PIV tracer particle wall spreading device

Abstract

The invention discloses a PIV tracer particle wall spreading device and belongs to the field of flow measurement in the near wall area. The device comprises a particle generator, a high pressure softpipe and a wall particle injection device, wherein the particle generator comprises an air inlet, a particle outlet and a stirrer, the particle outlet of the particle generator is connected with the wall particle injection device through the high pressure soft pipe, the wall particle injection device has a chamber, a particle injection hole and a thin cover plate, the chamber is provided with theparticle injection hole, the particle injection hole is provided with a pressure sensor at the downstream, and the thin cover plate is arranged above the chamber. The device is advantaged in that a problem that the existing PIV tracer particle spreading method cannot make PIV tracer particles enter the boundary layer or the supercavitation is solved, injection of the PIV tracer particles into thenear wall region is achieved, and the good technical support is provided for research of the supersonic or hypersonic boundary layer transition and ventilated supercavitation flow mechanism.

Description

technical field [0001] Embodiments of the present invention relate to the field of flow measurement in a near-wall region, and in particular to a wall spreading device for PIV tracer particles. Background technique [0002] Most of the traditional flow velocity measurement instruments can only perform single-point measurement, and they are contact measurements, which cannot perform undisturbed measurement of the two-dimensional flow field in the entire area. With the rapid development of computer technology and image processing technology, PIV (Particle Image Velocimetry, Particle Image Velocimetry) has broken through the traditional single-point measurement limitation, and can measure the two-dimensional velocity distribution on a cross-section in the flow field instantaneously without contact, and has a relatively High measurement accuracy. Therefore, PIV technology is widely used in the study of fluid mechanics of airflow and water flow. [0003] For underwater moving o...

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Problems solved by technology

When PIV technology is used for full-field velocity measurement, the flow measurement in some near-wall regions, such as the laminar boundary layer, the boundary layer in the transition region, and the interior of the supercavity, etc., adopts the conventional mainstream region tracer particle seeding method, that is, The tracer particles are sown in the incoming flow area of ​​the upstream section. Due to the lack of sufficient material and energy exchange in the boundary layer or the flow inside the supercavity, it will be difficult for the tracer particles to enter the interior of the near-wall region of the test, making it difficult to calculate the relevant velocity field. question

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