Impeller Specific Speed­ (Ns)

The term impeller specific speed is used to­ clas­sify impellers of various types based on their performance. Specific speed is defined as that speed at which a geometrically similar pump would deliver one unit of flow to one unit of head. Input values for Flow and Head t­hat correspond to the the pump performance at optimum (or best) efficiency point. In this example, calculate the specific speed in either Metric or US units.