# Porosity

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Porosity, abbreviated as P, a dimensionless number, is the ratio between the pore volume of a substance and its total volume.  Porosity of a measure of a rocks capacity to store fluids.

### Porosity formula

$$\large{ P = \frac {V_v} {V_t } }$$

$$\large{ P = \frac { v} { v_s} }$$     (seepage velocity)

Where:

$$\large{ P }$$ = porosity

$$\large{ v }$$ = Darcy velocity or flux

$$\large{ v_s }$$ = seepage velocity

$$\large{ V_t }$$ = total volume

$$\large{ V_v }$$ = voids volume

Solve for:

$$\large{ V_t = \frac { V_v} { P} }$$

$$\large{ V_v = P \; V_t }$$

Tags: Equations for Volume