PO.SCAL.VanGenuchten.Pc
Description
Van Genuchten capillary pressure, [psi]. Se = [1 + (αPc)^n]^(-m).
Syntax
=PO.SCAL.VanGenuchten.Pc(Sw, Swi, alpha, n)Parameters
| Parameter | Description |
|---|---|
| Sw | Water saturation, [fraction]. |
| Swi | Irreducible water saturation, [fraction]. |
| alpha | Fitting parameter, [1/psi]. Typical 0.001-1. |
| n | Pore size distribution parameter, [dimensionless]. Must be > 1. |
SI Unit Version
Lambda Name
PO.SCAL.VanGenuchten.Pc.SIFormula
=LAMBDA(Sw, Swi, alpha, n, LET(
alpha_1psi, PO.UnitConverter(alpha, "1/kPa", "1/psi"),
result_psi, PO.SCAL.VanGenuchten.Pc(Sw, Swi, alpha_1psi, n),
PO.UnitConverter(result_psi, "psi", "kPa")))SI Parameters
| Parameter | Unit | Description |
|---|---|---|
Sw |
- | Water saturation, [fraction] |
Swi |
- | Irreducible water saturation, [fraction] |
alpha |
1/kPa | Fitting parameter, [1/kPa]. Typical 0.001-1 |
n |
- | Pore size distribution parameter, [dimensionless]. Must be > 1 |
How to save as a reusable Excel function
LAMBDA is a built-in Excel feature (Microsoft 365) that lets you create custom functions without VBA. The formula above works as-is when pasted into a cell.
To save a LAMBDA as a reusable named function:
- Go to Formulas → Name Manager → New
- Enter a name, e.g.
PO.SCAL.VanGenuchten.Pc.SI - In Refers to, paste the LAMBDA formula without the trailing invocation
(...) - Click OK
Now use =PO.SCAL.VanGenuchten.Pc.SI(...) anywhere in your workbook.