The annular space simulates an orifice at high flow rates, and turbulent gas flow then depends predominantly on the density of the gas and follows the Graham’s law. Physical characteristics of the gas – because the annular space is tubular at low flow rates, flow is laminar and viscosity determines the gas flow rate and hence follows the Poiseuille’s law.Īt low flow diameter is less than length – tubular, so laminar flow. Iv) The tube is positioned vertically with smallest diameter end of the tapered flow tube at the bottom. I) A uniformely tapered flow tube ( Thorpe’s tube), This rotameter consists of three elements:. Rotameter is a particular kind of flowmeter based on variable area (variable orifice) and constant pressure Principle.
