The Production of Swirl in Oil and Method of Compensation in Multi-Path Ultrasonic FlowMeter
T. Cousins, B. Griffith
Abstract:
The paper describes a series of tests, which were initially intended to investigate performance of a two plane multi-path meter in the presence of severe swirl. With the two plane design it was clear that detailed data could be produced showing the level of the swirl, its changes with distance along the pipe and even the changes in position of the swirl centre. Most of the work previously on swirl had been conducted at high Reynolds numbers, and the assumptions were made that it takes the same form, possibly until the transition and laminar regions. The tests described range from a Reynolds number of 2000 to just under 1,000,000, thus the data covers the complete transition region and the higher laminar region. Some unusual results were obtained, showing a substantial increase in the production of swirl in the region between 10,000 and 100,000, tailing off as the Reynolds numbers become higher. In this region the swirl appears to be large and to a degree unstable. The paper details the data and also shows the intrinsic ability of the two plane meter to deal with the effects of swirl, even when it is not concentric.
