Layered Synchronous Three-dimensional Particle Image Velocimetry Method and Device

Abstract

The invention relates to the technical field of hydromechanics model tests, and provides a particle picture speed measuring technique which is efficient, reliable and strict and synchronous in measurement of different sections. According to a lamination synchronous three-dimensional particle picture speed measuring method, incident multi-color lasers are dispersed to light sources of different colors by a triple prism light splitting device, and meanwhile the light sources illuminate to a testing area; an illuminated particle picture presents different color characteristics in different sections; a set of charge coupled device (CCD) video cameras are arranged near the testing area, an optical filter in a certain color is added to the front of a lens of each video camera, the colors of the optical filters are matched with those of the light sources, so that the video camera can only shoot the section with the corresponding color; and all the video cameras work simultaneously, particle pictures on different sections are obtained simultaneously, two-dimensional particle picture analysis is conducted on each section, relative analysis is conducted on pictures among different sections, and three-dimensional flow field information is obtained. The method is mainly applied to testing and measuring of hydromechanics models.

Description

Technical field [0001] The invention relates to the technical field of fluid mechanics model testing, in particular to a flow field particle image flow velocity measurement technology, in particular to a layered synchronous three-dimensional particle image velocity measurement method. Background technique [0002] The measurement of flow field is an important technical means of fluid mechanics experiment, and it is very important in the research of aerodynamics and hydrodynamics. Particle Image Flow Velocity (PIV) is a fluid dynamics velocimetry method developed in the late 1970s. Its principle is to spread a large number of tracer particles in the flow field to follow the movement of the flow field, and use a laser to provide a light source to illuminate The flow field is cross-section, and a digital camera is used to take a picture of the flow field. Finally, the velocity distribution is obtained by cross-correlation calculation of the two or more frames of particle images. PI...

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Problems solved by technology

The above-mentioned three-dimensional PIV technologies all have their own limitations. For example, the measurement section thickness of the volume perspective method is generally small, and the maximum cannot exceed more than ten millimeters, otherwise the overlapping and mismatching of particles will be very serious; the holographic image method is limited by the holographic technology. , the current cost is very high, and the corresponding algorithm is not mature enough, so it is difficult to be widely used; and the slice scanning method can obtain richer three-dimensional flow field data by using the existing two-dimensional PIV algorithm. However, due to the scanning time period, Different sections cannot be measured synchronously, and in fluid mechanics analysis, flow space correlation calculations strictly require simultaneous acquisition of flow velocity data at different measurement locations

In addition, the periodic scanning motion of the sheet light source complicates the mechanical design and the synchronous control with the camera, which brings difficulties to popularization and application.

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