Vortex street cross-correlation flowmeter based on micro transient pressure sensors

Abstract

The invention relates to a vortex street cross-correlation flowmeter based on micro transient pressure sensors. The micro transient pressure sensors are taken as measuring elements, each transient pressure sensor comprises a probe and a transmitting amplifier, each probe contains a sensitive element and a pressure guiding tube, each sensitive element is located at the tail end of the correspondingpressure guiding tube, and each pressure guiding tube is connected with a measuring pipeline; the length of each pressure guiding tube is not more than tube wall thickness and is as short as possible, and the diameter of each pressure guiding tube is consistent with the diameter of a pressure guiding hole of the corresponding probe, thereby guaranteeing that a cavity of each pressure guiding tubeis small enough; two transient pressure sensors which are the same are adopted for acquiring a vortex-induced fluctuating pressure signal, and distance l between the two sensors is less than wave length of one vortex street signal; and a vortex street signal acquired at the two transient pressure sensors is processed by utilizing a cross-correlation method, thus obtaining a vortex street convection velocity, calibrating and obtaining an inflow velocity as a convection velocity and the inflow velocity keep a linear relation, and then obtaining a measured value of the average flow rate.

Description

technical field [0001] The invention belongs to the field of flow measurement, and relates to a vortex street cross-correlation flowmeter. Background technique [0002] Karman vortex street is an important phenomenon in fluid mechanics. When the fluid flows through a bluff body, vortex shedding occurs alternately on both sides of the bluff body at frequency f, and a vortex street is formed in the wake. The flow rate can be realized by measuring the frequency of vortex street shedding. Measurement. Vortex streets are widely found in chemical, aerospace, petroleum and other industrial fields. Accurate measurement of vortex flow field flow is of great significance for process control and production safety of industrial production. [0003] There are various methods for measuring the fluid flow in the vortex flow field, such as conductivity probes, fiber optic probes, piezoelectric sensors, etc. Probe sensors are simple in method and low in price, but because they invade the f...

AI Technical Summary

Problems solved by technology

Piezoelectric sensors also belong to intrusive measurement, and their ability to resist vibration interference signals is poor, so that the vortex flow measurement is distorted; only the frequency information of the signal is obtained in the signal acquisition, and the real flow field fluctuation information is hardly reflected. The phenomenon of vortex shedding, divergence, and separation in the eddy current field will cause dynamic fluctuations in the pressure in the flow field, and changes in internal flow conditions play an important role in improving measurement accuracy.

In addition, the current measurement methods often have the problem of relatively small range in the measurement of small-caliber vortex flow field, resulting in low measurement accuracy, narrow measurement range, and reduced practical value.

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