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Posted (edited)

f15c used to have fuel flow rate around 12k per engine at 60k alt, at Match2.0.

same clean config lower fuel to match total load of F15C, the F15E cant even get to Mach 2.0.

- can you post fuel rate curves F15C and F15E at different altitudes 40k 50 55 60, and the TAS speeds 

- F15c used to be possible to cross Tbilisi to Anapa at Mach2, F15e cant get even half way to Sochi without running out of fuel.

Please check!

Thank you

Edited by xrx
Posted (edited)
42 minutes ago, xrx said:

f15c used to have fuel flow rate around 12k per engine at 60k alt, at Match2.0.

same clean config lower fuel to match total load of F15C, the F15E cant even get to Mach 2.0.

- can you post fuel rate curves F15C and F15E at different altitudes 40k 50 55 60, and the TAS speeds 

- F15c used to be possible to cross Tbilisi to Anapa at Mach2, F15e cant get even half way to Sochi without running out of fuel.

Please check!

Thank you

 

C and E are two different airplanes for one.

E and C are two completely different modules in terms of engine modeling for two.

C and E are replicating two different engine types for three.

The C is done by ED, you are more than welcome to do your own fuel flow test and curves for that one.

Based on just those comparisons...as far as I need to go.

Edited by Rainmaker
  • Like 4
Posted
34 minutes ago, Rainmaker said:

C and E are two different airplanes for one.

E and C are two completely different modules in terms of engine modeling for two.

C and E are replicating two different engine types for three.

The C is done by ED, you are more than welcome to do your own fuel flow test and curves for that one.

Based on just those comparisons...as far as I need to go.

 

hold a sec

C and E is same airplane from aerodynamics point of view, it does have the same frame (exclude minor variations second seat etc)

- length/height, wingspan, wing area, wing airfoil model -- according to wiki specs its exactly apples to apples

- engines are dual pratt whitneys f100pw220s exactly same 65 kN dry thrust (newer pw229 has 80kN)

https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15_Eagle

https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15E_Strike_Eagle

only difference is internal fuel tanks, which built for different tasking  - but clean config is exactly same

 

again - at same clean config and total weight it has to fly C and E exactly same, it terms of acceleration, top speed, alt limit

 - it would be interesting to show community reference curves how f15c f15e different airpseed/altitude/aoa/input sensitivities, etc 

 

Thank you

Posted (edited)
8 minutes ago, xrx said:

hold a sec

C and E is same airplane from aerodynamics point of view, it does have the same frame (exclude minor variations second seat etc)

- length/height, wingspan, wing area, wing airfoil model -- according to wiki specs its exactly apples to apples

- engines are dual pratt whitneys f100pw220s exactly same 65 kN dry thrust (newer pw229 has 80kN)

https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15_Eagle

https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15E_Strike_Eagle

only difference is internal fuel tanks, which built for different tasking  - but clean config is exactly same

 

again - at same clean config and total weight it has to fly C and E exactly same, it terms of acceleration, top speed, alt limit

 - it would be interesting to show community reference curves how f15c f15e different airpseed/altitude/aoa/input sensitivities, etc 

 

Thank you

1000% false.  All of it.

You have over 20 units of additional drag and a different engine that consumes more gas.  

And comparing it to the C that has a very simple engine model is not the way to prove your point here.  Wikipedia isn't either.  Comparison to something quantifiable in real life would be...which is where the numbers came from.

Again, there are no issues there.

 

 

Edited by Rainmaker
  • Like 4
Posted
1 minute ago, xrx said:

could you point out public aerodynamics ref tables that you modeling F15E against, raw tables or analytical curves, would be more valuable to believe so

NASA is full of them.  Search their site.

  • Like 3
Posted
On 10/24/2023 at 4:29 AM, xrx said:

only difference is internal fuel tanks, which built for different tasking  - but clean config is exactly same

But we don't have the same clean config in DCS as F-15C - our modeled F-15E has non-removable CFTs - with huge drag penalty. You can barely touch M2.0 with these on.

You're new here so bear in mind that in order to make devs change something you better provide some hard facts as IRL docs (better in PM to make sure you're not breaking forum rule 1.16 https://forum.dcs.world/guidelines/ ). You don't seem to be knowledgable enough to keep discussing this subject. And, no, they don't provide their docs to prove you wrong.

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Posted (edited)

f15c f15e side by side

both weigh 43k lb (f15e less fuel to match), @alt 55k 1000kn tas both get same airflow, both around 3deg aoa, both run same pratt whitney turbofans.

15k vs 26k is almost twice the difference, wouldnt bother was it close.

to what ff pph means is there anything more to measure correctly?

attaching trk file test air speed ff.miz

Edited by xrx
Posted
3 hours ago, xrx said:

both run same pratt whitney turbofans.

They are far from the same and I like how you omitted drag, just for convenience :thumbup:

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Posted (edited)

i dont understad

both f15c and f15e same pw220 engines (didnt intend to omit anything), build under same roof

what drag you talking about? fuel flow twice the difference whers that coming from?

only thing is which of ED or RAZMAM model more superior, f15c ED model wasnt updated since inception (about 10y ) tells thats pretty good reference..

 

Edited by xrx
Posted
26 minutes ago, xrx said:

i dont understad

both f15c and f15e same pw220 engines (didnt intend to omit anything), build under same roof

what drag you talking about? fuel flow twice the difference whers that coming from?

only thing is which of ED or RAZMAM model more superior, f15c ED model wasnt updated since inception (about 10y ) tells thats pretty good reference..

 

 

The E in DCS has the 229, not 220.

Additionally, the E has CFTs that provide additional drag compared to the C without CFTs-

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Posted
31 minutes ago, xrx said:

f15c ED model wasnt updated since inception (about 10y ) tells thats pretty good reference..

You're wrong - it was corrected and fixed many times and is still waiting for minor fixes. It's differen't aircraft - get it over with - and as said - not modeled to the same degree of fidelity but flight model is still very good.

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Posted (edited)

find it hard to believe side CFTs cause pph fuel rate nearly double at M1.5 compared to F15c (original ED modeling)

it adds frontal cross section very minor relatively to the rest of the frame

since you dont provide any public ref tables/nor your own, it could be any point in the air

Edited by xrx
Posted

It's called drag index. Have a read here:

 

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