Method and system for characterizing pulsatile flow in a vortex flowmeter
AssigneeThe Foxboro Company
InventorWade Mattar
Life of this patent
Estimating the term…
Abstract
A method for determining the pulsatile flow characteristics in fluid flow driven by a periodic pressure disturbance includes the step of evaluating the spectrum of a signal representative of the vortices generated by a vortex flowmeter. Because of the periodic pressure disturbance, the signal is an FM signal in which a carrier, having a frequency corresponding to the vortex-shedding frequency in the absence of pulsating flow, is modulated by the periodic pressure disturbance. The pulsation frequency and amplitude are then estimated on the basis of the separation between adjacent sidebands of the spectrum of the FM signal and the relative amplitudes of the sidebands.
Claims39
A method for estimating pulsatile flow characteristics in a fluid flow having a pulsatile component, said method comprising the steps of
- generating a flowmeter signal having a frequency modulated by the pulsatile component,
- obtaining a measured spectrum of the flowmeter signal,
- estimating the pulsatile flow characteristics on the basis of the measured spectrum.
A vortex flowmeter comprising:
- a housing,
- a vortex-shedding structure mounted on said housing and exposed to a fluid flow, said vortex-shedding structure generating vortices at a vortex-shedding frequency indicative of a flow velocity of the fluid flow,
- a transducer proximate to said vortex-shedding structure for detecting the vortices shed by said vortex-shedding structure and generating a frequency modulated flowmeter signal therefrom, said frequency modulated flowmeter signal being modulated by a pulsatile component of the fluid flow, said pulsatile component having pulsatile flow characteristics,
- spectrum analyzer means for obtaining a measured spectrum of the frequency modulated flowmeter signal, and
- pattern recognition means coupled to the spectrum analyzer means for estimating the pulsatile flow characteristics on the basis of the measured spectrum.
A vortex flowmeter comprising:
- a housing,
- a vortex-shedding structure mounted on said housing and exposed to a fluid flow, said vortex-shedding structure generating vortices at a vortex-shedding frequency indicative of a flow velocity of the fluid flow,
- a transducer proximate to said vortex-shedding structure for detecting the vortices shed by said vortex-shedding structure and generating a frequency modulated flowmeter signal therefrom, said frequency modulated flowmeter signal being modulated by a pulsatile component of the fluid flow, said pulsatile component having pulsatile flow characteristics,
- a spectrum analyzer for obtaining a measured spectrum of the flowmeter signal, and
- a pattern recognition module coupled to the spectrum analyzer for estimating the pulsatile flow characteristics on the basis of the measured spectrum.
Dependencies are inferred from the claim text.