Three-dimensional laser alignment positioner for particle image velocimetry

Abstract

The invention discloses a three-dimensional laser alignment positioner for a particle image velocimetry and belongs to the technical field of fluid dynamic experiments. The positioner comprises a three-dimensional coordinate adjusting frame and a laser sheet optical correction system. The three-dimensional coordinate adjusting frame comprises a Z-direction coordinate frame, a Y-direction coordinate frame, an X-direction coordinate frame, a front positioning cross ruler, a rear positioning cross ruler, a rotating substrate and a base; and the laser sheet optical correction system comprises two upper and lower laser sheet optical correction boards with the same structure, a focusing ruler, a photoelectric detection board and a photoelectric indicator. By using the three-dimensional coordinate adjusting frame, the positioner can accurately determine the position of a testing plane, realizes the overlap of three surfaces of a flow field testing plane, a laser sheet light surface and a camera shooting surface through the laser sheet optical correction system, automatically detects the overlap ratio through a photoelectric detection device, and avoids human errors brought by the conventional visual inspection and other experimental calibration methods. Therefore, the calibration process of the particle image velocimetry is simpler and more standard and accurate.

Description

technical field [0001] The invention relates to an instrument for three-dimensional laser measurement and positioning of a particle image velocimeter, belonging to the technical field of fluid mechanics experiments. Background technique [0002] Particle Image Velocimetry (PIV for short) is a non-contact flow field measurement technology based on cross-correlation analysis of flow field images, which can realize undisturbed measurement of two-dimensional and three-dimensional flow fields, and is a powerful tool for modern flow field testing. It is an important tool for studying the flow field structure, and has been widely used in many fields such as fluid mechanics, biomechanics, aerospace, marine hydraulics, etc. The equipment related to PIV technology is sold with standard commercial configuration products. Many domestic research institutions have purchased PIV equipment, mainly including lasers, image acquisition cameras (CCD), synchronization controllers, particle gener...

AI Technical Summary

Problems solved by technology

In actual use, the prerequisite for obtaining an accurate velocity field is to ensure that the plane to be measured in the flow field, the smooth surface of the laser sheet, and the shooting plane of the CCD camera coincide with each other. PIV manufacturers provide a simple calibration plate to achieve the above purpose. In fact, it is used The empirical method of naked eye observation, such as the positioning of the board, identification of marking points, etc., is time-consuming and cumbersome. There are many uncertainties in practice, which makes the measurement results have large human errors. This uncontrollable error is impossible in fine measurement. tolerated

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