 27,460 meters (90,092 feet). Some 15,000 feet higher than what SR-71 did on July 28, 1976.

 

Those RD-33’s are some engines!

 

Um, that's not saying much. It doesn't take much to propel a fighter above the cruise altitude of an SR-71 - virtually all fighters can (ballistically) propel themselves above that.

[4c Hajduk Veljko]

Um, that's not saying much.

Oh, yeah? Setting records does not say much?

 

It doesn't take much to propel a fighter above the cruise altitude of an SR-71 - virtually all fighters can (ballistically) propel themselves above that.

All it takes is RD-33 engine(s) on MiG-29. Well, MiG25/31 (Ye-155M research airplane) can do it as well. It flew little higher to 37,650 meters (123,524 feet). You tell us what year that was?

[GGTharos]

What record? The F-15 streak flew higher than the MiG before the MiG even came to be. The F-15E flying clean beats the F-15 streak in that, too.

 

So ... what exactly was it that was so impressive about the altitude the MiG-29 reached?

 

By the way, the SR-71 CRUISES at those altitudes. The SR-71 was never meant to set time to climb or max altitude records. The MiG did nothing special in comparison with the SR-71.

[4c Hajduk Veljko]

What record? The F-15...

This thread is about RD-33 engines and I am please asking you and other members of the forum to open new threads if you want to talk about F-15 or any other airplanes.

 

RD-33 engines went into history for setting the altitude record in a class of none-payload, turbojet, land-based aircraft weighing between 12,000kg and 16,000kg. Those are the facts. Here's more info:

 

http://records.fai.org/documents.asp?from=general_aviation&id=2554

[nscode]

Some pictures of testing RD-33 on Serbian 29s, before the major repair that should see them airborn starting of December.

Pictures by Mixelotti @ mycity.co.yu forum

 

 

 

 

AND... the effect it has on the grass :)

 

 

http://community.webshots.com/album/557850900ZkVxvO

[SVK_Fox]

[RvETito]

RD-33 engines on MiG-29, piloted by Roman Taskaev, on April 26 1995, propelled that MiG-29 to the height of 27,460 meters (90,092 feet). Some 15,000 feet higher than what SR-71 did on July 28, 1976.

 

Those RD-33’s are some engines!

 

By-pass engines are not that good in high altitude compared to turbojets. Their power is limited due to fan overspeed, so I wouldn't pay attiention to that 'record' of the MiG-29- being much lighter and with much bigger t/w ratio that the MiG-25 how come it can reach balistic ceiling 10km less. Hell even the MiG-23MLD has much better performance above 18000m than the 29.

 

What record? The F-15 streak flew higher than the MiG before the MiG even came to be. The F-15E flying clean beats the F-15 streak in that, too.

 

I believe the purpose of the F-15 Streak Eagle has been to set climb rate records, not altitude. As we all know, all of the Streak Eagle records have been broken by the P-42 (Su-27P prototype). The E-266 (MiG-25) is the one that has been intended to set altitude records and the 37650m for gas-turbine propelled planes remains unbeaten 30+ years. That is the MiG that you should have compared the SE to ;)

 

By the way, the SR-71 CRUISES at those altitudes. The SR-71 was never meant to set time to climb or max altitude records. The MiG did nothing special in comparison with the SR-71.

 

Again, wrong MiG to compare ;) The 25 cruises easily at 23-25km, the 31 goes up to 20-22km.

 

http://records.fai.org/documents.asp?from=general_aviation&id=2554

 

Hmm, that's in the same class as the P-42.. which has set it's records in the 13600kg class (along with it's tuned AL-31F engines that provides TWR of almost 2.0!!!). So that means that this has been a stock 29, with TWR of 1.1. It could have been modified to compete in lower weight class.

[Pilotasso]

What defines maximum operational altitude are not necessarily the engines, but the cockpit pressure and other air activated mechanisms such as life support. Thats why when you use space suits on a fighter, usualy is possible to lower the pits pressure so that is structuraly sane to bring the planes to altitudes close to 100000 feet.