0
Specific speed (Ns) is a non-dimensional design index used to classify pump impellers as to their type and proportions.
It is defined as the speed in revolutions per minite at which a geometrically similar impeller would operate if it were of such a size as to deliver one gallon per minute against one foot of head.
The formula used to determine specific speed is
Where
N = Speed of Pump in RPM
Q = Capacity in gpm at the best efficiency point
H = Head per stage in feet at the best efficiency point
The specific speed determines the general shape or class of the impeller. As the specific speed increases, the ratio of the impeller outlet diameter, D2, to the inlet or eye diameter, Di, decreases. This ratio becomes 1.0 for a true axial flow impeller.
Low specific speed - Radial flow Impeller.
Medium specific speed - Mixed flow Impeller.
High specific speed - Axial Flow Impeller.
Still curious? Ask our experts.
Chat with our AI personalities
Professor
Vivi
DevinAdd your answer:
Earn +20 pts
What is a significance of a name?
It helps to identify specific things!
What is a real-world example of using vectors?
An airplane flying in a specific direction at a specific speed.
What is the significance of change in position over change in time?
To different individuals, it may or may not have any significance. The quantity is typically referred to as "speed", and you're free to decide for yourself whether it has any relevance in your life.
What is 1755 km in hours?
You can't convert length to time - unless you have a speed problem, in which case you have to assume a specific speed as the "conversion factor".
How do you measure speed of a paper plane?
You should time it until it stops and check out how long it will cross in that specific amount of time. Speed = Time --------------- Distance
