Non-Nulling Gas Velocity Measurement Apparatus And Performing Non-Nulling Measurement Of Gas Velocity Parameters

patent description

(1) Disclosed is a non-nulling gas velocity measurement apparatus for non-nulling measurement of gas velocity parameters, the non-nulling gas velocity measurement apparatus comprising: a non-nulling pitot probe comprising: an aerodynamic flow head comprising a plurality of entrant apertures that comprises a central entrant aperture and a plurality of peripheral entrant aperture arranged radially from the central entrant aperture, such that the entrant apertures receive a gas flow from a gas source; an entrant body tube disposed on the aerodynamic flow head; an extensor body tube disposed on the entrant body tube such that the entrant body tube is interposed between the aerodynamic flow head and the extensor body tube, such that extensor body tube is arranged at an oblique angle to the entrant body tube; and a plurality of pressure channels disposed in the aerodynamic flow head, the entrant body tube, and the extensor body tube, such that each entrant aperture is separately and independently in fluid communication with one of the pressure channels, and each pressure channel independently receives and communicates the gas flow as stagnant gas from the entrant aperture of which the pressure channel is in communication; and a plurality of gas valves such that each gas valve: is in fluid communication with a different entrant aperture of the non-nulling pitot probe via a different pressure channel; receives stagnant gas from the respective entrant aperture; receives a reference gas; receives a valve control signal; and produces a valve-selected gas based on the valve control signal, the valve-selected gas consisting essentially of the reference gas or the stagnant gas; and a plurality of differential pressure transducers, such that each differential pressure transducer: is separately and independently in fluid communication with a different gas valve, and that gas valve communicates the valve-selected gas to the differential pressure transducer; receives the valve-selected gas from the gas valve; receives the reference gas at a reference gas pressure; compares a pressure of valve-selected gas to the pressure of the reference gas; and produces a differential pressure signal from comparison of the pressure of the valve-selected gas to the reference gas pressure.

(2) Disclosed is a process for performing non-nulling measurement of gas velocity parameters, the process comprising: receiving, by an analyzer, a zeroth differential pressure signal, first differential pressure signal, a second differential pressure signal, and third differential pressure signal; producing a zeroth calibrated pressure from the zeroth differential pressure signal, a first calibrated pressure from the first differential pressure signal, a second calibrated pressure from the second differential pressure signal, and a third calibrated pressure from the third differential pressure signal; removing a dependence of a reference gas pressure of a reference gas from the zeroth calibrated pressure, the first calibrated pressure, the second calibrated pressure, and the third calibrated pressure to produce, respectively, a first adjusted pressure, a second adjusted pressure, and a third adjusted pressure; combining the first adjusted pressure, the second adjusted pressure, and the third adjusted pressure to obtain a pseudo-dynamic pressure scalar; individually normalizing the first adjusted pressure, the second adjusted pressure, and the third adjusted pressure with the pseudo-dynamic pressure scalar to produce, respectively, a first reduced pressure, a second reduced pressure, and a third reduced pressure; determining a real dynamic pressure from the first reduced pressure, the second reduced pressure, and the third reduced pressure; determining a yaw angle or a pitch angle of the gas flow from the first reduced pressure, the second reduced pressure, and the third reduced pressure; and determining velocity of the gas flow from the real dynamic pressure to perform non-nulling measurement of gas velocity parameters.