Method for measuring tollmien-schlichting (T-S) waves in two-dimensional fluid passage based on local pressure

Abstract

The invention discloses a method for measuring tollmien-schlichting (T-S) waves in a two-dimensional fluid passage based on local pressure, and belongs to the technical field of flowing test. The method comprises the following steps of: connecting a circulating water pump and a flow meter to a circulation system of the two-dimensional fluid passage to be tested, establishing a self-circulating flowing system, arranging a pressure sensor in a contact way on the wall surface of the two-dimensional fluid passage, and drilling a hole leading to the interior of the fluid passage in the center of a contact surface; connecting the pressure sensor with a computer data acquisition system; enabling fluid in the fluid passage when entering the two-dimensional fluid passage through a measurement system pipeline to enter in a gradually varied flow form, and forming stable fully developed flow after the fluid passes through a flow stabilization inlet; and recording local pressure signals varied along with time under different flowing Reynolds numbers, and performing processing according to the time history of the local pressure to obtain the natural frequency and the amplitude of the T-S waves. Lower-order to higher-order T-S waves can be measured in any two-dimensional fluid passage, used related equipment is low in cost and convenient to popularize, and a data processing method is simple, intuitive and easy to master.

Description

technical field [0001] The invention belongs to the technical field of flow testing and relates to a new method for measuring T-S waves in a two-dimensional flow path based on partial pressure. Background technique [0002] As the basic unit of reactors and heat exchangers, two-dimensional flow paths with different wall shapes are widely used in the fields of energy, petrochemical, biochemical, and biopharmaceutical. T-S wave, short for Tollmien-Schlichting wave, is a periodic unstable flow behavior in a two-dimensional flow channel when the Reynolds number of the flow exceeds a certain critical value. When the T-S wave appears, the local flow velocity in the flow path presents a sine wave form with a certain amplitude and frequency over time. This frequency is called the natural frequency of the T-S wave. A large number of studies have shown that the heat mass transfer rate in the flow path has a very close relationship with the natural frequency of the T-S wave; if the n...

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Problems solved by technology

However, the method of measuring wall shear stress is usually relatively complicated. Some studies use electrochemical methods to measure, which need to configure electrodes, electrochemical solutions, calibrate the concentration and diffusion coefficient of electrochemical solutions, and calculate the wall shear stress from the diffusion current according to the boundary layer theory. It is not easy to accurately grasp the publicity of shear stress, etc., and the practical application is also limited

[0004] At present, there are almost no reports on the experimental test methods to obtain the T-S wave according to the local pressure and then obtain its natural frequency and amplitude.

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