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Icing conditions

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Icing conditions

Postby legoboyvdlp » Tue Jul 04, 2017 8:53 am

Hey there,
I have developed a quite advanced simulation of icing for the A320Family. However, I'm not so certain about my icing conditions. At present I use '
Code: Select all
var spread = temperature - dewpoint;
   if((spread < maxSpread and temperature < 0) or (temperature < 0 and visibility < 1000)) { # freezing fog or low temp and below dp
      setprop("/systems/icing/icingcond", 1);
   } else {
      setprop("/systems/icing/icingcond", 0);
   }
.

However, I am not convinced about whether this accurately simulates icing conditions. I know that in clouds below 10 TAT, you should be turning on the anti-ice, at least for the A320 (by SOP).

I was wondering if there is a simple way to get the altitude and position of Advanced Weather clouds, or if there are any better conditions that I could put in this if satement?

By the way, the freezing fog definition is according to Wikipedia, where it says that in the UK fog is defined at 1000m visibility or less. Should I increase that to around 2000m, so it includes freezing mist?

Jonathan
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Re: Icing conditions

Postby BEL ISAAK » Tue Jul 04, 2017 11:18 am

I've been searching for this too, as I am doing the same for the 777. Didn't find it yet, so if there's a solution, I 'm happy to hear about it too!
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Re: Icing conditions

Postby legoboyvdlp » Tue Jul 04, 2017 12:10 pm

You may use my code at www.github.com/it0uchpods/A320Family for the 777.
As far as I know, there is icing code in Nasal/icing.nas and /PitotIcing.nas (not hooked up to PFD yet). There is also some code in -main.xml.
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Re: Icing conditions

Postby Thorsten » Tue Jul 04, 2017 2:30 pm

You may have tried this already - but can't you simply use the current visibility? The larger AW clouds and layers should reduce visibility when you are inside the cloud (and the smaller ones are unlikely to lead to icing...)
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Re: Icing conditions

Postby legoboyvdlp » Tue Jul 04, 2017 5:00 pm

Sure. That's just about what I would need; thanks :)

Edit: I take it that is "/environment/visibility-m", as defined in local-weather.nas? I'll continue assuming that is the case.
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Re: Icing conditions

Postby Thorsten » Tue Jul 04, 2017 5:07 pm

Yes, that should be it. If that doesn't give you what you need, I'll have to take a look whether we can provide something else.
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Re: Icing conditions

Postby legoboyvdlp » Tue Jul 04, 2017 6:06 pm

I can confirm that the property reduces when we are in cloud, so we should be in business :D
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Re: Icing conditions

Postby BEL ISAAK » Wed Jul 05, 2017 5:06 pm

For me that property doesn't reduce in clouds. It 's fixed at 25000 below about 2500-3000ft AGL and above that increases with altitude (and decreases when descending), but doesn't decrease while flying through clouds. Advanced weather is on, live data, winds aloft waypoints and realistic visibility.
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