ABSTRACT
The increase in velocity at the restriction causes the static pressure to decrease at this section, and a pressure difference is created across the element. Most of the discussion is devoted to the rotameter, because the number of installed rotameters and movable vane meters is large relative to the number of weirs and flumes, and because the movable vane is often used simply as a flow indicator rather than as a meter. For many small rotameters, integrated flow controllers are offered; these hold the pressure drop and the flow setting constant, even with changing upstream or downstream pressure. Not including the special case of water meters, which are described later, the main performance characteristics are: There are two approaches described in the current literature for analyzing axial turbine performance. Within application constraints, the primary objective is usually to optimize the overall mechanical stability and fit in order to achieve good repeatability performance.
