Centrifugation, pressure effects velocity

Extensive application of the theory has been made in treating pressure effects on velocity centrifugation. If w denotes angular speed, sp the sedimentation coefficient at pressure p, ra the radius of the meniscus, x = (r/ra)2, the usual representation of pressure effects leads to the relation (10),... 

In addition to the foregoing standard devices for measuring the flow of fluids, there exist a number of supplementary devices less amenable to exact theoretical analysis but worthy of brief mention. One of the simplest for measuring flow in a pipeline is the elbow meter, which consists of nothing more than piezometer taps at the inner and outer walls of a 90° elbow in the line. The pressure difference, due to the centrifugal effects at the bend, will vary approximately as the velocity head in the pipe. Like other meters, the elbow should have sections of straight pipe upstream and downstream and should be calibrated in place [32],... 

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