Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Hydraulic gradient ( $$i$$ ) (dimensionless number) is the change in height (pressure) to length.

$$hydraulic \; gradient \;=\; \frac { pressure \; head \; at \; point \; 1 \;-\; pressure \; head \; at \; point \; 2 } { length \; of \; column }$$

$$i = \frac { h1 \;-\; h2} { l}$$

Where:

$$i$$ = hydraulic gradient

$$h1$$ = pressure head at point 1

$$h2$$ = pressure head at point 2

$$l$$ = length of column

Solve for:

$$h1 = i l \;+\; h 2$$

$$h2 = h1 \;-\; i l$$

$$l = \frac { h1 \;-\; h2} { i}$$