hello all
how can i simulate annual radiation with respect to clear sky? i gonna simulate radiation on a semi-sphere.
best
Hi @ahad ,
You will have to be specific about what criteria your analysis needs to meet. Do you just need the incident clear-sky radiation or do you also need to account for bounces of radiation off surrounding context surfaces? Do you just need the total annual clear sky radiation or do you need it on an hour-by-hour basis?
Also, are you using the new LBT Grasshopper plugin that was released last week or do you need a solution that uses the Legacy plugin?
@ahad ,
Here’s how it’d done with the new LBT plugin but can I ask why you need annual clear sky radiation? This metric isn’t representative of anything that happens in the real world since every location on earth has at least some cloudy days. Usually, when people do clear sky radiation studies, they are looking at just one day or hour in order to understand the impact of the sunny day on the size, cost, and efficiency of the cooling system.
ClearSkyRad.gh (28.4 KB)
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Dear @chris
I simulated annual radiation that recieved by a semi sphere in variety weathers by LB.now i gonna see what happens when sky is clear. Since 2019, i have working by ladybug to simulate solar radiation on some 3d shapes. I dont realize what is giverning equations of ladybug radiation. Solar radiatiin on sloped surfaces: anisotropic sky are simulated by HDKR model & Perez model & Hey and Davies model &…
Best
Solar radiation on sloped surfaces: isotropic sky are simulated by isotropic sky model too.
according what i said:
Dear @chris
ladybug solar radiation uses isotropic sky or Anisotropic sky?
I still don’t understand why you need annual clear sky radiation and not the annual radiation falling in a typical year but the skies for Ladybug annual radiation simulations are anisotrophic. They use the Radiance gendaymtx function that’s documented here:
http://www.radiance-online.org/learning/documentation/manual-pages/pdfs/gendaymtx.pdf
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I gonna find why (there is a gap between values in the first and end of shape, fig.1) and there is gap in the middle of chart in fig 2. … I guess, it relatives to clearness index and i wanted to see the effect of clearness index and so I simulated wrt clear-sky.
best
Hey @ahad ,
It might be helpful to know that the “LB Import STAT” component will just pick the most accurate clear sky model that it can from what’s available in the STAT file. This will be the ASHRAE Revised Clear Sky (Tau Model) if monthly optical depths are found but it will default to the original ASHARA Clear Sky model if this data isn’t found.
If you need to make sure that you are using only one of these Clear Sky Models, you can use the Honeybee-Radiance Wea components like so:
ClearSkyRad_Custom.gh (29.6 KB)
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Thank you for help…