Flow measurement in partially filled pipes using pulsed peak velocity doppler

A method for measuring flow velocity within a pipe comprising:

• positioning a sensor within a body of fluid within said pipe, said sensor comprising an ultrasonic transmitter and an ultrasonic receiver aligned to transmit and receive substantially parallel to said flow;
• repetitively alternately transmitting a pulse from said ultrasonic transmitter and receiving a response with said ultrasonic receiver, said response including Doppler shifted signal returns of said pulse from discontinuities within said flow traveling at said flow velocity;
• said pulse comprising a group of cycles of discrete frequency transitioning to a period of no transmission, said pulse followed by said period of no transmission during which said response is received with said ultrasonic receiver, and said pulse having a predetermined pulse length, said predetermined pulse length referring to a time period encompassing said group of cycles of discrete frequency and not including said period of no transmission;
• said receiving said response with said ultrasonic receiver comprising sampling said response at a predetermined delay from said pulse from said ultrasonic transmitter;
• each said response comprising a summation of reflections resulting from a plurality of pulses of said repetitively transmitted pulses, said summation of reflections comprising reflections from at least two pulses of said plurality of pulses wherein each reflection from said at least two pulses results in a received signal above a noise level;
• assembling a sequence of said receiver response samples in a time domain data set;
• converting said time domain data set to a frequency domain data set;
• finding a peak Doppler shift corresponding to said Doppler shifted signals based on said frequency domain data set;
• and
• computing with a computation means an average flow velocity based on said peak Doppler shift.

A system for measuring fluid flow within a body of fluid comprising:

• an ultrasonic transceiver comprising an ultrasonic transmitter and an ultrasonic receiver, said ultrasonic transceiver generating a sequence of pings, each ping of said sequence of pings comprising said ultrasonic transmitter sending a single pulse within said body of fluid followed by said ultrasonic receiver receiving a single sample of received ultrasonic energy from said body of fluid;
• said single pulse comprising a group of cycles of discrete frequency transitioning to a period of no transmission, said single pulse followed by said period of no transmission during which said ultrasonic receiver receives said single sample of received ultrasonic energy;
• said received ultrasonic energy comprising a plurality of Doppler shifted signals from objects flowing with said fluid, said Doppler shifted signals resulting from said sequence of pings;
• said sequence of pings having a fixed time between sequential ping s of said sequence of ping s, said fixed time being shorter than a time required to transmit a pulse and receive a resulting reflection from an object at a maximum range from the transceiver;
• said ultrasonic receiver generating a time domain signal sequence from said received samples of said sequence of pings;
• a time domain to frequency domain signal converter producing a spectral response of said time domain signal sequence;
• a detection means for finding a peak Doppler shift within said spectral response of said time domain signal sequence, said peak Doppler shift resulting from said Doppler shifted signals reflected from objects flowing with said fluid;
• and
• a computation means for finding an average flow velocity based on said peak Doppler shift.