| 摘要 |
A method and corresponding apparatus for measuring the flow velocity of a fluid in an elongated body by sensing at more than one location along the elongated body, vortical disturbances convecting with the fluid, and correlating the outputs of the variously positioned sensors. The method includes the steps of: providing an array of at least two sensors disposed at predetermined locations along the elongated body, each sensor for sampling the pressure of the fluid at the position of the sensor at a predetermined sampling rate; accumulating the sampled data from each sensor at each of a number of instants of time spanning a predetermined sampling duration; and constructing from the accumulated sampled data at least a portion of a so called k-omega plot, indicative of a dispersion relation for the propagation of acoustic pressures emanating from the vortical disturbances, the constructing of the k-omega plot based on correlating the sampled data provided by at least one of the sensors with the sampled data acquired by at least one other of the sensors, and by autocorrelating the sampled data acquired by each sensor. The method usually also includes the steps of: using a feature extraction technique to identify a convective ridge in the k-omega plot; determining the orientation of the convective ridge in the k-omega plot; and determining the flow velocity based on a predetermined correlation of the flow velocity with the slope of the convective ridge of the k-omega plot.
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