Is anybody else excited about the new 20 KM CFD in SU11?

[simbol 5,832]

9 minutes ago, jcomm said:

@Simbol,

have you been able to find out why the heck doesn't "CFD-enabled Prop" start rotating in a free-running turbine, with it's engine "dead" and blades in feather,  when the aircraft is put into a sideslip ?

I have run several tests with the Caravan and B200, and was unable to get the proper behaviour with a feathered prop, and it puzzles me since it's a basic aerodynamic consequence of a blade being an airfoil and a sideslip attitude "offering" it the necessary AoA.

I am willing to test it again in SU11...

I've been able to fly a friends Sting and actually thermal in it for a good while 🙂

The guy, who had never flown a glider, was astonished at "how efficient the climb was" as we entered the thermal 🙂

Of course it's ot a Sinus, but it does a nice work !

Now you turned my interest into your S4 😉

 

Well, yes this drives me crazy too. The logic behind prop feathering is not really working IMO. Not many of you might now, but I am now building turbo props (Piper M500 and Piper M600) and I found several bugs with "Modern Prop Physics", things like the thrust, beta range, engine behaviours, ITT, etc. as a result I am building these turbo props using CFD but "old prop physics" and complementing things via my own custom Physics simulation until Asobo addresses the problems. Remember with Sting S4 I created a full ballistic parachute, and this uses custom flight physicis to simulate the airplane stopping and dropping from the sky, so I have plenty of experience regarding how to complement things when required, something my Turbos will have.This week I did for example a full custom ITT temp simulation and Fuel Flow consumption to achieve proper engine starts and behaviours in accordance to Piper M500 POH. The reason? I was unable to achieve these results using the default MSFS configuration files and SDK functions, so I had to extend these with my own solution (Yes, the SDK allows devs to extend simulation, you just need the skills).

It is important to clarify that we must not mix modern prop physics with CFD, again these are technologies that complement each other, you can have old prop physics + CFD.. or new Prop physics and no CFD.. and when you have both, you can link them together and make them work together (the ultimate goal).

Having said that, in all cases, the assumption of the core MSFS simulation is that when a prop is feathered it should stop, it doesn't take in consideration side forces, it is assuming that because it is feathered it should not rotate, I never thought about what happens when you go into a slip and I thank you for tagging me on this post because now I can code this custom behaviour to my 2 upcoming products (evil laugh muahahaha).

Turbo Props needs lots of work from MSFS, the good news is there are very good devs out there like (Alex SWS) and myself reporting these issues to Asobo and providing our feedback, personally I am codding custom solutions when I find a limitation on the default configurations for Turbos so end users can experience things as real as possible. Alex likes to use different techniques to achieve the goals, he is incredible smart, so although he is not using CFD at the moment, you can still perceive the airplane simulation very close to IRL.

Best,

Raul

[mrueedi 702]

 

4 hours ago, blingthinger said:

In fact, "force element" doesn't show up anywhere in the 8000 words. Not once. I realize the videos use that term, but why then is the SDK different?

I do also see reference to FSX many many times: Use of the the FSX tables. Normalizing to match the FSX tables. Etc.

Help, mrueedi. SDK says one thing. You say another. So confused here.

No, the SDK says not "one thing". It simply says nothing about many things. It has gaps. It does not expressly and specifically say everything that could be said. Especially not the obvious. It is not written for dummies. You will not have the full picture, if you just read the essay about flight physics.

So your questions come from your unwillingess (or is it inability?) to fill the gaps with information from other sources (like the videos) and apply some logical thinking. Connecting the pieces of information requires an intelectual effort on your side. But you refuse to understand in order to spread misinformed and dead wrong conclusions. I have posted half a book in the last thread explaining you the obvious, which you could have read just by yourself.

And btw, the document which you call the SDK all the time is not "the SDK". It is just an essay about fundamental concepts which actually for the largest part are not needed by flight model developers. To develop addons, this part of the SDK is needed:

Defining A Flight Model (flightsimulator.com)

And here you also find e.g. the evidence that the forces are calculated per surface.

So, please, if you have not understood the surface model after all the explanations you received it is a good moment to leave it at that, and just accept that. Or accept, that the essay has gaps. Trying to explain the meaning of the words in the essay to you, is like trying to explain quantum mechanics to a first grader.

4 hours ago, blingthinger said:

100% agree. If someone in that corporate mix hadn't demanded backwards compatibility with FSX products (does it ever get used??), the model could have been so much better. Based on the SDK, FSX remains at the core of the force element model.

So sad.

Wrong. The new model is so "much better", because the legacy and the new model run side by side. Stop spreading wrong information. You clearly do not understand enough to draw conclusions about the role of FSX in the new MSFS flight physics.

 

[jcomm 6,061]

1 hour ago, simbol said:

Turbo Props needs lots of work from MSFS, the good news is there are very good devs out there like (Alex SWS) and myself reporting these issues to Asobo and providing our feedback, personally I am codding custom solutions when I find a limitation on the default configurations for Turbos so end users can experience things as real as possible. Alex likes to use different techniques to achieve the goals, he is incredible smart, so although he is not using CFD at the moment, you can still perceive the airplane simulation very close to IRL.

Best,

Raul

Thank you @simbol for replying!

Yes, but I guess it's in the right track, and they ASOBO are doing  a great job with the active updates from SU to SU.

I am really looking fwd to get my hands on SU11 + 40 th !!!

One question - is your S4 the one available only through the marketplace ?  No problem with that - I have other marketplace-only aircraft - but I just don't want to search for the wrong product!

Really looking fwd to try it !

Edited November 10, 2022 by jcomm

[NZ255 312]

34 minutes ago, jcomm said:

One question - is your S4 the one available only through the marketplace ?

Yes, informative write up about it here: 

 

[simbol 5,832]

12 minutes ago, jcomm said:

Thank you @simbol for replying!

Yes, but I guess it's in the right track, and they ASOBO are doing  a great job with the active updates from SU to SU.

I am really looking fwd to get my hands on SU11 + 40 th !!!

One question - is your S4 the one available only through the marketplace ?  No problem with that - I have other marketplace-only aircraft - but I just don't want to search for the wrong product!

Really looking fwd to try it !

Hi there, yes it is available only via Market Place. Just search for Sting S4 and you will find it.. or FSReborn :)

 

R.

[jcomm 6,061]

34 minutes ago, simbol said:

Hi there, yes it is available only via Market Place. Just search for Sting S4 and you will find it.. or FSReborn 🙂

 

R.

Purchased!  Looking fwd for the first test flight 🙂

[Bartul 47]

Is anybody executed you say?  I don't know, but i hope not, cause i have a first row free pass when it comes to executions.

[lwt1971 7,517]

4 hours ago, simbol said:

It is important to clarify that we must not mix modern prop physics with CFD, again these are technologies that complement each other, you can have old prop physics + CFD.. or new Prop physics and no CFD.. and when you have both, you can link them together and make them work together (the ultimate goal).

Turbo Props needs lots of work from MSFS, the good news is there are very good devs out there like (Alex SWS) and myself reporting these issues to Asobo and providing our feedback, personally I am codding custom solutions when I find a limitation on the default configurations for Turbos so end users can experience things as real as possible. Alex likes to use different techniques to achieve the goals, he is incredible smart, so although he is not using CFD at the moment, you can still perceive the airplane simulation very close to IRL.

Excellent insights @simbol thanks again, and yes agreed turbo props is an area that needs more work in the core platform but great that devs like you are funneling feedback back to Asobo.

Another question: Asobo haven't put out the how-it-works details behind SU11's atmospheric CFD airflow modeling yet, but I was wondering if it's entirely independent from aircraft CFD from what you've been able to look into? i.e. do aircraft FMs need to be enabled with CFD (that's been there since SU9) to fully take advantage of and interact with the coming atmospheric airflow in the 20km cocoon around the aircraft? So an aircraft like the Sting S4 which has the modern flight model + CFD, versus another that just has the modern flight model, will they behave the same within the new SU11 atmospheric airflow model? On one hand sounds to me like the aircraft needs to be CFD enabled in its FM for the new airflow to fully interact with the bird in flight.. But then again I'd think the new turbulence/draft modeling should impact both types of aircraft FMs the same.
 

Edited November 10, 2022 by lwt1971

[Cpt_Piett 4,898]

2 hours ago, jcomm said:

Really looking fwd to try it !

I have to admit that I went ahead and bought it (the Sting S4) yesterday after reading this thread 🙂 After sitting on the fence for a while. First flight I did some "soaring" over the hills near Santa Barbara, then an engine-out glide towards the coast from 5000ft or so. It's a fun aircraft! Now I have to practice the wing-low crosswind technique. 

There's the issue with the (IMO) excessive movement in the yaw axis even in light winds, which is not specific to this aircraft. I would love to hear the developer's thoughts on this, as this is something we're discussing in another thread. 

In terms of turboprop simulation, there's been a lot of discussion on this in the official forums re: the Black Square King Air. AFAIK they've done a great job with the help of JayDee, but are not quite "there" yet. 

Edited November 10, 2022 by Cpt_Piett

[jcomm 6,061]

1 hour ago, Cpt_Piett said:

I have to admit that I went ahead and bought it (the Sting S4) yesterday after reading this thread 🙂 

 

Makes 2 of us 🙂  I was even faster ...

I found a few minutees to give this new MFS addon a try, and I really enjoyed the first flight.

I tried to remember the rw experience from a flight in an S4 from Benavente airfield (PT-0021). 

We have to filter the overdone response of all light ( and not only ) aircraft to the wind variation in MFS, but that's not a fault in the aircraft model itself but rather on the MFS simulation platform, and ASOBO are aware of it and I'm sure will continue to improve the way this effects impact on aircraft behaviour inflight.

The S4 was nimble, very responsive ( for sure a lot more than the gliders I am used to fly ).

I could easily identify what I recall of the main flight characteristics in this model! Good work!  OFC I didn't takeoff or land the real S4, so, I can't really tell how close it feels during those phases of flight, but my experience in the right seat makes the way the S4 behaved in MFS rather plausible.

The higher than usual glide ratio makes it interesting for good soaring days, but for that I am specifically looking forward for the new gliders in SU11 + 40th 😉

Found only one weird effect with the prop suddenly stopping and then starting to turn again ( windmilling ) when I tried killing the engine and performed some maneuvers. I climbed to 6000', cut the engine, and then tested windmill. As I climbed and the relative wind dropped, the prop suddenly stopped. Then as I lowered the "nose" to gain speed and recover, the prop all of a sudden started rotating fast, on both transitions there being apparently no visible proggressive variation. I guess this is probably due to the custom code being used to cope with other limitations of the prop model in MFS (?). But this is just a tiny detail!

Congrats @simbol for the excellent work in this really nice ULM !

Edited November 10, 2022 by jcomm

[SAS443 1,749]

11 minutes ago, jcomm said:

I climbed to 6000', cut the engine, and then tested windmill. As I climbed and the relative wind dropped, the prop suddenly stopped.

Typical Rotax behaviour due to high compression. The prop is very stiff to rotate in preflight as well when performing the oil check/gurgle. 

It wont windmill when flying best glide, at least not the Rotax 912 100hp engine I am familiar with.

[jcomm 6,061]

2 minutes ago, SAS443 said:

Typical Rotax behaviour due to high compression. The prop is very stiff to rotate in preflight as well when performing the oil check/gurgle. 

It wont windmill when flying best glide, at least not the Rotax 912 100hp engine I am familiar with.

It's probably more like a graphic glitch. The stop is ... like... instant, just as the startup when speed builds up again, but it's ineteresting to know about that particular feature of the Rotax engines. Thx!

[simbol 5,832]

1 hour ago, jcomm said:

Found only one weird effect with the prop suddenly stopping and then starting to turn again ( windmilling ) when I tried killing the engine and performed some maneuvers. I climbed to 6000', cut the engine, and then tested windmill. As I climbed and the relative wind dropped, the prop suddenly stopped. Then as I lowered the "nose" to gain speed and recover, the prop all of a sudden started rotating fast, on both transitions there being apparently no visible proggressive variation. I guess this is probably due to the custom code being used to cope with other limitations of the prop model in MFS (?). But this is just a tiny detail!

Rotax have a very high gear ratio and they are supposed to practically stop as soon as the engine is turned off, however MSFS doesn't support this concept unless you feather the prop, which is not what happens on Rotax engines.. so I had to code my own wind mill simulation to cater for this scenario.. I also coded proper choke lever behaviour (not supported by MSFS by default) and also inverted fight carburated engine behaviours too.. give it a go.. 

The wind milling speed was tweaked with a help of a real world Sting S4 pilot who was brave enough to perform these tests on his own aircraft, one of the liveries in the package is dedicated to him given all his efforts to help me bring the product as close as possible to IRL. But let's not forget something, I am not promising study level airplanes, neither the cost of my products is reflecting this..  they are not priced as study level.. what I am offering is a new immersive experience and a different type of products coming to the market with unique features, for example, blow out one of your rear wheel tyres when you land.. brace yourself for the experience..

Best,
Raul

Edited November 10, 2022 by simbol

[simbol 5,832]

35 minutes ago, SAS443 said:

Typical Rotax behaviour due to high compression. The prop is very stiff to rotate in preflight as well when performing the oil check/gurgle. 

It wont windmill when flying best glide, at least not the Rotax 912 100hp engine I am familiar with.

Correct and it is what I tried to reproduce :)

[jcomm 6,061]

3 minutes ago, simbol said:

But let's not forget something, I am not promising study level airplanes, neither the cost of my products is reflecting this..  they are not priced as study level.. what I am offering is a new immersive experience and a different type of products coming to the market with unique features, for example, blow out one of your rear wheel tyres when you land.. brace yourself for the experience..

Best,
Raul

Raul,

and for me it's already good enough as it is... My observation was a picky one, not really impacting what is more important - the plausibility of the flight characteristics and details being simulated!