Latin Alphabet
| A | Area (m2) |
| c |
Concentration - particularly chlorine(mg/l) |
| C | C-value for a pipe (Hazen-Williams formula) |
| D | Diameter |
| ds | Inlet diameter |
| dp | Outlet diameter |
| dt | Time interval (s) |
| e | Specific consumption of electric energy (kWh/m3) |
|
g |
Acceleration due to gravity (9.80665 m/s2) |
| H | Head - elevation of HGL |
| HGL | Hydraulic Grade Line |
| Hp | Pump head, or 'lift' |
| k |
k Chlorine decay rate (day -1) |
| K | Unit resistance of a pipe |
| k h | Demand/load factor |
| L | Length |
| Mld | Megalitres per day |
| n | Rotational speed of pump (rpm) |
| P | Power (usually electric power) (kW) |
| p |
p Local pressure (Pa = N/m2) |
| Qdem | Water consumption (demand) |
| Qlos | Loss of water (usually due to leakage) |
| Re | Reynolds number ( = vD / u ) |
| S | Valve opening (%) |
| t | Time (hh:mm) |
| T | Period of time (s) |
| v | Flow velocity |
| V | Storage/Volume |
| x, y, z | Coordinates |
| Z | Elevation (of ground, or bottom of a reservoir, etc.) |
Greek Alphabet
|
χ |
Local (minor) loss coefficient |
|
η |
Efficiency (%) |
|
λ |
Friction coefficient (Darcy Weisbach formula) |
|
υ |
Kinematic viscosity (m2/s) |
|
ρ |
Density (kg/m2) |
|
ρ |
Angular velocity (s-1) |
|
ω |
Phase angle between voltage and current applied to a load. (Cos φ = Power factor) |