41 minutes ago, abrams_tank said:

Why do you XP users have to come here and cause all these problems? Maybe you can stay in your XP forum instead?

You are doing just as much to keep alive the 'them and us' squabbling as those you complain about.

Enough, please.

 

Guys. Let’s just chill out. Read the subject prior to posting.  

45 minutes ago, blingthinger said:

I hear you, Ray. I tried many times to avoid the XP discussion. Granted, I'm not going to just let blatant misinformation just slide...so I have directly addressed shots fired, but my most recent post was a direct question for about Asobo's FM CFD. So, maybe not weather-related, but still CFD-focused. Still waiting for lwt to answer, given it was referring to one of their own comments.

Ok let's try it this way... you were hung up on:
1) my use of the word "driven" which didn't suit the way you'd use it in "scientific/engineering" ways, whatever that means, but sure
2) the fact that various MSFS users on this thread were lauding MSFS's new atmospheric airflow as "advanced" or "ground breaking" which you then conflated and made up info (i.e. misinfo) that it's actually MS/Asobo themselves who were saying this... and when corrected you then said well it's "misinformation" from MSFS fans. If MSFS fans describe whatever feature(s) of this sim as "advanced" or whatever, that does not equate to misinformation as they are just opining... and being insecure about it is not a good look.

Apart from above, we actually agree on the fact that the local-aircraft-CFD (i.e. "FM CFD" as you term it) can only truly shine if MSFS's SDK allows much more varied and detailed definition of aircraft geometry and definition. But that said, 3rd party devs like FSReborn and others have also employed local-aicraft-CFD in great-flying birds like the Sting S4, so I'm definitely curious as to what their thoughts on this are (but it's up to them to respond if/when they care to). But even with that inability to define aircraft geometry in a fine-grained way, the core engine has obviously been more than capable with the entire set of features it provides to result in great flight models such as the Fenix A320, Milviz C310, PMDG 737, etc who don't use local-aircraft-CFD. The coming core support for helicopters also is using CFD to simulate various aspects of helicopter physics it looks like per what Asobo recently shown, so another way to evaluate local-aircraft-CFD once the 40th anniversary edition releases (apart from the default C172)

As to your specific question about if Asobo mentioning anything about changes coming for this, not that I know of.

And which exact part of the SDK do you think is a "lie"? (can you link to the exact docs page?). And why/how?
https://docs.flightsimulator.com/html/Samples_And_Tutorials/Primers/Flight_Model_Physics.htm
https://docs.flightsimulator.com/html/Samples_And_Tutorials/Tutorials/Defining_A_Flight_Model.htm

And finally, do you actually use MSFS in its latest incarnations currently? Have you ever used and evaluated it before?
 

Edited November 8, 20223 yr by lwt1971

21 minutes ago, abrams_tank said:

The very first post in Murmur's thread that you brought up was misinformation. Why do you support that?

And if you correct misinformation, that's fine. But do it in a civil and respectful way.

In the same respectful way Murmur was corrected? 

Wonder why is it always so peaceful at the Aerofly FS forums ?

😉

7 minutes ago, BobFS88 said:

In the same respectful way Murmur was corrected?

I was the one who corrected him and all I did was post a youtube link.

8 minutes ago, lwt1971 said:

As to your specific question about if Asobo mentioning anything about changes coming for this, not that I know of.

You're back! You claimed your patience was empty a few hrs ago... But regardless, WHEW! That's all you had to say there. 

As for the SDK, the image of the geometry being modeled by the force elements is a swept wing. The text/math very explicitly says they average all wing geometries down to the "planform model" geometry:

Read the first page, then skipped to the end (apparently avoiding the usual suspects doing the usual things), to just say that it sounds like this will do wonderful things for all you serious flyers out there, but if it's going to make me wobble about all over the place, I hope it will be something I can turn off, like the gusts. I'm primarily interested in an aircraft and a flight as a viewing platform for the world below, and a nice, unrealistic, steady platform is what I like for that.

Reality should be kept where it belongs - in the real world <grin>

11 minutes ago, Krakin said:

I was the one who corrected him and all I did was post a youtube link.

I wasn't talking about you or your post.  Read the thread and figure out why it was locked.

23 minutes ago, blingthinger said:

You're back! You claimed your patience was empty a few hrs ago... But regardless, WHEW! That's all you had to say there. 

As for the SDK, the image of the geometry being modeled by the force elements is a swept wing. The text/math very explicitly says they average all wing geometries down to the "planform model" geometry:

You really need to improve your reading skills 🙂 ... I said I had no more patience to remain talking last night, as I clearly preferred sleep ¯\_(ツ)_/¯

Once again, where exactly is the "lie" in the SDK docs? Yes they make it clear the sim wing model is the planform model derived from a trapezoidal wing hypothesis. This is what they exactly say below, please point out the words that amount to a "lie":

Aircraft description - Wing Geometry

The projection of the wing of the plane on the \(x-z\) plane is called the wing planform. A typical planform is sketched below:

<diagram above>

• \(S\) is the wing area, the area of the planform, where:
  $$S = \int_{0}^{\frac{b}{2}}{c(x)\mathrm{d}x}$$
• \(b\) is the wing span, the maximum lateral extent of the planform
• \(c_{tip}\) is the chord at the tip
• \(c_{root}\) is the chord at the root
• \(\lambda =\frac{c_{tip}}{c_{root}}\) is the tapper ratio
• \(AR=\frac{b^2}{S}\) is the aspect ratio of the planform
• \(\Lambda_n\) is the sweep angle of any constant-chord fraction i.e: the angle formed by \(\boldsymbol{e}_x\) and the line linking all the points located at distance \((1/n)\,c(x)\) from the leading edge. For instance, \(\Lambda_0\) corresponds to the angle between the leading edge and lateral direction \(\boldsymbol{e}_x\).
• \(\Gamma\) is the dihedral angle of the wing
   

And still waiting on the answer for my last question... do/have you actually use/used MSFS? And if so are they the latest versions or an older SU release?

Edited November 8, 20223 yr by lwt1971

18 minutes ago, andy1252 said:

,to just say that it sounds like this will do wonderful things for all you serious flyers out there, but if it's going to make me wobble about all over the place, I hope it will be something I can turn off, like the gusts. I'm primarily interested in an aircraft and a flight as a viewing platform for the world below, and a nice, unrealistic, steady platform is what I like for that.

 

You can already do this just turn off live weather.

16 minutes ago, blingthinger said:

You're back! You claimed your patience was empty a few hrs ago... But regardless, WHEW! That's all you had to say there. 

As for the SDK, the image of the geometry being modeled by the force elements is a swept wing. The text/math very explicitly says they average all wing geometries down to the "planform model" geometry:

Do you think that as long as the Mean aerodynamic chord is in the same  position then a straight wing model can be used with little difference in result for a subsonic model (perhaps replace the lateral stability afforded by wing sweep with slight dihedral) ?

I doubt Asobo models spanwise flow anyway

2 minutes ago, lwt1971 said:

I said I had no more patience to remain talking last night

Ahh, my bad. I will admit to tuning out a few words when you so graciously declared you were "educating me" (by repeating the same errors over and over again)! But your magnanimous benevolence shan't distract us from the real issue at hand:

 

4 minutes ago, lwt1971 said:

Once again, where exactly is the "lie" in the SDK docs?

Which one is it? Swept wing as in the force element pic? Or straight wing as in the text/equations? Which one is the lie? Given that the writeup came from a well-oiled corporate machine such as M$/Asobo, I hesitate to cast it aside as a typo. Especially after all these years. It's a simple fix, no? Why keep a blatant and egregious aerodynamic error in an important document like that?

14 minutes ago, jbdbow1970 said:

You can already do this just turn off live weather.

Ah, thanks for that. I never use live weather anyway so if that's where all this takes place that works out perfectly for all concerned!

3 minutes ago, Sceadu said:

replace the lateral stability afforded by wing sweep with slight dihedral

Increasing dihedral unrealistically? It would be more than just a couple degrees. But that doesn't matter because this statement is also in the SDK:

 

Note that the following geometrical parameters can be prescribed but are used only for debug or gauges indications:

Wing dihedral

Wing position vertical apex

Wing position longitudinal apex

Wing position reference chord

Wing CG reference chord

Wing sweep

Wing twist

 

 

Lack of spanwise flow isn't the biggest problem. Transonics can be tamed a bit in the lookup tables (which they do offer to a limited (some say "crippled" from FSX days) degree). Roll-yaw coupling is the most prominent issue. And it's well known that's a shortcoming of the model. Though I'm thinking that's more a problem of the underlying FSX table lookups (or lack thereof in this case).

Aside though, those are force-element model considerations. In the context of CFD, every geometry variation matters. I guess in this case, unless the model is a Bell X1. There's very clear reasons why the CFD is only used for prop wash and even then has BIG fudge factors like being able to turn entire cells off and on. They might be starting with the continuity and Navier-Stokes equations, but that sure ain't CFD.

'Tis marketing.