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Old   August 26, 2004, 12:34
Default Drops evaporation
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Does somebody have an information on how does the number of droplets in a parcel affect the solution convergence and accuracy?

E.g. I have 20 parcels by 25402 drops of n-heptane in each. Density = 684 kg/m3. Initial velocity = 100 m/s. Drops diameter = 30e-06 m. Can this by itself cause solution divergence?

PS. I work on v3.150A.


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Old   August 27, 2004, 14:56
Default Re: Drops evaporation
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Usually, I have problem of convergence when the droplet properties are badly defined: especially density(T), Hv(T) and Ps(T). When correctly calibrated it works (notwithstanding, be carefull to the boiling model if you use the spray model)
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Old   August 30, 2004, 03:29
Default Re: Drops evaporation
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Julie, you should use "enough" parcels in your simulation. "Enough" must usually be established by trial and error. Test, say, three different amount of parcels and see if the results change.

The number of drops in a parcel is the outcome from the mass balance computation in your droico (if you are using one).

So all in all, you should worry about the number of parcels you use and let the code "worry" about the amount of drops in a parcel

I have never observed problems with having either 0.0234 drops / parcel or 1268 drops / parcel; the amount of drops in a parcel is purely a numerical issue.
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