Meaning of W_fuel

[r-broek]

In the Thermal degradation model, section 17.1.2, a quantity W_fuel (Eq. 17.24) is defined. It seems to represent the molecular weight of something, but I'm not sure which component. At first I thought it was the molecular weight of the fuel gas, however, would that not simply be 12(x−x′) +y+16(z−z′)? Could anyone clarify?

[mcgratta]

I'll take a look.

[mcgratta]

Yes, that seems confusing. W_fuel in this context is referring to the original dry vegetation. It is assumed that the dry vegetation is made up of a single effective molecule, whose molecular weight is W_fuel. I'll change the subscript to "veg".

[r-broek]

Ah that makes sense. As a follow-up question: does the $1-\nu_{ash} \nu_{char}$ term then account for the molecular weight of the inorganic compounds $A$?

[mcgratta]

Yes, and $\nu_{\rm ash}$ is the fraction of char mass that remains as ash.

[r-broek]

I think I understand it now, thanks a lot!