This online script calculates the operating discharge and head for a given hydraulic pump-system combination.
The following hydraulic variables are specified as input:
Pipe diameter D
Pipe length L
Friction factor f
Upstream reservoir elevation E1
Downstream reservoir elevation E2
Entrance loss coefficient Ke
Exit loss coefficient KE
Sum of bend loss coefficient(s) [one or more bends] Kb
The script uses these values to calculate the values of a and b in the system curve H = a + bQ2
The pump head-discharge relation is specified in one of two ways:
Theoretical: An equation of the
form H = c - dQ2, where c and d are specified as input; or
Practical: The number of values N in the arrays of pump head H and discharge Q relation (pump curve),
followed by the array of H and Q.
Please note that the Q array (the independent variable) should increase monotonically, from small to large.
The script calculates the intersection of the two curves in the H-Q plane, and reports the corresponding Q and H as operating discharge and head.