欧兰公司主站 欧兰公司双线路主站
北京欧兰科技发展有限公司




 
no-img
BOS imaging of a thermal flow
 

Background Oriented Schlieren: BOS Imaging

Schlieren imaging is based on the deflection of light beams crossing gradients of the index of refraction in a transparent medium. These index of refraction gradients can be introduced by density discontinuities in a fluid or in mixing processes of different optical materials. Schlieren is a line-of-sight imaging technique allowing only a qualitative flow visualization.
In conventional Schlieren setups a collimated light beam is deflected across a knife-edge causing a change of light intensity in the direction perpendicular to the knife-edge. A direct quantification of the light deflection is not possible. The digital version of Schlieren imaging is called Background Oriented Schlieren (BOS) or Synthetic Schlieren based on Digital Image Correlation (DIC). In practice, only a random dot pattern in the background of the flow is imaged with a high resolution camera before and during the test. By comparing the two pictures (or more precisely correlating the two patterns similar to the image correlation in PIV) the local displacement of the background pattern can be used to provide lateral information on path-integrated refractive index variations. Compared to the conventional knife-edge Schlieren method, BOS can visualize large scale flow phenomena and measures the optical flow distortion in form of a digital vector map. For 2-dimensional or axisymmetric flows, BOS provides the potential to measure absolute 3- dimensional density and temperature fields.

 
 

Related Products

 
 
 
 
 
 
 
 
 
基于博卡先锋SiteEngine构建
北京欧兰科技发展有限公司 版权所有 电子邮件:info@oplanchina.com oplan@263.net,
联系电话:010-62623871, 62616041,62612809 传真:010-59713638
地址:北京市,海淀区,上地十街1号,辉煌国际中心1号楼1006室 邮政编码:100085京ICP备07038319号-1
Processed in 0.038 second(s), 3 queries