Free Falcon 5.5

[mav-jp]

 

What I'm saying, is that if you had an completely unknown function of 8 variables,

there would be no guarantee you could split it, and you would worst case end up with

an 8 dimensional table that likely would be too large.

 

Again in this case, your function isn't completely unknown (the opposite case of what

I've been talking about all along), so it isn't an 8D table.

 

this is what i call math masturbation and has absolutly no interest for engineering purpose ;) ;)

[RvEYoda]

Well what people tend to forget is that EVERYTHING IS A MODEL, even the Navier Stokes Equations are a model ; the Turbulence equations are a model....so saying you can find the analytic solution of the problem is pure Math mind masturbation.

 

Nobody has stated anything else, but if someone claims he can table solve/store an 8D completely

unknown equation with good precision, I will not sleep until he shows me what ram he has got :P.

Edited May 19, 2010 by =RvE=Yoda

[mav-jp]

Nobody has stated anything else, but if someone claims he can table solve an 8D completely

unknown equation with good precision, I will not sleep until he shows me what ram he has got :P.

 

In that case the 8D assumption is already incorrect, because it comes from a simplified model. you then need a more complex model rather than an interpolated model.

 

but i'm saying complex model is NS and is not usable for real time computation.

 

8D has no interest because you use dat or order of importance too low.

 

so there is no "in between" like 8D table

 

there is

 

1) NS

2) Physical interpolation which needs ~ 2 Mb to get accurate modeling, adding data would be useless

 

i dont believe in the

 

3) simplified NS , which is what X plane does... :)

[mav-jp]

Anyway , to get back on the original subject.

 

FF5.5 has the same falcon4 FM ? ;)

[RvEYoda]

In that case the 8D assumption is already incorrect, because it comes from a simplified model. you then need a more complex model rather than an interpolated model.

 

For the case of solving your model as stated, yes, for the general case no.

Again, like I wrote I have not studied your model, so i can only draw conclusions

about the general case. If I come across a completely unknown system of 8 paramers

I'd have to do it my way, which assumes no model at all.

 

 

but i'm saying complex model is NS and is not usable for real time computation.

 

8D has no interest because you use dat or order of importance too low.

 

so there is no "in between" like 8D table

 

there is

 

1) NS

2) Physical interpolation which needs ~ 2 Mb to get accurate modeling, adding data would be useless

 

i dont believe in the

 

3) simplified NS , which is what X plane does... :)

 

I have no disagreements with what you say here.

[mav-jp]

For the case of solving your model as stated, yes, for the general case no.

Again, like I wrote I have not studied your model, so i can only draw conclusions

about the general case. If I come across a completely unknown system of 8 paramers

I'd have to do it my way, which assumes no model at all.

 

 

 

 

I have no disagreements with what you say here.

 

the fact that you would chose 8 parameter is already a model ;)...

 

 

you can not say 'i have no model', even NS is a model ...

 

and by the way, I dont have "My" model, NASA had a model ;)

[RvEYoda]

the fact that you would chose 8 parameter is already a model ;)...

 

you can not say 'i have no model', even NS is a model ...

 

Perhaps you could call it that but I assume no shape at all about hwo the function looks.

The question is not "if", the question is "how much".

 

Of course NS is a model (still I have never seen it)

 

F=ma is a model, world model hehe :P.

Edited May 19, 2010 by =RvE=Yoda

[mav-jp]

Perhaps you could call it that but I assume no shape at all about hwo the function looks.

The question is not "if", the question is "how much".

 

Of course NS is a model (still I have never seen it)

 

what you are saying ha no meaning to me:

 

*Whether you have an interpolated linear model and you know perfectly what are the number of parameters you want to use and the order of importance of it, in that case, i think the NASA model is quite correct and as explained you dont need 8D data...

 

* whether you have a non linear model and the last known is Navier stokes...

 

I dont deny you could propose a linear 8D model but it can NOT be unknown , you need to know it to measure it - or compute it with non linear model.

[mav-jp]

Perhaps you could call it that but I assume no shape at all about hwo the function looks.

The question is not "if", the question is "how much".

 

Of course NS is a model (still I have never seen it)

 

F=ma is a model, world model hehe :P.

 

you have never seen NS modeling ?

 

 

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you need to add some turbulence equations modeling, (like kolmogorov) plus boundary limits equations

 

blah blah blah ...

 

what about FF5.5 ???

[RvEYoda]

what you are saying ha no meaning to me:

 

*Whether you have an interpolated linear model and you know perfectly what are the number of parameters you want to use and the order of importance of it, in that case, i think the NASA model is quite correct and as explained you dont need 8D data...

 

* whether you have a non linear model and the last known is Navier stokes...

 

I dont deny you could propose a linear 8D model but it can NOT be unknown , you need to know it to measure it - or compute it with non linear model.

 

Example: You have been told you need to investigate the shape of a function depending on 2 varaibles:

F = F(A,B). You are also given a range of A and a range of B

 

You are also given access to an abstract tool, which given a value of A and a value of B gives

you a value of F. Now you want to make a heightmap plot or something simple to describe the

function. You have no more knowledge about the system except you have been told it has two

inputs. The case is not meaningless.

 

 

Variables A,B,C,D,E,F,G,H *enters* [bLACK BOX] *produces* pair of shoes.

For example [bLACK BOX] = wind tunnel :)

 

 

Like you have shown the case of NS is NOT = [bLACK BOX], but again, NS is just a case.

 

I agree with you, properly stated tables will probably yield far better results if the mdoel

is complex and the needed simplifications to solve it in real time will significantly reduce

the solution accuracy.

 

------------

 

Afaik falcon 5.5 fm are just data edits, but I could be wrong :P

Edited May 19, 2010 by =RvE=Yoda

[mav-jp]

Example: You have been told you need to investigate the shape of a function depending on 2 varaibles:

F = F(A,B). You are also given a range of A and a range of B

 

You are also given access to an abstract tool, which given a value of A and a value of B gives

you a value of F. Now you want to make a heightmap plot or something simple to describe the

function. You have no more knowledge about the system except you have been told it has to

inputs. The case is not meaningless.

 

correct , and after 40 years of testing, some people have concluded that for aerodynamic effects, most of the dependances are of the second, third of more orders which allows us to simplify / reduce the problem.

 

Why the hell do you want to re do the work already done ?

[RvEYoda]

correct , and after 40 years of testing, some people have concluded that for aerodynamic effects, most of the dependances are of the second, third of more orders which allows us to simplify / reduce the problem.

 

Why the hell do you want to re do the work already done ?

 

Never said I wanted to, but if someone says "this is true" to me I say

"hang on" until I'm showed why.

 

I aint going to be satisfied until I know hwo to implement it :)

(which you basically showed here)

Edited May 19, 2010 by =RvE=Yoda

[mav-jp]

Never said I wanted to, but if someone says "this is true" to me I say

"hang on" until I'm showed why.

 

I aint going to be satisfied until I know hwo to implement it :)

(which you basically showed here)

 

reading the NASA implentation is a good start :)

[RvEYoda]

reading the NASA implentation is a good start :)

 

OK. I will do that. Btw do you know of any proposed FEM solutions to the problem?

I always thought it would be an idea to reduce the complexity of whatever equations used

and instead use more separate lift/effect zones on the aircraft.

Edited May 19, 2010 by =RvE=Yoda

[mav-jp]

OK. I will do that. Btw do you know of any proposed FEM solutions to the problem?

I always thought it would be an idea to reduce the complexity of whatever equations used

and instead use more separate lift/effect zones on the aircraft.

 

ho yeah i have already investigated that possibility, i.e creating a CL/CD curve for each surface and compute locally the speed, alpha, beta to get the force from each surface and then integrating the whole thing

 

It works..., but :

 

1) is extremly difficult to create the data (you need to know the CL/CD of elevator, rudder , etc etc.. which is difficult to have).

 

2) you dont simulate interaction of the surfaces with the others, so you need aditionnal modeling for interaction.

 

all in all..it works but it's difficult to get it work right ...whereas globalmodeling can be much more accurate (all effects are in already)

[RvEYoda]

ho yeah i have already investigated that possibility, i.e creating a CL/CD curve for each surface and compute locally the speed, alpha, beta to get the force from each surface and then integrating the whole thing

 

It works..., but :

 

1) is extremly difficult to create the data (you need to know the CL/CD of elevator, rudder , etc etc.. which is difficult to have).

 

2) you dont simulate interaction of the surfaces with the others, so you need aditionnal modeling for interaction.

 

all in all..it works but it's difficult to get it work right ...whereas globalmodeling can be much more accurate (all effects are in already)

 

1,2 agreed.

 

What about something like this (terribly unpractical and doesn't take all effects into account,

but might be possible to do ;)): You put the F-16 on mount #1. Then you cut off an elevator

from the main aircraft model but keep it in the same place, just on a separate mount #2.

Now you run your tests but measure only the forces/moments on mount #2

 

Perhaps defeats its own purpose, but I think it would be fun to see :)

Edited May 19, 2010 by =RvE=Yoda

[sobek]

Sounds exaclty like the Fighterops.

 

Maybe that's why it's taking them so long, creating a table from NS by hand :D

[GGTharos]

Yep, just write it all out ;)

Sounds like they're doing pretty much what X-Plane/DCS etc are doing.

 

Maybe that's why it's taking them so long, creating a table from NS by hand :D

[rattler]

Well maybe through all of this they are on to something.:book:

[GGTharos]

Different applications of the same thing.

X-Plane might be generalized or use an aerodynamics modeling method different from what they want to use.

 

I think the biggest concern for them though would be supersonic modeling, since modern jet fighters tend to be that - sueprsonic ... while X-Plane's FM is mostly accurate for subsonic simulation only, IIRC. Of course, that could just be one single factor.

 

The point here is that breaking up the surface to many 'strips' or areas, shall we say, and calculating forces on each is not a new idea. Su-25 in FC already does it.

 

The Ka-50 has each rotor blade broken up into 5 sections, and so on and so forth.

 

The A-10C FM will be advanced beyond the Ka-50's as well, but what that actually means is a mystery to me :)

 

As far as i know, they were appealed to look at X-planes construct way back in early days and came to the conclusion to construct their completely own unique

and new solution, cuz x-plane was not sufficient enough in that matter.

[rattler]

Guys:

 

Your talks have been interesting but now if you could move closer together on each others thoughts on the subject, maybe the two of you could come up with a viable solution that can be used to more effectively produce better simulation FM. This is how a problem really gets solved. Now see if you can both come closer together and see if at least maybe you can stumble across a better solution to the problem. Now time to look at each others thoughts and just maybe something might pop out, that has been overlooked. Seriously. Its chats like this that sometimes bares fruit.:book:

[GGTharos]

No. There are far more qualified people to do this.

 

maybe the two of you could come up with a viable solution that can be used to more effectively produce better simulation FM.

[mav-jp]

so OF does (with slightly variations, described in link, btw we had once a discussion you and me way back in days in frugals pm mav-jp, i remember asking you)

 

http://forums.eagle.ru/showthread.php?t=49792

 

and for practical purpose this might be usefull:

 

www.as-private.com/FlightDocs/F-16C-52-Performance-Charts.rar 77 Pages pdf

 

i know that all Falcon4 versions use HFFM , that is for sure...

 

the question is did FF5 change the Falcon FM core ?

 

answer is no

 

therefore Falcon4 FM remains shit :)

[rattler]

Hell guys:

 

Its not always the so called brains that solve problems. Lots of solutions have come from people such as yourselves. Chit chat back and forth on a topic like this could very well have results. Don't sell yourselves short. This is how progress is made and not always by who you think. All it takes is something to pop up that was overlooked, now the brain people can take and run with it. Group discussions is always a good way to solve a problem. Does not mean everyone has to a brain child. Most times they get tunnel vision and it takes something like this to get a better perspective on the subject. Cheers guys.:thumbup:

[Dave_s]

There should be a big banner warning on the download sites advising about the issue with Nvidia cards.

 

Just wasted a gig of bandwidth :doh: