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Eurofighter Typhoon v/s Dassault Rafale - Analysis

Discussion in 'Indian Air Force' started by jagjitnatt, Apr 29, 2011.

?

which aircraft do you prefer

  1. RAFALE

    177 vote(s)
    54.1%
  2. TYPHOON

    150 vote(s)
    45.9%
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  1. Scorpion82

    Scorpion82 Captain FULL MEMBER

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    Thanks. I remember that I read that somewhere, I just didn't know where exactly.
     
  2. G777

    G777 Lt. Colonel ELITE MEMBER

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    Does the Captor-M have more range than the RBE2?? I think it does, just that the RBE2 can detect more targets. Though I think thats because the targets are easier to detect because they are closer.
     
  3. littlejohn

    littlejohn 2nd Lieutant FULL MEMBER

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    I was just curious...
    assuming:
    (i) corner speed = 360kt
    (ii) lift is proportional to AoA
    (iii) lift is also proportional to V^2
    Then the angle of attack required for this Rafale to pull 10.3G at corner speed would be:
    AoA = 13deg*(440/360)^2 = 19,4deg
    (quick and dirty calc...)
    Does that looks sensible?

    C'est quoi le forum A-D?

    ok
    J'aurais quand meme pense que les efforts de flexion vus par le fuselage derriere les plans canard ne sont surement pas anodins et que la structure dans cette zone aurait donc un certain potentiel pour reprendre pas mal de torsion, mais bon...
    L'autre probleme aussi a mon avis c'est que typiquement les canards sont non seulement petits mais aussi relativement proche de l'axe longi de l'avion (donc un faible bras de levier en roulis), donc elles ne doivent pas etre tres efficaces en roulis... (a moins de les braquer outre mesure?)
    ref. la taille et l'envergure des gouvernes de profondeur des F14 et F18...

    Est-ce que cela veut dire qu'il est prevu de faire fonctioner les plans canard du Typhoon en differentiel dans une future modif?

    I keep wondering: the sort of leading edge extension which expends almost up to the air intake inlet, is it a vortex generator device or is it some kind of stealth feature (a bit like the sharp edges either side of the fuselage of the F22, F35, Su-T50,...etc)?
     
  4. Dare2

    Dare2 Captain SENIOR MEMBER

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    AdlA and Marine Nationale were never bothered about RBE2 "Maximum" range, instead the "cahier de charge" focused on size, weight, volume, resistance to EMP, resistance to shock during Carrier Operations and overal capabilities, requiered range was the equivalemnt to that of the RDY and the radar achieved all its requiered specs.


    Just demonstrate how little you comprehend the subject, Captor is a mecanichaly scanned radar, not an PESA or AESA radar and cannot scan nor direct beams like one.

    As for RBE2 PESA it has enough range to allow a Rafale to detect a Typhoon before the opposite happens.
     
  5. Dare2

    Dare2 Captain SENIOR MEMBER

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    This is only valid if you ommit the full structural limit, the Corner speed is based on Operational Structural load, not the FCS maxima and in this form is identical to that of Typhoon, according to Tarnished, a RAF Typhoon Demo pilot who writes in Pprune.

    Although i still have to dig in my archives i know for a fact that a Rafale with two MICAs (or aerodynamically "Clean" if you prefer) would still accelerate at 9.0 g/360 kt and by memory <> 15.000 ft (could be higher i have to memorise this bit).

    Something else you have to take Air Density into account and the characteristics at AoA of the close-coupled canard (See the Mirage IIIS polar), the surface of canard on Rafale is proportionaly larger...

    Plus this is a simplification of Rafale aerodynamics there are other factors less advocated...

    Air Defense; i though you were a member, i don't go there for personal reasons, but there are a couple of active AdlA members there who knows their ABC, such as Pascal and OPIT/DEFA, though not one member really cuts it with aerodynamics.


    Pas en torsion, ca n'est pas la meme chose que l'axe vertical (tanguage).


    Dans le cas des canard integres le but est d'augmenter l'efficacite de l'aile en energisant les vortexes qu'elle genere, c'est surtout le cas sur les IIIS/NG, dans le cas du Rafale on a augmente ce bras de levier en utilisant les vortexes de racine des LEX qui eux, energisent ceux des ailes. (Bon je sais mon Francais me laisse tomber)...

    Normalement une aile delta genere sa portance a sa racine, c'est aussi le cas des LEX donc sur certain deltas on a un regime a un vortex ou plus, comme les double delta ou gothique (concorde).

    En utilisat les LEX, Dassault ont resolu un probleme, le passage assymetrique du point de portance en superspnique (qui depend de l'angle de fleche) de devant le Cg a derriere, et passe du regime vortexe singulier au multiple.
    [​IMG]
    [​IMG]
    Peinture sensible à la pression - Onera
    [​IMG]
    Décollement en écoulement 3D. Points singuliers, lignes séparatrices et tourbillons - cours de Jean Délery - Onera
    [​IMG]
    [​IMG]
    Eclatement tourbillonaire sur une aile delta en incidence - Images de science - Onera
    [​IMG]
    Développements de tourbillons au dessus d'une aile delta en tunnel hydrodynamique - Images de science - Onera
    [​IMG]
    Développement d'un tourbillon au dessus de l'un des bords d'attaque d'une aile delta - Images de science - Onera




    Je ne le pense pas, ils ont toujours eu un probleme avec leur devis de poid, meme en reduisant la charge structurelle maximum a 1.4, depuis, Eurofighter on du renforcer la cellule a partir de la version T2 afin de lui permetre de remplir des missions "multiroles".

    Note qu'on n'a toujours pas de nouveau poid a vide indique pour cette version...


    Of course a vortex generator, and a really efficient one, on this surface you have at least two different sources of vortexes, the LEX root, the LEX/Wing junction, the F-22 have EXACTLY the same leading edge planform with 48* Sweep angle and <> 70* sweep LEX.
     
    Last edited: Jan 29, 2012
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  6. littlejohn

    littlejohn 2nd Lieutant FULL MEMBER

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    I must admit I am confused now, if the airframe is able to withstand 10.3G at 440kt (as per HUD indication), why wouldn't it be able to withstand the same acceleration (10.3G) at 360kt?
     
  7. Dare2

    Dare2 Captain SENIOR MEMBER

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    I meant the opposite, the corner speed is lower/higher (got to look at my chart) than it is in reality if you take the Maximum allowed by the FCS and not the operational 9.0 g limit, it would be able to pull that many g at 360 kt or perhaps lower anyway.

    What it means is that it is not correct because it doesn't take the maximum Structural load into account, it is computed 3.0 g lower.

    [​IMG]
    From this it look as you were correct in your questioning, the corner speed is the lowest speed at which it can pull the maximum g.

    I forgot, at this speed Rafale would still accelerate, meaning it can pull more than 9.0 g even higher up (depending on Air density up to 11.0 g).
     
    Last edited: Jan 29, 2012
  8. Dare2

    Dare2 Captain SENIOR MEMBER

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    Irrelevant to this topic but quiet informative.

    Note the twist of phrasing when Burbage talks about loading, what he doesn't tell is that F-16 (LWF) combat configuration was computed for 50% internal fuel and 2 X AIM-9s while it is the same for the "eurocanards" wit hinternal fuel, their AAM loading is way higher as well as pylons and AAMs flight and firing envelops.

    Calling for a similar fuel load for US legacy fighters to compare with is totally unfair and comparing to Typhoon or Rafale in combat configuration would leave the F-35 dead in the coldm, especially in transonic/high transonic where the delta have a much lower drag ratio.

    (*) The bottom line being: Cross section is a factor in drag wave, to reduce it there are aerodynamic solutions, such as mid-fuselage mounted wings and large bending areas. Guess which aircraft is designed for these particular characteristics?

    (**) In the same configuration, misleading the reader into thinking they were designed around the same specifications.


    (***)That's also misleading what he means is in A2A configuration, in A2G configuration it would be g limited like the rest of them...

    (****) Same here, in its original combat configuration a F-16 would out-drag, out-accelerate and out-fly an F-35 in the same confirutaion, 2 X AIM-9 and 50% internal fuel.

    Good example here of commercials spinning...
     
    Last edited: Jan 29, 2012
  9. smestarz

    smestarz Lt. Colonel REGISTERED

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    Guess the source is ANTONIA.
     
  10. JWCook

    JWCook FULL MEMBER

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    Yes..

    for those that are interested here' s a walk round of the Typhoon with close up pictures showing the build fit and finish.

    Typhoon walk round

    Cheers
     
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  11. Mr_Breaker

    Mr_Breaker Lieutenant FULL MEMBER

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  12. G777

    G777 Lt. Colonel ELITE MEMBER

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    Please can I add these in the Eurofighter section :angel:
     
  13. G777

    G777 Lt. Colonel ELITE MEMBER

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  14. arulcharles

    arulcharles Lieutenant FULL MEMBER

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    Hi Dare2
    could u please explain this video. It is not in English
     
  15. littlejohn

    littlejohn 2nd Lieutant FULL MEMBER

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    Sorry to keep asking questions but I am just keen to make these things clear in my mind, as this seems to differ quite a bit compared to civil aviation which I am more familiar with:
    if I understand what you are saying, there are three things:

    1) operational load limit which
    in case of the Rafale would be 9G in clean.
    This is the "normal utilisation of the aircraft" limit.
    This is the load at which the corner speed is given (360kt in case of the Rafale).
    2) Limit load which:
    isn't necessarily the operational load limit and everything suggests that Rafale's would actually be around 11G in clean.
    Up to 11G for the Rafale, it is basically guarantied that they won't be any permanent deformation of the airframe.
    The FCS protects against any exceedence of this boundary.
    3) Ultimate Load which is obviously 1.5LL (well actually 1.4 on Typhoon but that's an exception).


    [​IMG]

    I personnaly prefer Turn Rate vs Speed diagrams as I personaly think they tell a bit more, but from looking at this graph above, the parabolic curve boundary (for speed range 0-200) is the boundary where Cl is at its maximum isn't? which means AoA maximum, which in case of the Rafale would mean AoA ~ 30deg when flying on this boundary curve?

    I am asking because from the (440 kt, 13*A0A, 10.3 g) figure you supplied in post 8843, the equivalent angle of attack at 9G for the same speed would be:
    AoA = (9g/10,3g) * 13deg = 11.4deg (for 440 kt at 9g)
    From which we get the following AoA at 360kt (corner speed) and 9g:
    AoA = (440kt / 360kt)^2 * 11.4deg = 17,0deg (for 360 kt at 9g)

    This is way off the 30deg limit that I would "theoritically" expect at the intersection between the max Cl boundary and the max G boundary (corner speed point). I must have skrewed up but I don't know where...
    Or maybe there is another explanation.

    I am with you on that one.


    Are you 100% sure?
    I found that statement here below:
    "Rebourg said that with a clean Rafale, using afterburner, you can enter a turn at 500 kt. and 10,000 ft., pull the maximum 9g and still accelerate. Cornering speed for the Rafale is 360 kt., he said."
    I don't seem to find the original internet link anymore but I saved the actual text on my HD...

    a+
     
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