[Renamed] M88-2 not compromising the IR signature of Rafale

Bluewings · **Joined:** Wed May 20, 2009 12:02 am **Posts:** 3

Why did you say , I quote :
""In most situation, the M88-2 doesn't even compromise the IR signature of the Rafale !""

and then locked the thread ? :shock:

The Rafale has indded a lower IR signature than the SH because of : (1) less engine power , (2) better heat repartition design design , (3) better internal and external cooling but the Rafale IR signature is compromised -as any other aircraft .
The main heat source for any adverse IRST or IR seeker is still the engine , TMor .

A+

Bluewings · **Joined:** Wed May 20, 2009 12:02 am **Posts:** 3

Maybe we should look into an electrical Glider capable of Mach 1.8 with (?) power cells also capable to run the whole aircraft (radar , FCS , Spectra , etc ...)
This is not for 2moro

A+

TMor · **Posted:** Sun May 31, 2009 10:32 pm

Hi Bluewings,

That's a good question : my articles are a translation of my website. This website is made of everything i could find on the Rafale...

Now, i'll quote Fox Three n°2 :

Quote:

Additionally, the M88 has been optimised so that its small infrared signature does not compromise the Rafale’s overall IR signature.

I decided to add "in most situation" because i doubt that with full AB, the Rafale won't look like a christmass tree. :lol:

Do not hesitate to ask about my sources... I still have my original text file in which i had quoted everything.

PS : i locked the topic so as to keep it as clean as possible. I may change the formula later.

Wingman · **Joined:** Tue Jun 02, 2009 11:00 am **Posts:** 149

Rafale IR signature is hardly compromised by the actual M-88, I can remember reading comments from F-18 and Harrier pilots (USN and Spanish Navy) in some magazine, saying they were struggling to get an IR lock on them even when they were in full AB.

The design of the M-88 con-di nozzles is meant to reduce the angle at which the IR signature is strong enough to insure a good lock; this is why the external petals are prominent and also the reason for an additional cooling channel.

Dassault and SNECMA (now Safran) have been working on an even lower IR signature since the M-88 3 program, a TVC was even designed (although the progresses in design points were not specified).

So it is fair to say that among most fighters, Rafale is the one with the lowest IR signature perhaps to the exception of F-22, mainly due to the design of its TVC nozzles.

I explained (awaiting the usual commentaries) in a few different forums the whole thing which I have documented for quiet some time with explanations from the Rafale program manager of the time and a few good illustrations...

So before we get all exited, the IR plume in the middle of the fuselage doesn't show in Serie Rafales, it was exhausting from the Avionic Bay and the source was threaded as part of the signature reduction fine tuning work done on the aircraft during development.

This one comes from ONERA which was the main SNECMA partner in this work for signature management, one can see the difference in temperatures between the internal nozzles and the external.

Salut la Chasse!

TMor · **Posted:** Tue Jun 02, 2009 5:37 pm

I appreciate your contribution, sir, but can you edit your message so as to add links to back up some claims ?

Wingman · **Joined:** Tue Jun 02, 2009 11:00 am **Posts:** 149

TMor wrote:

but can you edit your message so as to add links to back up some claims ?

When i got links i post them and i am looking for some perticularly on the M88-3.

I have been looking for the articles in question (Rafale first deployement in Af'stan) in F-I but the main one was most certainly an AFM article; no way to back this up (they dont have archives with full articles like F-I) appart getting the magazine and scanning.

I used to do just that before my scanner died, but Q: Which part of it needs to be backed up? My telephonic conversation with some programe manager at Dassault?

Please be specific.

Thanks.

TMor · **Posted:** Tue Jun 02, 2009 5:53 pm

Ok.

So, it all depends on either we trust you or not (i mean : for the claims not backed up).

Though i understand how frustrating it can be, I hope you're ready to see people not agreing with you.

I have proposed some suggestions :
suggestions-t4.html
You may use it or not.

Wingman · **Joined:** Tue Jun 02, 2009 11:00 am **Posts:** 149

Quote:

The M88-3 is a derivative of the M88, now in production for the initial batch of Dassault Rafale fighters.

The M88-3 thrust growth comes from a new low-pressure compressor now under development, and the engine will also include a new nozzle designed to reduce exhaust signature. DATE:02/08/95
SOURCE:Flight International
Snecma

Archive.

Well i'm not the AJ i name my sources but i'm not prepared to get a back copy just for the stake of making this point although i am planning to do just that for a photo of Rafale M 01 performing a figure i haven't seen any Sukoi or Typhoon do, Hives KerHerve was quiet.... agressive and he was already doing the "Square dance i saw him at Farnborough 95.

It's common sense just to assume that cooling of a hot airflow is helpt by a cold one, same for the surfaces this is what meteorology is all about for example.

In the case of M-88 we can even tell it is a low pressure airflow due to its source and expending channel, smart design, lower pressures helps reducing temperatures further.

Quote:

The M88-3 thrust increase comes from a new, increased-flow, low-pressure compressor now being developed, on which tests began in Snecma's Villaroche plant, near Paris, on 17 February. Technology for the compressor comes from the French CENTOR programme, which incorporates research from the Onera research agency, French universities, and Snecma itself. "The aim is to widen the range of operability," says Masson, "so that the engine is more efficient in intermediate and low-power regimes."

The three stages of the development compressor now in test each feature integrally bladed discs and compressor-discs, known as "blisks". These are lighter than the current units (in which the blades are inserted individually into each disc), while the three dimensional blade design, contributes to the significantly improved performance, namely a higher pressure ratio (4.3 versus 3.8 on the M88-2) and extra airflow (72kg/s versus 65kg/s).

"We don't know at this stage if we will be using blisks throughout the low-pressure compressor", says Massot. "Although we've done a lot of mechanical tests, we have only just begun aerodynamic testing". Much depends on finding the right solution to the blade vibration, which can affect LP compressor blisks in which the blades are relatively long, and there is no natural damping through the movement of the blades in the root. "The trick is to compromise between mechanical strength and aerodynamic performance", says Massot.
DATE:03/05/95
SOURCE:Flight International
Future thrust

If you dont see these in the F-I search engine, they are either PDF archives or part of a "special" in which case the title is that of the special edition, you will have to search by date...

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[Renamed] M88-2 not compromising the IR signature of Rafale

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