Air Flow Bench - Air Pump

Air Pump

The air pump used must be able to deliver the volume required at the pressure required. Most flow testing is done at 10 and 28 inches of water pressure (2.5 to 7 kilopascals). Although other test pressures will work, the results would have to be converted for comparison to the work of others. The pressure developed must account for the test pressure plus the loss across the metering element plus all other system losses. The greater the accuracy of the metering element the greater is the loss. Flow volume of between 100 and 600 cubic feet per minute (0.05 to 0.28 m³/s) would serve almost all applications depending on the size of the engine under test.

Any type of pump that can deliver the required pressure difference and flow volume can be used. Most often used is the centrifugal dynamic type, which is familiar to most as a vacuum cleaner. Multistaged axial-flow fan types and positive displacement types (piston and rotary) could also be used with suitable provisions for damping the pulsations. The pressure ratio of a single fan blade is too low and cannot be used.