Rafale RB of Indian Air Force : News and Discussions

Optimist

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I'd quit while you are behind. The F-35 would be 26,500 lb of fuel with 4x 2,000 lb and missiles. Most would also have A2A refueling available.

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Lolwa

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You may be looking at old charts. Early blocks were limited to less than M1.6 As testing went on. The envelope increased to M1.6
View attachment 21803
Envelope can obviously be increased but most planes operate in 1.2-1.4 Mach regime it seems even the high speed air superiority fighters like the f-15 because of engine wear and tear.
 

Optimist

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Envelope can obviously be increased but most planes operate in 1.2-1.4 Mach regime it seems even the high speed air superiority fighters like the f-15 because of engine wear and tear.
Agreed. Mostly the f-35 will be subsonic, rarely going supersonic and seldom M1.6. Most likely, a flight test after maintenance. Although they say the F-35 is M1.2 without AB, I don't know how valuable that will be. You are air friction, heating the frame and open to other IR sensors.
 
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randomradio

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Agreed. Mostly the f-35 will be subsonic, rarely going supersonic and seldom M1.6. Most likely, a flight test after maintenance. Although they say the F-35 is M1.2 without AB, I don't know how valuable that will be. You are air friction, heating the frame and open to other IR sensors.

It's not mach 1.2 without AB, what it does is use the afterburner to cross the transonic regime, switches off its AB and then cruises at mach 1.2 for merely 150Km. Real supercruise requires you to cross the transonic regime without AB, and maintain a high speed enough to be tactically relevant. For example, the Su-57 is being made to supercruise above mach 1.5 for 1500Km. The F-35's so-called supercruise is totally irrelevant and even the guy says that.
 

Innominate

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It seems like most modern day fighters are limited to mach 1.6. The F-35 seem to be limited at mach 1.2-1.4
Even the f-15 mach 2.5 number is rarely used.
Wrong. F-35A/B/C top speed is mach 1.6 with a full internal AG load. F-35C anf F-35B pilots have been told not to exceed mach 1.3 for F-35C and mach 1.2 for F-35B because of peeling of coating that only happened one to those two fighters when they were being flown to extreme edges of their envelope at 50k and mach 1.6. They tried replicating it but the coating did not peel off when thy tried numerous times so they ordered pilots not to exceed those speed for a certain amount of time... during peacetime of course.

The french plane top speed of mach 1.8 is without a combat load.
 

Innominate

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Rafale A has made Mach 2 using only one engine... Official G limit is 9G and the plane is able to go up to 11.5 G with structural limit at 16G...
The way we use it allow us to increase it service life from 7500 h to 9000 h and it will probably exceed 12000 h when we will be able to better study how it has aged. It's why we limit it during peace and crise time, but not during war time, if needed.

' That "Mach 2 speed" was achieved by a Rafale PROTOTYPE which was quite different from the production aircraft and hence why currently the Rafale top speed is Mach 1.8 which concurs with the also stated 750 knots (if this speed is CAS) at an altitude of 33,000 ft.' :sneaky:
 

Innominate

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By the way, the picture showing a 760 Nm combat radius for F-35 in for an Air to Air internal configuration, so it has to be compared with the picture where the Rafale is with an air superiority configuration and a combat radius of 920 Nm with two more missile compare to F-35.

That supposed radius for the french plane is at optimum altitude in a straight line since it will be a flying brick with all those tanks and weapons hanging but we all know the french plane having a big RCS will not be able to fly at those altitudes or straight line it will be flying at low altitude in really dense air to avoid radar making it a draggier flying brick cutting its radius severely.

You should know this since you like telling everyone in here what a smart man you are, right?
It's not mach 1.2 without AB, what it does is use the afterburner to cross the transonic regime, switches off its AB and then cruises at mach 1.2 for merely 150Km. Real supercruise requires you to cross the transonic regime without AB, and maintain a high speed enough to be tactically relevant. For example, the Su-57 is being made to supercruise above mach 1.5 for 1500Km. The F-35's so-called supercruise is totally irrelevant and even the guy says that.
The F-35, while not technically a "supercruising" aircraft, can maintain Mach 1.2 for a dash of 150 miles without using fuel-gulping afterburners.

"Mach 1.2 is a good speed for you, according to the pilots," O’Bryan said.

The high speed also allows the F-35 to impart more energy to a weapon such as a bomb or missile, meaning the aircraft will be able to "throw" such munitions farther than they could go on their own energy alone.

There is a major extension of the fighter’s range if speed is kept around Mach .9, O’Bryan went on, but he asserted that F-35 transonic performance is exceptional and goes "through the [Mach 1] number fairly easily." The transonic area is "where you really operate."

In combat configuration, the F-35’s range exceeds that of fourth generation fighters by 25 percent. These are Air Force figures, O’Bryan noted. "We’re comparing [the F-35] to [the] ‘best of’ fourth gen" fighters. The F-35 "compares favorably in any area of the envelope," he asserted.
 

Picdelamirand-oil

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You are too stupid and in too much bad faith for me to teach you how to calculate the range of the Rafale and that of the F-35 and why the Rafale is always capable of reaching Mach 1.8 whatever the weight of its under-wing payload unless one of these payloads is itself limited to a lower speed.
 
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Innominate

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You are too stupid and in too much bad faith for me to teach you how to calculate the range of the Rafale and that of the F-35 and why the Rafale is always capable of reaching Mach 1.8 whatever the weight of its under-wing payload unless one of these payloads is itself limited to a lower speed.
Lol. Or could it be you're so full of shit you can't convince anyone of your bull shit? Duhssault is clear the french plane (clean config) top speed is mach 1.8 which means when you start hanging missiles and tanks it's much slower. french plane M (clean config) top speed is mach 1.6 meaning it's slower with tanks and missiles. Don't get salty and uppity that your plane is heavy and underpowered (According to Safran CEO)

F-35 top speed is mach 1.6 with or without a full internal AG load.
 

Picdelamirand-oil

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I'd quit while you are behind. The F-35 would be 26,500 lb of fuel with 4x 2,000 lb and missiles. Most would also have A2A refueling available.

View attachment 21805
The maximum ordnance capacity is 18,000 lbs and the sum of the ordnance weights shown on this graph is 22,300 lbs, so we will have to remove 4,300 lbs from the description of what the F-35 can carry.
As the aim is to demonstrate that the F-35 has more range than the Rafale, we cannot remove fuel. You can't take out the air-to-air missiles either, because they are not profitable for the imagination and are too light to fulfill the contract. You can't take out the cannon either, because it's integrated into the structure, so you have to take out two bombs.

The description therefore becomes "The F-35 would be 26,500 lb of fuel with 2x 2,000 lb and missiles", which is what is usually written.

It should be noted that the F-35 also loses its stealth with this load and is therefore inferior in all areas to the Rafale.
We will now be able to calculate whether this sacrifice at least allows it to have a better range.
 

Optimist

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The maximum ordnance capacity is 18,000 lbs and the sum of the ordnance weights shown on this graph is 22,300 lbs, so we will have to remove 4,300 lbs from the description of what the F-35 can carry.
As the aim is to demonstrate that the F-35 has more range than the Rafale, we cannot remove fuel. You can't take out the air-to-air missiles either, because they are not profitable for the imagination and are too light to fulfill the contract. You can't take out the cannon either, because it's integrated into the structure, so you have to take out two bombs.

The description therefore becomes "The F-35 would be 26,500 lb of fuel with 2x 2,000 lb and missiles", which is what is usually written.

It should be noted that the F-35 also loses its stealth with this load and is therefore inferior in all areas to the Rafale.
We will now be able to calculate whether this sacrifice at least allows it to have a better range.
Yes, by all means do a comparison of the Rafale and the F-35 with 2x 2,000lb, let me know how it goes.
 

Picdelamirand-oil

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It is late: I have prepared the evaluation and will clean it up tomorrow.
Well, let's go step by step and first some explanations on the method:

Range is a complex issue: it depends on the mission profile, the aerodynamics of the aircraft, the specific consumption of the engines, but also on the way to use drop tank: in peacetime, you don't drop your tank but in wartime, in a contested airspace, you certainly drop it to reduce the RCS and increase the range.

So the range of the ferry? Is that with the tank dropped or not? The approach of adding to the range every time you add a dropped tank seems valid to me. But if you were to do a simple rule of three to calculate the increase in range you can expect each time you add a tank, you would find that a 2000 l drop tank adds 617 km of range to a Rafale. But this is not true.

A rough way to calculate the range is to say that it takes one drop tank to carry the other because of drag!

I can calculate an example to show you the use of this rule.

Let's suppose that the Rafale has a range of 3700 km without dropping a tank. We have the Rafale, with 3 drop tanks of 2000l which is able to fly 3700km.

The rule I gave says that the "yield" of the jettisonable tank is only 50% of the internal fuel, so everything happens as if the Rafale had 3000 l extra internal fuel: with 5750l +3000l its autonomy is 3700 km so with only 5750 l internal fuel its autonomy will be: 3700*5750/8750= 2430 km and each drop tank only adds 424 km.

Now, if the 3700 km is done with the dropped tank, the "efficiency" is about 75%, the range with internal fuel is then 2075 and each drop tank adds 541 km. But for a ferry mission there is no contested airspace to cross so the former is likely.
 
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Picdelamirand-oil

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Now how to take into account weapons? I can just propose an approach.

Normally drag increase with the volume and a first approximation could be that a weapon and a drop tank drag the same if they are of same volume. But density of fuel is 0.81 so density of a drop tank is close to 1. For a weapon density is certainly bigger. The aerodynamic is also different. Unfortunatly we don't have acces to these data. The idea is to estimate a pseudo density which take into account the real density and aerodynamique.

Suppose a weapon load of 4 MICA + Talios pod + 6 GBU-12 bombs It should weigh about 2108 kg. Suppose that the pseudo density for this weapon load is 3. The drag will be the same as a drop tank of 700 kg which would carry 700l of fuel. So now your Rafale have only 5050 l internal fuel and 700l on drop tank. If the weapons are not used the efficiency is 50% and the range of Rafale is as if it only have 5400 l of fuel and if weapons are dropped the efficiency is 75%. Now the pod and some air to air missile are perhaps not dropped!

The difficulty is to estimate the pseudo density. The only way is to reverse ingeneering data given by manufacturer. A Scalp or a Storm Shadow will have the same pseudo density for a Typhoon or for a Rafale. And an Amraam or a Mica would be very close.
 

Picdelamirand-oil

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The method I gave is approximate, the real method uses drag indexes, an explanation of this method is given here:
View topic - Drag index calculation - F-16 Armament & Stores
It is followed by some data on the A-10, F-15 and F-16 and an example that concerns the F-16 and the reference area (300ft^2) referred to is the wing area as is traditionally the case.
For the Rafale this area is 492 ft^2.

To calculate the drag index of the Rafale we can use the same conditions as the example, so we need the drag of the Rafale smooth at M 0.8 at sea level. This drag will be balanced by the thrust of the engines, which consume 44 kg of fuel per minute in these conditions, i.e. 2640 kg per hour.
As at this speed no afterburner is used, the specific consumption is 0.80 kg/daN-h which gives a thrust of 3300 daN or 7425 lbf.

From there the explanations are enough to calculate everything, but we have no data for the pylons.

We can for example calculate the drag index of the Rafale:
Rafale's reference area S: 492 sq. ft^2.

Drag D of the Rafale smooth at 0.8 mach, at sea level: 7425 pounds.
D = Cd * q * S
Cd = D / q*S
q at .8 sea level is 947 lb/ sq ft
S = 492 sq ft^2
so Cd = 0.0159

Basic airplane drag index: 159
 
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Picdelamirand-oil

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Calculation of the drag index of a certain load for Rafale:

Cd (F-16) = Cd x (load surface cross section / 300 sq ft)
Cd (Rafale) = Cd x (load surface cross section / 492 sq ft) = Cd (F-16)* 300/492
  • Cd (F-16) GBU 12 = 7
  • Cd (F-16) GBU 24 = 20
  • Cd (F-16) MK 84 = 9 (+15 adapter)
  • Cd (F-16) AIM-9L =5 (+6 adapter)
Which imply
  • Cd (Rafale) GBU 12 = 7* 300/492 = 4.27
  • Cd (Rafale) GBU 24 = 20* 300/492 = 12.2
  • Cd (Rafale) MK 84 = 9 (+15 adapter) * 300/492 = 5.5 (+ 9.14)
  • Cd (Rafale) AIM-9L = 5 (+6 adapter) * 300/492 = 3 (+ 3.66)
 

Picdelamirand-oil

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Calculation of the drag index of a tank for the Rafale

We consider a smooth Rafale

Its range with full fuel is noted X in km and full fuel is noted Y in litre

The consumption to cover 1km is therefore Z=Y/X

We now consider a Rafale with two tanks each containing y litres of fuel.

According to the rule that it takes one tank to carry the other its range will be (Y+y)/Z and the consumption for 1 km will be Z1 = (Y+2y)/((Y+y)/Z).

The increase of the drag index is therefore 159*((Z1/Z)-1)

Now Z1/Z= (Y+2y)/(Y+y) = 1 + y/(Y+y) and therefore the drag index increase is 159*y/(Y+y).

As the rafale can carry 5750 l internally this gives:

For a 2000 l tank: 159*2000/7750 = 41

For a 1250 l tank: 159*1250/7000 = 28.4
 
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