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Waldo Pepper

Vertical Wind Analysis - SU11 by ANRI of SimSoaringClub

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ANRI over in the Sim Soaring Club Discord group recently posted a detailed analysis of vertical winds in SU11.    A sizeable number of Avsim users refuse to use discord as a source of information,   so I'm going to relay his post to you all.

Here is an invite link to the SSC discord group,  https://discord.gg/3yZzrGp4

Here is a link to ANRI's post, https://discord.com/channels/876123356385149009/1046456516066168902

Here is ANRI's presentation,  presented in quotations.

Quote
Clouds and cloud thermals
Clouds in MSFS are displayed according to the initially created cloud map and its settings Coverage, Scattering, Density and the programmed cycle of development/extinction. This cloud map is the same for all users, covers the entire MSFS world and moves above the ground according to wind settings. This cloud map has been created and exists in MSFS since the alpha version of this simulator and remains unchanged. This version of the implementation of clouds in MSFS is very simple, but it is better than in other simulators. I don't think the developers will give up on it soon and come up with some more complicated option. A task for developers has been asking for a long time, this is the synchronization of the movement of the cloud map in multiplayer for all the players of the group with a weather preset common to them. Now, the movement of the cloud map in the wind begins for each player from the moment the flight is launched. However, the cloud map has its current coordinates and for synchronization it is enough to transmit these coordinates from the creator of the group to all the players of the group, similar to the rest of the weather preset settings. Comparing the speed of the vertical air flow depending on the density of clouds, on the thickness (height) of the cloud layer, air temperature and wind speed, we can confidently say that these dependencies were better and more correct in SU10 (see Figure 1.) It is possible that simplified modeling of cloud thermals works in SU11, but this is wrong and we are waiting for corrections. (edited)
 
Figure_1.png
Quote

 

The magnitude of the vertical air flow velocity in cloud thermals varies depending on the altitude of the flight (see Figure 2.). I think this dependence is quite correct at altitudes from the ground to a height of 1000 feet, but this speed should not decrease at altitudes up to the lowest base of the clouds, on the contrary, it should only increase. Further, from the base of the clouds to the top of the cloud, this speed should decrease to zero. There should be no cloud thermals above the top of the clouds! In addition, if clouds have their own life cycle, then the cloud thermal should also correspond to this cycle, in the phase of extinction, the lower boundary of the thermal should rise up to the cloud. We are waiting for corrections and implementation.

Figure_2.png

In the presence of wind, clouds move with the wind along with cloud thermals, this is correct. But, at the same time, the cylinder of the cloud thermal must have a slope from the vertical in accordance with the wind speed. The lower area of the thermal is almost always "behind" the cloud. This has not yet been implemented in MSFS and we are waiting for fixes. The cylinder of the cloud thermal is always clearly formed and has a smaller diameter than the size of the cloud itself. Now in MSFS, large clouds are essentially a cluster of smaller clouds and each of these small clouds generates its own cloud thermal. It seems that there are several thermal cylinders under one large cloud, or there is one "wide" thermal under this cloud, in the body of which there are several pronounced areas with different speeds of vertical air flow. This shouldn't be happening! We are waiting for corrections and implementation. There is no turbulence inside the clouds in SU11! She has to be there! Its presence and activity can be associated with the thickness (height) of the cloud layer and its density. We are waiting for corrections and implementation.

Terrestrial thermals

Starting with SU10, "ground" thermals were introduced, but the developers in no way connected them with the map of "cloud" thermals. I think this is correct and it is not worth asking developers to create such a connection. Terrestrial thermals in reality, in the presence of wind, do not have such a connection. Now in MSFS, terrestrial thermals are formed over the surface of the earth intensely heated by the sun. Their velocity of vertical air flow correctly depends on the angle of the sun's height, which varies from the coordinates of the latitude of the terrain, the day of the year and the time of day (see Figure 3.).

Figure_3.png

I consider the dependence of the vertical air flow velocity in terrestrial thermals on the wind speed implemented in SU11 to be absolutely incorrect (see Figure 4.). The complete absence of wind should correspond to the maximum flow velocity and should progressively decrease the flow velocity with increasing wind speed. At a wind speed of more than 20 kts, the flow velocity is almost zero, the heated air due to turbulence above the ground is mixed with cold air and does not rise above the heating site. We are waiting for corrections.

Figure_4.png

Now in MSFS, the speed of the vertical air flow of terrestrial thermals correctly depends on the height above the ground to a height of about 800-1000 ft, then with increasing altitude it decreases. But, this is correct only up to the height of the base of the clouds, after which it stops. Why does it continue to remain in force 10-20% at altitudes from 20,000 ft and in "space"?! (see Figure 5.). I understand that in the absence of wind (anticyclone), the heated air really warms up the entire height of the atmosphere, but the speed of its rise is negligible. I propose to limit the availability of the vertical air flow velocity of ground thermals with a height of 20,000 ft. We are waiting for corrections.

Figure_5.png

Now in MSFS, terrestrial thermals also depend on the type of surface (water, land, desert, stone, grass (crops), shrubs, trees, villages, cities, etc. But, the problem is that the glider (airplane) determines this type of surface exclusively in the coordinates of its location and in no way "sees" the surrounding area. He defines "particulars" and does not understand "generalities". When flying over different types of surfaces, the glider "sees" constantly changing types of surfaces with different heating values and speeds of vertical air flow. Variometers "go crazy" from such a variety! I understand that scanning the area around the glider and averaging the type of surface is a very difficult and resource-intensive task, but then it is necessary to apply smoothing of the flow rate of ground thermals. We are waiting for corrections and implementation.

Climbing over the slopes of the mountains

This feature has been working since the release of MSFS, but it only works partially correctly. The same problem is that the glider (airplane) "sees" the surface only exclusively in the coordinates of its location and in no way "sees" the surrounding area. He cannot determine the height of the elevation of the slope, cannot distinguish the slope of a small embankment from the slope of high mountains. Therefore, the velocity of the vertical air flow over the elephant does not depend on the height of the slope elevation and can be the same when flying over the slope of the embankment and when flying in the mountains. Also, the speed of the vertical air flow over the elephant is incorrectly determined, depending on the altitude of the flight over this slope (see Figure 6.). Now, even with a wind speed of only 10kts, at an altitude above 40,000 ft, you can get a good flow rate. And at high wind speeds, you can easily climb into "space" even flying over a small embankment! This is very wrong!

Figure_6.png

At the very surface of the slope, the wind slows down, which is now 50%. At an altitude of 800-1000 ft, the wind speed is gaining full force. Accordingly, the speed of the vertical air flow changes proportionally to the wind speed (see Figure 6.). I think that this does not quite correspond to reality, it is desirable to change the braking at the ground to 30% and set the full wind speed at an altitude of already 100-150 ft. I suggest that developers limit the effect of the lifting layer over inclined surfaces to a height equal to two heights above sea level of the underlying surface. At the same time, the velocity of the vertical air flow (both ascending and descending) above the elephant within the height of the layer fades from a maximum to a minimum at the top of the layer. Above the top of this layer there should be no vertical air movements associated with the slope of the earth's surfaces (see Figure 7.).

Figure_7.png

3D-TERMAL visualization

Now in MSFS, visualization of air movement is absolutely meaningless, since there is essentially no air in the simulator and it is not simulated. In the flight model of a glider (airplane), its influence is calculated "as if there is air", but no more. The visualization of the flows is calculated based on the vectors from the vertex to the vertex of the broken lines. With the existing model of vertical flow formation, this in no way corresponds to the vector calculation of visualization lines. In fact, now in MSFS it is just a "beautiful picture" that does not reflect the reality of what is happening, leads to misunderstanding of what is happening and the emergence of many questions not about the visualization error, but an erroneous judgment about the wrongness of the flows. I think the right solution for developers is to completely remove the 3D-TERMAL visualization function in the next update.

 

 

Finally,

Quote

The research was carried out using the program Simvars.exe If you have the SDK installed, then in the folder C:\MSFS SDK\Samples\SimvarWatcher\bin\x64\Release find the file Simvars.exe Instructions for the program can be found here https://docs.flightsimulator.com/html/Samples_And_Tutorials/Samples/VisualStudio/SimvarWatcher.htm If you don't have the SDK installed, then you can download this program Simvars.zip , unpack the archive in any convenient place and run the program Simvars.exe . You can upload my file with the necessary variables to it AMBIENT_WIND_Y.simvars

AND

In the study of the vertical component of the wind over inclined surfaces: 1. The influence of cloud terms is reset to zero by the values of CloudLayerDensity and CloudLayerCoverage equal to zero. 2. The influence of solar heating of the surface is reset by the choice of the place and day of the year for the flight and the minimum solar activity. For example, for the northern hemisphere of the earth, this is the day of December 22. The flight time can be dawn or sunset. Choose a place above the northern slope with a north wind. In the study of the vertical component of cloud thermals: 1. The influence of the wind over inclined surfaces is reset by the choice of the flight location over flat horizontal surfaces, for this flight over the sea or a large lake is ideal. 2. The influence of solar heating of the surface is reset by the choice of the place and day of the year for the flight and the minimum solar activity. In the study of the vertical component from the solar heating of the surface: 1. The influence of cloud terms is reset to zero by the values of CloudLayerDensity and CloudLayerCoverage equal to zero. 2. The influence of the wind over inclined surfaces is reset by the choice of the flight location over flat horizontal surfaces, for this flight over plains without irregularities is ideal.

AND

To measure the vertical component of the wind, you do not have to use the SimVars program. If you fly a glider and use the LXN mod from @CaptnJackBilbo, then you will see the value directly on the LXN display if you set the units to ft/min and multiply by 100.

2022-11-29_141234.png

AND

In SU11, the amount of snow cover DOES NOT AFFECT the value of the vertical component of the wind from the solar heating of the surface! This is also a weather bug in SU 11.

 

FYI,  "CaptnJackBilbo" created a NAV Mod for the DG-808s,   and Discus 2-C.    It greatly extends the functionality and makes it much more useful for gliding tasks.

https://flightsim.to/file/41698/dg808s-lxn-nav-replacement

https://flightsim.to/file/41623/discus-2c-lxn-nav-replacement

I'm using the latest version of the DG808s nav mod from Jack's Github instead of the currnet FS.to version,   because it moves the DG808s to MSFS's new "Glider Category" and thus enables the wing walker / tow plane.    https://github.com/JackBilbo/lxn-dg808s/releases/tag/v0.1.2.1

BTW,   Flew along with SSC today across Chile.   It was really relaxing,   and there were approx. 25 gliders ranging from the DG808s,  to the AS-33ME, to the Discus 2-C.

SSC provides weather presets and flight plans for each flight.  IF everyone hits the "Fly Now" button at the same time,   everyone will have the same weather / clouds / winds.

 

Edited by Waldo Pepper
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Quoting CaptnJackBilbo,

You can configure any aircraft default or addon as MSFS towplane. All you do is edit it's SimObjects/Airplanes/NameOfAircraft/aircraft.cfg file using a texteditor and add or edit the line "isTowPlane=1". For reference check the entry for the official C172 Towplane. As last line you find the isTowPlane-entry. Copy that line to the aircraft.cfg of your desired Towplane and you're good to go for a try.
If your new Towplane has multiple [FLTSIM.XX] Sections in it's cfg for various liveries, make sure to add the line to the right livery. Depending on the power of your tow, you might need to adjust it's charactristrics. That can be done in the ai.cfg file in the [TOWPLANE] section. Also check the official c172 for reference and copy the whole section over to your towplane's ai.cfg. Edit the values at your own risk. I have no idea, what value does what

Link to Jack's Nav Mods on discord, https://discord.com/channels/876123356385149009/1041275752278134824

 

 

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This is pretty intense.  It's clear that there are plenty of users who want the best realism for this sim (I am one of them).  Unfortunately sometimes realism doesn't align with business (which is to be expected in software development).

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I read all of that and the up shot is that Gliding in MSFS as In other SIMs (except Condor and i guess the other one who's name I don't remember) is only for fantasy purposes. Hopefully at some point someone will develop something like CumulusX (I think the guys name is Peter Lurkin or something like that) but other than that I can't see MS or Asobo being too bothered about this niche activity. I've tried it a few time and It's kinda lousy.

Edited by FBW737
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1 hour ago, ryanbatc said:

This is pretty intense.  It's clear that there are plenty of users who want the best realism for this sim (I am one of them).  Unfortunately sometimes realism doesn't align with business (which is to be expected in software development).

That group seems to be an excellent group, and a great source of info for gliders.   To me, gliding is very intense in the first place.   I don't know why but I'm transfixed by the concept of going cross country at 150mph with no engine.  With an advanced glider like the DG-808 you have flaps,  spoilers,  and water ballast.    There is something engaging about constantly managing energy state with your configuration,  while constantly wagering where the lift will be.    The 808 has 3 notches of positive flaps,   then it has a zero setting,  and 3 notches of negative flaps.  It can really haul, man.  

I mean,  I always flew around in gliders by just wandering about wherever I wanted to go,   but flying prescribed tasks is completely different.   Waypoint 2 in Chile today is a perfect example.   It was a big hollow surrounded by mountains,  and reverses course roughly 160 degrees.  Upwind was a pita because I made stupid decisions in that waypoint area.   I actually started cursing myself.   But it makes you learn,  and that is fun.

IF anyone wants to try it,  here's SSC's pln and wpr.  (I'm leaving it up on my google drive for a few days,  then I'm deleting it because I didn't ask for direct permission.   Just putting it here as a courtesy for avsim users who don't' discord and thus would never see it in the first place)  https://drive.google.com/file/d/1IYsrkyS0nFawcBaGxbxUa1lej7YKDl1R/view?usp=share_linkimage.png?width=1908&height=1193

 

 

Edited by Waldo Pepper

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27 minutes ago, FBW737 said:

but other than that I can't see MS or Asobo being too bothered about this niche activity.

If that was true, they wouldn't have added gliders and tried improving the thermals in the first place.

Edited by Tuskin38
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@Waldo Pepper

THANK YOU!!! so much for ( again ) taking the time to bring here a worth of excellent and motivating information about soaring in MFS.

I will surely read all of it and, who knows, even try some task in MFS using one of the tools linked above.

I confess I don't like the "feel f flight" for gliders in MFS. Their response to control inputs isn't the best and I really didn't have tjhe time to find out the quality of the aerodynamics modelng of details like the use of negative flap settings with it's impact in glider performance, as well as the use of ballast. Will try to find ,more about it.

One thing I lknow is that a given simulator whoose name I can't recall doesn't model negative flap aerodynamics at all, and Condor OTOH does it very acceptably ( actually Silentwings does it too in it's best models like the Antares and the G103 ). Will try to give MFS gliders with flaps like the 808 a try, with the Developer windows open to check the variuos parameters, and will have to look at the CFG files too, when I get the chance 🙂

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Flight Simulation is the virtual materialization of a Dream...

CFR = Cat Flight Rules... Flying with a Cat in the glareshield - requires special Certification!

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Well,

I finally got some time to read accross the message posted by Waldo. Again big thanks to Waldo for calling our attention to these studies.

The author of the studies, from that Discord group, surely took his mission "seriously" and tried to gather as much information as possible.

I would love to have time, aand mood, to reach the same conclusions and further investigate the consequences of an incomplete weather model for soaring.

Along my simmer life I used:

- SFS v2 and v3

- FlIGHT UNLIMITED 1 and 3

- FSX and P3D with CumulusX

- Condorsoaring

- SilentWings 

- FlightGear

- X-Plane

- AeroflyFS

and now also MFS.

Of all this sims I continue to prefer Condorsoaring, closely followed by Silentwings, because both while not modelling (not even by far) all types of soaring weather, do their work very acceptably in terms of thermal/convective as well as orographic support, including some rudimentary modelling of wave soaring.

None of the simulators provides frontal/convergence effects, and MFS while showing some nice ideas doesn't look like it's going to allow for it. 

In Soaring, and in Meteorology as a whole we have to take into account not only convection and orographic effects, but also advection and subsidence. Advection can itself create positive vertical air flows, and even strong subsidence like the one provided by the downbursts of convective clouds / thunderstorms can give rise to phenomena like when the outflow meets the surface and creates a line of lift which tained glider pilots can sometimes explore to their advantage...

One aspect of thermals mentioned in that Discord post is the connection between thermals and "good weaher cumulus". It  SHOULD be modeled. Also in MFS the downflow / sinking air surrounding the various possible nucleus bellow a cumulus cloud, or even in blue convection, is not found.

Flying along a line is sometimes more efficient than trying to circle in a "thermal" in MFS, which is completely irrealistic. I believe the flight model or the thermal/convection models fail to properly process situations where the aircraft starts turning near an area of ascending air(?)...

Will try to gather more feedback from the sim...

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Flight Simulation is the virtual materialization of a Dream...

CFR = Cat Flight Rules... Flying with a Cat in the glareshield - requires special Certification!

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15 hours ago, Waldo Pepper said:

That group seems to be an excellent group, and a great source of info for gliders.

They are pretty serious and clearly know what they are talking about. My take away form original post is soaring was more realistic in SU10.

I'm not sure if its the same group. There is another one or perhaps the same on called touching clouds in think. I've flown in a couple of there online races. That was over a year ago. They had thermals baked into their tasks. Those thermals where far more realistic than the thermals provided in SU11. FAR MORE! The tasks were usually a mixture between ridge souring and baked in thermals. Tricky because you could probably fly slower and climb higher on the slopes and ignore the thermals but you would get left behind for sure. Or fly faster and need those thermals to get to the next slope otherwise not make it. But you'd have a chance of keeping up and not disgrace yourself by crossing the finishing line 2 hours after everyone else.

The two observation in the original post that really ring true to me are that the thermal visualization is completely rubbish! And large cumulus clouds are basically all made of a bunch of small generic CU's with there accompanying thermal and development cycle (which IMO in the SIM is way to fast). So the Larger CU's are a mix or small clouds appearing and disappearing in an unsynchronized manner and the corresponding small associated thermals all bunched together following suite. That would seem to me to account for lift just appearing and disappearing under clouds in manner that is totally contrary to expectations for a RW glider pilot.

It seems to me that their gonna have to fix a lot of stuff to make this work to the satisfaction of real experienced glider pilots. Those who just want to get the experience of flying a glider in the game are probably in the big majority and are already satisfied.

Its a game not a simulator!

Edited by FBW737

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In sims you'll usually find me driving the word not allowed cars or flying slow and low.  I like to look at the scenery going by,  while having enough tasks to keep me occupied.   I'd like soaring in MSFS to be 100 realistic,  but I'm happy with what they have so far.    

I can fly slow and low,   not have to listen to an engine,  and there is still the strategy of trying to figure out where your lift will be.  I can see the things they got right,  but I don't have the experience to spot the issues that would  poke an experienced glider pilot in the eye.  😄

Oh well,    I"m going to use it as an enjoyable enough pass time and a chance to learn about real weather behavior patterns.

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3 hours ago, Waldo Pepper said:

In sims you'll usually find me driving the word not allowed cars or flying slow and low.  I like to look at the scenery going by,  while having enough tasks to keep me occupied

Honest to god, I do that in GTA5 sometimes, just walk slowly around in first person or ride a bicycle, because the world is so darn detailed. Or just take a lazy drive through the country side.

There's a ton of details the average GTA player probably wouldn't notice.

Edited by Tuskin38

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On 12/4/2022 at 12:49 PM, FBW737 said:

They are pretty serious and clearly know what they are talking about. My take away form original post is soaring was more realistic in SU10.

I'm not sure if its the same group. There is another one or perhaps the same on called touching clouds in think. I've flown in a couple of there online races. That was over a year ago. They had thermals baked into their tasks. Those thermals where far more realistic than the thermals provided in SU11. FAR MORE! The tasks were usually a mixture between ridge souring and baked in thermals. Tricky because you could probably fly slower and climb higher on the slopes and ignore the thermals but you would get left behind for sure. Or fly faster and need those thermals to get to the next slope otherwise not make it. But you'd have a chance of keeping up and not disgrace yourself by crossing the finishing line 2 hours after everyone else.

The two observation in the original post that really ring true to me are that the thermal visualization is completely rubbish! And large cumulus clouds are basically all made of a bunch of small generic CU's with there accompanying thermal and development cycle (which IMO in the SIM is way to fast). So the Larger CU's are a mix or small clouds appearing and disappearing in an unsynchronized manner and the corresponding small associated thermals all bunched together following suite. That would seem to me to account for lift just appearing and disappearing under clouds in manner that is totally contrary to expectations for a RW glider pilot.

It seems to me that their gonna have to fix a lot of stuff to make this work to the satisfaction of real experienced glider pilots. Those who just want to get the experience of flying a glider in the game are probably in the big majority and are already satisfied.

Its a game not a simulator!

Touching Cloud is the dev who created the DG-808s.   Same dev created "Kinetic Assistant".      KA introduced towplanes and winches to MSFS first,  it also offers carrier catapult and arresting wire functions.    It allows you to record tow plane tracks.

https://msfs.touching.cloud/mods/kinetic-assistant/

KA can inject thermal maps from two sources,  one of which is https://thermal.kk7.ch/   

K7's coverage of certain areas is very extensive.   I should have mentioned it before,  because I do inject from K7 and it is more realistic as far as I can tell.

Screenshot-23.png

That group you flew with was probably Albatross Racing, they use KA.   https://discord.gg/TfvDDhK5

I'm only aware of one other soaring club,  Got Gravel. (who of course,  released the Discus 2-C)  https://discord.gg/U4cFN9A3

Side note/ GG also holds War Bird Wednesdays.  https://discord.gg/y42uyrn3

 

 

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