High-speed transient schlieren system for large wind tunnel
A schlieren and wind tunnel technology, which is used in the testing of machine/structural components, optics, measuring devices, etc. It can solve the problem of beam energy loss, large diameter and focal length of concave mirrors, inability to debug or use transient schlieren systems, etc. problems, to achieve the effect of improving energy utilization and reducing energy loss
Pending Publication Date: 2019-09-06
CHINA ACAD OF AEROSPACE AERODYNAMICS
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Problems solved by technology
The test section of the large wind tunnel is relatively large, and the diameter and focal length of the concave mirror equipped with the schlieren system are relatively large
If the divergence angle of the beam is not controlled so that it just fills the concave mirror, the beam energy will be severely lost, making it impossible to debug or use the transient schlieren system
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[0024] The present invention will be described in detail below in conjunction with the accompanying drawings and examples.
[0025] like Figure 1 to Figure 4 As shown, the present invention is a high-speed transient schlieren system applied to a large wind tunnel, including a laser light source system, a homogenization system, a schlieren system, and a data acquisition and synchronization control system.
[0026] After collimation and aberration elimination, the high-frequency pulsed laser enters the homogenization system, and after passing through the optical homogenization system, a homogenized high-frequency pulsed laser with a certain divergence angle is formed, and stray light is eliminated. The divergent and homogenized laser incident schlieren system is reflected by the first reflector and the first concave mirror and converged into high-frequency pulsed parallel light. The beam continues to transmit through the optical glass and flow field of the wind tunnel test sect...
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Provided in the invention is a high-speed transient schlieren system for a large wind tunnel. The system comprises a laser light source system, a homogenization system, a schlieren system, and a dataacquisition and synchronization control system. A synchronous controller sends a signal to control the laser light source system to emit high-frequency pulsed laser. After the high-frequency pulsed laser passes through the homogenization system, homogenized high-frequency pulsed laser having a certain divergence angle is formed; the homogenized high-frequency pulsed laser enters the schlieren system; the homogenized high-frequency pulsed laser is transmitted to a first concave mirror through a first reflecting mirror and homogenized parallel high-frequency pulsed laser is emitted; after a large wind tunnel flow field, the laser is concentrated by a second concave mirror and then the concentrated laser is reflected by a second reflecting mirror, and the reflected laser is focused at the cutter edge of the schlieren system. And then, the synchronous controller controls a camera to receive a transient schlieren image and the image is stored into a computer. With the homogenization system,the high-frequency pulse laser is dispersed uniformly at a specified angle and stray light is eliminated, so that the energy utilization rate is increased; and thus the transient schlieren technologyis applied to the large wind tunnel.
Description
technical field [0001] The invention relates to a high-speed transient schlieren system. Background technique [0002] The traditional schlieren method is an optical method proposed by Teopler.A in 1864 based on the schlieren instrument to display and measure the inhomogeneous flow field. This method uses the principle that the refractive index gradient of light in the measured flow field is proportional to the airflow density of the flow field, and converts the change of the density gradient in the flow field into the change of the relative light intensity on the imaging plane. The light source of the traditional schlieren is generally a continuous light source, which will produce a time-averaged effect, resulting in the superposition of the flow field wave system structure. Therefore, traditional schlieren can observe and distinguish shock waves, compression waves and other areas with drastic density changes in the compressible flow field, while other flow field informati...
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IPC IPC(8): G01M9/06G02B17/06G02B27/54
CPCG01M9/06G02B27/54G02B17/0605G02B17/0668
Inventor 吴宇阳石伟龙甘才俊赵学军
Owner CHINA ACAD OF AEROSPACE AERODYNAMICS