Method and apparatus for measuring fluids with a turbine flow meter, through a turbine flow meter without reference to viscosity

摘要

A method and apparatus without knowing the viscosity of the fluid, measuring the volume flow rate through the duct. Dual rotor turbine volumetric flow meter (10) is operatively connected to a duct through which fluid flows. Dual rotor turbine (10), has a rotor temperature gauge (16), and the first (18), the second rotor (20), the first rotor (18) and the rotor of the second (20) One is to have a non-linear response to fluid flow out of at least. Dual rotor turbine volumetric flow meter (10) is calibrated by deriving (32) the number Roshuko / Strouhal number curve. During the measurement, the rotor frequency of the second rotor and the first frequency is determined. Frequency ratio is derived by dividing the frequency of the rotor first rotor second frequency, Roshuko speed is calculated in combination with the frequency ratio next. By using Roshuko number / Strouhal number curve with (32) the number Roshuko the combination, the Strouhal number is derived combination. Volumetric flow rate is calculated using the Strouhal number combination.