PWC Tree Modle and resulting f coefficent

[jjansman]

Reading Surface Roughness & Porosity | Advanced Modelling PWC | SimScale I see there is the section Tree Model in PWC, but could someone tell me the resulting d (I thought they were zero), f, Forchheimer coefficients), draft coefficient that are used/calculated when using for instance ‘plane tree’ or ‘sycamore’ of 10 and 15m height?

I have a Community account, so I don’t have the option to include porosity base don Tree.

Thanks for your help.

All the best,

Victor

[RicardoParis]

Hi,

The base formulation, as you mentioned, is in that page. There are only 2 parameters missing from that:

• Drag coefficient (C_d): this one is usually 0.2 by default
• Leaf Area Index (LAI). This comes from this database, which contains a huge number of different trees: A Global Database of Field-observed Leaf Area Index in Woody Plant Species, 1932-2011

Cheers

[jjansman]

I don’t see a formula of f as something related to LAI and C_d.
I derived something myself using (I hope correctly) your formula on that page:
f = 2LADCd
but I want to check if my derivation is correct.
Can you help?

All the best,

Victor

[jjansman]

I think the formula is here:

Readyuse-Perforated Plate.xlsx

So my derived formula, is the same as in this spreasheet. Great!!!