Abstract
Rotating vane type flow meter has been widely used to measure the water quantity to each household through water supply network. Depending on the water quantity, three types of meter, single case type for small, double case type for medium, and vertical type for large amount, are used. All type devices consist of vane rotor and it is set across the water piping. The rotor rotation is supposed to be proportional to the total flow quantity. Since this is a measuring device, it must be reliably accurate for defined usage condition, which is usually very strict and wide. In order to design such device, knowledge on the flow condition in them is essential. Here we used Hydrogen Bubble Flow Visualization technique, and obtained complete understanding of the flow character for the double case flow meter.
