Advanced Flight Model for other aircrafts!
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Join Date Sep 2015 and already trying to piss some one off.
Its easy to be a critique with out showing proof, but don’t bother cause we know its not perfect but still a lot better then it was.
Good Day Sir.
I think you are replying to me. So my join date is relevant ? Seriously ?
Atm, F18 is completely OP, period. Flight model is not realistic at all, you can almost turn 180° without moving position, etc.
What, am I trolling ? I am just posting facts, if you think F18 is realistic, it is your problem but 1) my join date have nothing to do with this and 2) I am just asking for a realistic flight model for a plane I think should get some love.
Good day sir.
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I think you are replying to me. So my join date is relevant ? Seriously ?
Atm, F18 is completely OP, period. Flight model is not realistic at all, you can almost turn 180° without moving position, etc.
What, am I trolling ? I am just posting facts, if you think F18 is realistic, it is your problem but 1) my join date have nothing to do with this and 2) I am just asking for a realistic flight model for a plane I think should get some love.
Good day sir.
F18 is indeed FUBAR
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I think you are replying to me. So my join date is relevant ? Seriously ?
Atm, F18 is completely OP, period. Flight model is not realistic at all, you can almost turn 180° without moving position, etc.
What, am I trolling ? I am just posting facts, if you think F18 is realistic, it is your problem but 1) my join date have nothing to do with this and 2) I am just asking for a realistic flight model for a plane I think should get some love.
Good day sir.
Yzangard
Sorry if I jumped down your throat. I do apologize.
Actually I haven’t flown the 18c yet & after waiting so long for an official release I also will be disappointed if it is truly forked. I had heard there was a problem at high altitude, and intend to tinker with it later. But hearing you say it was not worth flying did seem a bit unquilified.
If your talking about the Super Hornet then I didn’t have any expectations there.
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Hi “molnibalage”,
Indeed, in reality there can be two charts for which the thrust slopes as a function of Mach and altitude could not be the same for 2 different engines, even if they’re of the same type or class (ex: turbojet, turbofan with x number of bypasses, etc.) and this has mainly to do with the inlet and inlet duct designs and partially with the flow characteristics through the rest of the engine until it meets the outlet and there’s a clear example here as the TF-404GE’s FULL AB thrust curves (that “l3crusader” has provided on page 5) differ quite much as slopes and peak values from the AL-31’s FULL AB thrust that you’ve linked, so it’s hard to find an overall function that can satisfy all situations in a global manner, which I tried…! There might be software which can simulate (with a given accuracy) some results according to an engine design with a given amount of detail, yet I haven’t used any kind of software to estimate engine performance at all. All I did was to take a crude F-16 Block 50 GE engine’s data, make a picture of how the thrust curves look like as a function of Mach and alt and only tried to adapt these curves for the engines of the aircraft which I’ve worked on to provide better aero data, so I must admit that I didn’t work very hard on the engines data individually and only used a multiplier for all functions, taking care to match the max. thrust given by wikipedia at the same Mach number for which the F-16’s GE thrust value is shown by wikipedia, thus not altering the function’s shape. At least, this was my idea of transferring these functions to all other aircraft knowing that the F-16’s GE has the real measured data and I can trust it. It might’ve been non-recommended doing this, because as seen in this case (and I don’t doubt that in the earlier cases this wouldn’t repeat), the slopes don’t match and are quite far from each-other. Also keep in mind, that in the charts that you linked the thrust is in KN (or at least that’s what it seems), while the charts I’ve updated are in pounds of force. This difference between slopes is indeed a serious problem because it alters the real X axis acceleration of the aircraft and compromises a realistic dogfight experience even if the aero data would be perfectly real, but I didn’t know where to find real experimental data of the engines which I can manually insert (with some passion and patience) and re-check, then save it into the file and fly…! I wasn’t badly intended and I must say again that I’m not specialized in jet engines, all I know is only theoretical and up to a point, I didn’t learn any serious methods to estimate engine thrust yet…, maybe I’ll take the time to enhance this area, but now I’m only concerned to give better aero data mostly.
If the default engine data might be more accurate (I didn’t check), then that should be used instead, meanwhile I can guarantee that the aero data is better, at least up to where the shock stall occurs, and overall good even beyond the shock stall’s Mach number.
If someone can have the patience to provide me any accurate (which is corrected) experimental data (both aero and engine data when possible), I’d start putting that data exactly as it is and stop bothering with mathematical estimations and I think I’ll start doing so for the Lyulka AL-31 for Su-27 and for the F-404 GE of the F-18 as I have them now!
Best wishes!
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Hello,
Sorry I reacted too far as well, I hope there is no bad feeling between us.
Actually, I am talking about both planes, Hornet and Super Hornet. Don’t get me wrong : I love to flight them but their performance isn’t realistic. SuperHornet have some issue with instruments as well but nothing you can’t live with. Issue is this plane won’t be allowed on Falcon Online (for example) because it is too OP.
Right now, F16 (of course) and Mirage 2000 are very good (could even say “perfect” for F16), I realise it is very complicated to get something realistic when you only use F16 flight model as license allows, I was just asking if something could be done to make F18 serie more realistic.
I’m pretty sure they will btw, maybe I’m a bit too impatient.
Regards.
PS : Sorry for kiddish reaction, wasn’t really mature from me.
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Hello,
Sorry I reacted too far as well, I hope there is no bad feeling between us.
Actually, I am talking about both planes, Hornet and Super Hornet. Don’t get me wrong : I love to flight them but their performance isn’t realistic. SuperHornet have some issue with instruments as well but nothing you can’t live with. Issue is this plane won’t be allowed on Falcon Online (for example) because it is too OP.
Right now, F16 (of course) and Mirage 2000 are very good (could even say “perfect” for F16), I realise it is very complicated to get something realistic when you only use F16 flight model as license allows, I was just asking if something could be done to make F18 serie more realistic.
I’m pretty sure they will btw, maybe I’m a bit too impatient.
Regards.
PS : Sorry for kiddish reaction, wasn’t really mature from me.
could you please stop spreading this urban legend
the flight model in bms is able to simulate any aicraft. not only F16.
even a WW2 plane can be simulated with the nfbw module…
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Hi “molnibalage”,
Indeed, in reality there can be two charts for which the thrust slopes as a function of Mach and altitude could not be the same for 2 different engines, even if they’re of the same type or class (ex: turbojet, turbofan with x number of bypasses, etc.) and this has mainly to do with the inlet and inlet duct designs and partially with the flow characteristics through the rest of the engine until it meets the outlet and there’s a clear example here as the TF-404GE’s FULL AB thrust curves (that “l3crusader” has provided on page 5) differ quite much as slopes and peak values from the AL-31’s FULL AB thrust that you’ve linked, so it’s hard to find an overall function that can satisfy all situations in a global manner, which I tried…! There might be software which can simulate (with a given accuracy) some results according to an engine design with a given amount of detail, yet I haven’t used any kind of software to estimate engine performance at all. All I did was to take a crude F-16 Block 50 GE engine’s data, make a picture of how the thrust curves look like as a function of Mach and alt and only tried to adapt these curves for the engines of the aircraft which I’ve worked on to provide better aero data, so I must admit that I didn’t work very hard on the engines data individually and only used a multiplier for all functions, taking care to match the max. thrust given by wikipedia at the same Mach number for which the F-16’s GE thrust value is shown by wikipedia, thus not altering the function’s shape. At least, this was my idea of transferring these functions to all other aircraft knowing that the F-16’s GE has the real measured data and I can trust it. It might’ve been non-recommended doing this, because as seen in this case (and I don’t doubt that in the earlier cases this wouldn’t repeat), the slopes don’t match and are quite far from each-other. Also keep in mind, that in the charts that you linked the thrust is in KN (or at least that’s what it seems), while the charts I’ve updated are in pounds of force. This difference between slopes is indeed a serious problem because it alters the real X axis acceleration of the aircraft and compromises a realistic dogfight experience even if the aero data would be perfectly real, but I didn’t know where to find real experimental data of the engines which I can manually insert (with some passion and patience) and re-check, then save it into the file and fly…! I wasn’t badly intended and I must say again that I’m not specialized in jet engines, all I know is only theoretical and up to a point, I didn’t learn any serious methods to estimate engine thrust yet…, maybe I’ll take the time to enhance this area, but now I’m only concerned to give better aero data mostly.
If the default engine data might be more accurate (I didn’t check), then that should be used instead, meanwhile I can guarantee that the aero data is better, at least up to where the shock stall occurs, and overall good even beyond the shock stall’s Mach number.
If someone can have the patience to provide me any accurate (which is corrected) experimental data (both aero and engine data when possible), I’d start putting that data exactly as it is and stop bothering with mathematical estimations and I think I’ll start doing so for the Lyulka AL-31 for Su-27 and for the F-404 GE of the F-18 as I have them now!
Best wishes!
forget finding engine accurate thrust charts. this does not exist.
dont take f16 engines as reference because of inlets. and engines tuning…
you need to do some retro engineering from em charts and accel charts
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Hi “molnibalage”,
Indeed, in reality there can be two charts for which the thrust slopes as a function of Mach and altitude could not be the same for 2 different engines, even if they’re of the same type or class (ex: turbojet, turbofan with x number of bypasses, etc.) and this has mainly to do with the inlet and inlet duct designs and partially with the flow characteristics through the rest of the engine until it meets the outlet and there’s a clear example here as the TF-404GE’s FULL AB thrust curves (that “l3crusader” has provided on page 5) differ quite much as slopes and peak values from the AL-31’s FULL AB thrust that you’ve linked, so it’s hard to find an overall function that can satisfy all situations in a global manner, which I tried…! There might be software which can simulate (with a given accuracy) some results according to an engine design with a given amount of detail, yet I haven’t used any kind of software to estimate engine performance at all. All I did was to take a crude F-16 Block 50 GE engine’s data, make a picture of how the thrust curves look like as a function of Mach and alt and only tried to adapt these curves for the engines of the aircraft which I’ve worked on to provide better aero data, so I must admit that I didn’t work very hard on the engines data individually and only used a multiplier for all functions, taking care to match the max. thrust given by wikipedia at the same Mach number for which the F-16’s GE thrust value is shown by wikipedia, thus not altering the function’s shape. At least, this was my idea of transferring these functions to all other aircraft knowing that the F-16’s GE has the real measured data and I can trust it. It might’ve been non-recommended doing this, because as seen in this case (and I don’t doubt that in the earlier cases this wouldn’t repeat), the slopes don’t match and are quite far from each-other. Also keep in mind, that in the charts that you linked the thrust is in KN (or at least that’s what it seems), while the charts I’ve updated are in pounds of force. This difference between slopes is indeed a serious problem because it alters the real X axis acceleration of the aircraft and compromises a realistic dogfight experience even if the aero data would be perfectly real, but I didn’t know where to find real experimental data of the engines which I can manually insert (with some passion and patience) and re-check, then save it into the file and fly…! I wasn’t badly intended and I must say again that I’m not specialized in jet engines, all I know is only theoretical and up to a point, I didn’t learn any serious methods to estimate engine thrust yet…, maybe I’ll take the time to enhance this area, but now I’m only concerned to give better aero data mostly.
If the default engine data might be more accurate (I didn’t check), then that should be used instead, meanwhile I can guarantee that the aero data is better, at least up to where the shock stall occurs, and overall good even beyond the shock stall’s Mach number.
If someone can have the patience to provide me any accurate (which is corrected) experimental data (both aero and engine data when possible), I’d start putting that data exactly as it is and stop bothering with mathematical estimations and I think I’ll start doing so for the Lyulka AL-31 for Su-27 and for the F-404 GE of the F-18 as I have them now!
Best wishes!
What I posted as I know is corrected data with intake and other effect. This is why you can see decreasing thrust with increased Mach numb. at low. I simply do not get where came the data what was posted before my post…
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could you please stop spreading this urban legend
the flight model in bms is able to simulate any aicraft. not only F16.
even a WW2 plane can be simulated with the nfbw module…
That was what ppl told me, I don’t know.
Very kind demand. Is there something I should know here or am I just terribly unlucky ?
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That was what ppl told me, I don’t know.
Very kind demand. Is there something I should know here or am I just terribly unlucky ?
Hi Zang , I think its more the avionics that remains hard coded, rather then air frame aerodynamics. At the moment I believe its up there with the best of them, except maybe the atmospheric modeling, though that to is surprisingly disruptive at times.
Not bad for an old girl.
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From my opinion, every other aircraft can be made to fly realistically close to the real one even if using the F-16’s flight model and modifying it accordingly, because after all what could we need to improve their behavior?
1. Realistic moments of inertia values (at least for Ixx, Iyy and Izz), taken either from a form of calculus/calculation or from experimental data;
2. Realistic aero data;
3. Realistic propulsion data.
If these are available, then they can be used into the modified F-16 OFM/AFM flight model data tables and there’s nothing more needed to provide more realism.
As it seems, the F-16’s AFM/OFM flight model is robust enough to carry a wide range of what’s needed for a good simulation and might be able to support even further improvements (this is not up to me though), so it doesn’t seem like every aircraft would need an individual flight model from scratch. The AFM 2 tested on the A-10 (if I’m not wrong), on the other hand, could be another interesting model for flight simulation.Speaking of witch…, I’ll try to get better aero data for the F-18C (Hornet) and E (Super Hornet) also, as I already have engine data chart for the F-404, as discussed earlier (so the C model would promise the most)!
Cheers, good day!
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From my opinion, every other aircraft can be made to fly realistically close to the real one even if using the F-16’s flight model and modifying it accordingly, because after all what could we need to improve their behavior?
1. Realistic moments of inertia values (at least for Ixx, Iyy and Izz), taken either from a form of calculus/calculation or from experimental data;
2. Realistic aero data;
3. Realistic propulsion data.
If these are available, then they can be used into the modified F-16 OFM/AFM flight model data tables and there’s nothing more needed to provide more realism.
Lets compare the F-16 simulated by BMS, with a theoretical F-16 that has the same airframe and engine, but lacks a flight computer and has only a direct mechanical linkage to the flight controls.
One is flyable and the other is not. One has a high performance while the other is very under performing - although it could in theory have the same high performance as the FLCS model, it does not as no pilot can control it quickly enough.
If your flight model is limited to a specific set of flight control laws, you cannot use that to simulate other aircraft automatically. For instance, the Hornet is capable of high alpha maneuvering - the Viper is not, as its control laws prevent sustained high alpha.
This is not an issue for BMS because as mentioned above by the man who coded it, the BMS flight model is not limited to simulating aircraft that share the F-16s control laws.
Your three important things are all essential for getting correct performance - but you also need No. 4 - realistic control laws.
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From my opinion, every other aircraft can be made to fly realistically close to the real one even if using the F-16’s flight model and modifying it accordingly, because after all what could we need to improve their behavior?
1. Realistic moments of inertia values (at least for Ixx, Iyy and Izz), taken either from a form of calculus/calculation or from experimental data;
2. Realistic aero data;
3. Realistic propulsion data.
If these are available, then they can be used into the modified F-16 OFM/AFM flight model data tables and there’s nothing more needed to provide more realism.
As it seems, the F-16’s AFM/OFM flight model is robust enough to carry a wide range of what’s needed for a good simulation and might be able to support even further improvements (this is not up to me though), so it doesn’t seem like every aircraft would need an individual flight model from scratch. The AFM 2 tested on the A-10 (if I’m not wrong), on the other hand, could be another interesting model for flight simulation.Speaking of witch…, I’ll try to get better aero data for the F-18C (Hornet) and E (Super Hornet) also, as I already have engine data chart for the F-404, as discussed earlier (so the C model would promise the most)!
Cheers, good day!
I really wonder how you manage to do all this work, gathering data should be a pain.
Is there a chance to “compute” them with x-plane and its engine to simulate aerodynamism ? (SORRY if this question is stupid, don’t jump down my throat guys).
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Is there a chance to “compute” them with x-plane and its engine to simulate aerodynamism ? (SORRY if this question is stupid, don’t jump down my throat guys).
For the aero data, its possible to use a virtual ‘wind tunnel’ to determine how an aircraft is affected by wind. You want a very good model of the aircraft though, and it will take quite some time (or a fast fast computer). Thrust data, not so much, because its not determined by the shape of the aircraft (well, generally speaking - it is affected by the airflow into the inlet).
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For the aero data, its possible to use a virtual ‘wind tunnel’ to determine how an aircraft is affected by wind. You want a very good model of the aircraft though, and it will take quite some time (or a fast fast computer). Thrust data, not so much, because its not determined by the shape of the aircraft (well, generally speaking - it is affected by the airflow into the inlet).
that would result in very poor modelization
the only right way to do it is retro engineering of em charts and accel charts
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Far be it from me to contradict the expert. You would know more on the topic than I.
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that would result in very poor modelization
the only right way to do it is retro engineering of em charts and accel charts
Those charts aren’t that easy to get I presume…
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Hello again molnibalage,
I’ve already told you how I obtained those thrust curves, in a very rudimentary manner starting from those of the F-16’s Block 50 GE turbofan engine! I should now take Mav’s advice and try using an inverse-engineering technique to get the right curves (and correct values in the most critical parts) by knowing the exact plane’s forward accelerations at a certain drag coef. and plane mass, but only if I can get the correct plane’s acceleration charts at first, or from the plane’s e-m chart using the sustained turn rate, G-load, mass and true airspeed, do the job to estimate the CD (drag. coef) and then immediately find the Drag force = engine thrust for one particular point on the chart.
The e-m charts are much easier to get than acceleration charts (anyway they lead to the same thing), and so I’ll do my best to do what Mav said and painstakingly calculate the necessary thrust in as many points as possible (to obtain a more accurate curve for X altitude) and that’s as accurate as I can estimate thrust tables also from now on.
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Hi Yzangard,
The true pain is with the engine thrust estimation now. Let’s say that I can more or less be on the right track with the aero coefficients of lift and drag, yet I can’t be 100% sure even here that at some point the error margin wouldn’t get higher than 5% (especially at Mach numbers higher than the Mach drag rise and shock stall appearance Mach).
Took me long enough indeed until I was able to obtain more correct data for the MIG-23ML (that I started with), by correcting and re-correcting my mistakes and other errors, but now as I can better trust the aero results, it doesn’t take very long to get on with them.
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Those charts aren’t that easy to get I presume…
…no, they are not. But if you did have them, you could back out the thrust required to model engine behavior to match, and interpolate to fill the gaps. In fact, that is what you would have to do, I think. And outside of that, you’d also have to know something about how the subject aircraft flight control system works in order to model it’s maneuvering behavior properly…particularly for any fly-by-wire sort of aircraft. The F-16 FCLS and it’s control philosophy are a bit unique…and somewhat outdated by today’s engineering. It really doesn’t apply to any jet other than an F-16…unless that jet is also built by the same manufacturer. One can probably assume that for any aircraft.