Device and method for measuring three-dimensional space flow field in sub-span wind tunnel

Abstract

The invention discloses a device and method for measuring a three-dimensional space flow field in a sub-span wind tunnel. Firstly, a tracer particle spreader for spreading tracer particles are connected with a high-pressure air source, the tracer particles are placed in the spreader, and since the tracer particle spreader is connected with the high-pressure air source through a pipeline, the spreading density of the tracer particles is adjusted by adjusting the pressure of the high-pressure air source; four cross-frame CCD cameras are equipped with anti-focal-length perspective control lensesto shoot the flow field, so that clear imaging of a three-dimensional space is ensured; by utilizing lasers, three-dimensional space illumination of the flow field is carried out through the assembledbody light source; a synchronous controller sends out a trigger signal to control synchronous work of the cameras and the laser, and the pressure of the high-pressure air source is adjusted; and after tracer particles in a test area meet the requirements, flow field images are collected through all the cameras, the flow field images shot by the four cameras are reconstructed, and a three-dimensional space flow field of the test area is obtained.

Description

technical field [0001] The invention relates to a three-dimensional space flow field measurement device and method in a sub-span wind tunnel, belonging to the technical field of aerospace experiments. Background technique [0002] Flow field measurement is one of the key issues in the development of fluid mechanics and practical engineering applications. It is not only directly related to the shape design and optimization of streamlined power machinery such as aircraft, automobiles, and high-speed rail, but also restricts the development of fluid mechanics. Especially in the development process of the aircraft, the quantitative measurement of the flow field is an indispensable content. With the development of new aircraft and aerodynamics, people urgently need to solve the flow of complex flow fields with strong unsteadiness, strong three-dimensional space, and strong nonlinearity. Therefore, it is necessary to quantitatively measure the three-dimensional flow field in space...

AI Technical Summary

Problems solved by technology

[0003] Three-dimensional flow field measurement is different from planar measurement, and usually requires the use of multiple cameras for imaging. However, there are still many difficulties and technical problems to be solved in sub-span wind tunnel three-dimensional flow field measurement.

First of all, limited by the structure of the current wind tunnel, the actual space available for the layout of optical equipment is extremely limited, and the installation of the equipment is a big problem; in addition, when imaging with multiple cameras, it is necessary for all the lenses of the cameras to be able to capture Effective area, but the angle between multiple cameras is difficult to adjust, it is difficult to ensure the accuracy of spatial alignment, which affects the accuracy of the final 3D flow field measurement; finally, the tracer particles in the wind tunnel need to ensure followability while ensuring There are particles with suitable concentration and uniform distribution, which is currently difficult to achieve in large-scale sub-span wind tunnels.

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