F-35 internal fuel, range

Discuss the F-35 Lightning II
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marsavian

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Unread post27 Apr 2019, 00:09

castlebravo wrote:
eloise wrote:
missile range estimation 2.JPG


Where are you getting the missile range estimation graph from? I find it hard to believe that a ramjet missile with the intake sticking out in the breeze is going to decelerate at the same rate as an AIM-120 after the motor is out. I also wonder if they account for intake ram drag when calculating the actual thrust at Mach 5+. If ramjets are that awesome for hypersonic missiles, where are all the Mach 5+ AShCMs, and why is everyone clamoring to build a scramjet missile?


It's a missile simulation.

viewtopic.php?f=44&t=54426

Specifically,

https://jaesan-aero.blogspot.com/2019/0 ... 3.html?m=1
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Unread post27 Apr 2019, 04:13

I can't find any details on how he simulated a VFDR, but I wouldn't be surprised if he just plugged in a higher ISP. Reality is far more complex. Ducted rockets have been used in SAMs since at least the 1960's, and in one case (SA-6/SA-11) we have actually seen an older ducted rocket missile get replaced with a modernized version that uses a plain old solid rocket motor. I suspect the key advantage of Meteor is not higher ISP from it being a ducted rocket, but that it uses a Variable Flow Ducted Rocket that allows it to throttle down when appropriate. Unless the VFDR is actually a form of scramjet where the intake air is not decelerated to subsonic velocity, I just don't see Meteor having 3+ times the performance of AIM-120D in every scenario.

If ducted rockets really were that good, everyone and their mom would be using them for their high-end SAMs, and we would have SM-6 Blk III missiles diving down on targets 500+ nmi away while going Mach 6. In reality, we see the exact opposite. A lot of the oldest SAMs built used air breathing engines, and none of the modern ones do. I call that a clue.
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Unread post27 Apr 2019, 04:59

castlebravo wrote:I can't find any details on how he simulated a VFDR, but I wouldn't be surprised if he just plugged in a higher ISP. Reality is far more complex

http://jaesan-aero.blogspot.com/2019/01 ... on-of.html
https://jaesan-aero.blogspot.com/2019/0 ... on-of.html
http://jaesan-aero.blogspot.com/2018/10 ... art-2.html

castlebravo wrote:I just don't see Meteor having 3+ times the performance of AIM-120D in every scenario.

He put AIM-120C-5 in his graph
Secondly, according to various sources, ramjet missiles can improve range by factors of 3 or more
Image
image_260281.jpg


castlebravo wrote:If ducted rockets really were that good, everyone and their mom would be using them for their high-end SAMs, and we would have SM-6 Blk III missiles diving down on targets 500+ nmi away while going Mach 6. In reality, we see the exact opposite. A lot of the oldest SAMs built used air breathing engines, and none of the modern ones do. I call that a clue.

Solid rocket motor has 2 advantages over ramjet:
- Significantly higher initial acceleration
- Can reach higher altitude because their propulsion don't require air
Surface launched missiles has 2 differences from air-launched missiles
- It is easier to increase their size and weight
- They are more limited by radar horizon.
In short, long range is not as important as acceleration and flight ceiling for SAM, and it is easier to increase their size or add a booster so ramjet is not as important for SAM as they are for AAM.
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Unread post27 Apr 2019, 10:38

sprstdlyscottsmn can also get high range numbers for Meteor with his missile sim with certain assumed parameters.

viewtopic.php?p=414945#p414945
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steve2267

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Unread post27 Apr 2019, 13:47

I won’t argue range, but am astonished the Meteor is a 6+ Mach missile — and a ramjet at that! They really are working miracles with CFD these days.


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Unread post27 Apr 2019, 14:32

Yeah, I got max range at min thrust.
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Unread post28 Apr 2019, 01:25

Salute!

Did I miss the thread topic?

Besides, why use old-fashioned missiles ?

I got my megawatt laser powered by the magnetohydrodynamic grid of the small rocket motor on station 6. You know, the doofer that strips off electrons and ions and generates more power you can dream of when I activate it.

And BTW, there's always an optimum pounds per mile versus miles required in the time available for my plane that uses JP fuel and gets the missile or laser to the fight. My Stubbie has plenty, and it sips gas..

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doge

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Unread post06 Jun 2019, 02:04

F-35 test pilot Tony "Brick" Wilson made remarks that seemed quite important. 8)
From 7:35~

F-35A on station time 2.5 hours.jpg

The F-35A carries about 18,000 lb of fuel internal compared to when I was flying 4th Gen Fighters.

The Legacy F/A-18 carries a little over 10,000 pounds and the Super Hornet carries a little over twelve thousand pounds internal.

Why is this important? Because, with the single engine in that much fuel onboard my on station time is greater.

If I'm flying a max endurance max range type of profile, I'm able to get to two and a half hours of on station time easily out of this aircraft.

"On-station time is 2.5 hours"!! :shock:

I think this is an important number in relation to the mysterious F-35's range (Clear true numbers[km, nmi] not be released. or Classified.) or radius.
I think "2.5 hours on-station time" is very very long. 8) (It's...Long working hours!! :doh: )
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Unread post06 Jun 2019, 02:16

https://www.youtube.com/embed/hmnkcP-sJHk BEST TO USE: https://www.youtube.com/watch?v=hmnkcP-sJHk

LOOKS like '360 degree video' does not work in IE 11 but does in EDGE! so title & link to click on below & the URL works.

360 VIDEO: F-35 Test Pilot Walkaround https://www.youtube.com/watch?v=hmnkcP-sJHk

Without watching video "what does on station time mean"? Where and WHEN does it start from the carrier? Is it overhead?

A4G Skyhawk: www.faaaa.asn.au/spazsinbad-a4g/ & www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/videos?view_as=subscriber
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Dragon029

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Unread post06 Jun 2019, 04:08

It'd be interesting to see what range that'd be at from an airbase; it definitely wouldn't be the combat radius, but would this be doing circuits over an airbase? At a training range 50nmi from an airbase? 100nmi? 200nmi?
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Unread post06 Jun 2019, 05:03

Dragon029 wrote:It'd be interesting to see what range that'd be at from an airbase; it definitely wouldn't be the combat radius, but would this be doing circuits over an airbase? At a training range 50nmi from an airbase? 100nmi? 200nmi?

'Brick' is the FIRST PILOT to arrest aboard a CVN with the F-35C - he was the CO of VX-23 until I guess he retired to be an LM F-35 test pilot. My thinking was 'F-35C from carrier' to be overhead ready to 'buster' out to the bogey but the comment is so NEBULOUS that it becomes irrelevant without context. So we can all 'guess away' to own heart's content. No?

For those unwilling to be '360' here it is in the FLAT EARTH look....

Tony 'Brick' Wilson LM Test Pilot F-35 Explained Walkaround 360 https://www.youtube.com/watch?v=5Xn0asyM_-E

UHoh - not even IE 11 shows the FLAT video now so use the URL.

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doge

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Unread post06 Jun 2019, 09:50

About the "on-station time", I found thing of F-16V. 8) (It looks like the magazine of the Indian Force.)
http://forceindia.net/feature-report/fi ... xcellence/

http://www.vayuaerospace.in/issue/vayu- ... df#page=90
Unparalleled Mission Reach
The F-16 Block 70 with conformal fuel tanks has a mission radius exceeding 1,700 kilometres (km) in an air-to-air configuration carrying four AMRAAMs, two ASRAAMs and two 370 gallon fuel tanks. This yields a 750 km DCA Combat Air Patrol (CAP) with on-station time of more than two hours.

Even with the addition of targeting systems and two 2,000 pound (lb) class Joint Direct Attack Munitions (JDAMs), the F-16 Block 70 has a mission radius exceeding 1,300 km — 30 per cent greater than that of the F-16’s closest competitor. With the optional 300 gallon centreline tank and two 600 gallon wing tanks, the F-16 Block 70’s advantages are even greater.

F-16V [CFT + 370galEFTx2] Total Fuel About 15,000lb-----------This is Roughly(internal 7,000lb + CFT 3,000lb + 370galx2EFT 5,000lb)

The F-16V's DCA/CAP mission, with fuel about 15,000 lbs, it seems have radius is 750km/on-station time is more than 2 hours.
I hope that F-35A is longer than this F-16... (Because, there are more fuel about 3,000lbs than that! :doh: )(desire 8) )
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Unread post06 Jun 2019, 14:03

Did I miss it or did they not provide the radius at which the TOS was calculated? You can take off and orbit home plate and generate boo-coo TOS...
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Unread post06 Jun 2019, 15:51

I just love the fact it carries so much gas.

For so long, even big US fighters seemed short legged. The F-15 for example: 13.000 or so lbs of fuel vs. most Flankers, up to 25,000lbs. I realize they have different needs (huge country, not much in the way of tankers), but simply carrying more gas makes more sense to me.

LM did a really good job with the internal fuel it packed into the F-22, and a GREAT job with the 18,000lbs in the F-35A, I think 13,000 in the B and 19,000 in the C. The pilots sure seem to appreciate it..
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Unread post06 Jun 2019, 16:06

doge wrote:I hope that F-35A is longer than this F-16... (Because, there are more fuel about 3,000lbs than that! :doh: )(desire 8) )
Given that the F-35A has a longer Combat Radius in A2G mode vs an F-16 with CFTs and EFTs (600 gal), the F-35A should also out-range it in A2A, especially considering the F-16 in the above example has 370 gal EFTs.

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