实验流体力学2025，Vol.39Issue(4)：9-18,10.DOI:10.11729/syltlx20250016
基于全息聚焦纹影技术的三维流场测量
Research on holographic focusing schlieren imaging for three-dimensional flow field measurement
摘要
Abstract
Flow field display and measurement technology is the key technology in the study of fluid mechanics.Now most of the methods need to combine multi-view recording or tomography to realize three-dimensional measurement.This paper introduced the holographic focusing schlieren technique based on digital image reconstruction method.This technique uses digital holographic technology to record the wavefront in the focusing schlieren imaging system,and uses the scalar diffraction theory to reconstruct the focusing schlieren images of different positions in the measurement area.This realizes the display and measurement of the three-dimensional flow field structure.Based on the pre-developed holographic focusing schlieren technique,this paper provides a quantitative analysis of the three-dimensional flow field imaging quality by holographic focusing schlieren.The parallel double jets and single jet imaging experiments with different defocusing degrees were carried out.Firstly,parallel double jets 30 mm and 60 mm out of focus were measured,and a single hologram was used to obtain the focusing schlieren of the two jets at the same time.The reconstruction of focusing schlieren images has the same imaging effect as the conventional focusing schlieren images with the same first class field transient at the corresponding position,and the imaging plane did not need to be moved.The three-dimensional measurement capability of holographic focusing schlieren technique is verified.Secondly,the imaging capability of this technique is quantified by defocusing distance,and single jets at different positions are measured within the range of 0-120 mm defocusing distance.The flow field outline in the reconstruction image was clear,and the details of the flow field were consistent with those in the traditional focusing schlieren image with the same transient field.The result further verifies the accuracy of 3D flow field information restoration by holographic focusing schlieren technique.The holographic focusing schlieren technique has the ability to measure three-dimensional flow field in a single view and single image,breaking through the limitation of the conventional focusing schlieren single section imaging,and has the ability to measure transient three-dimensional flow field.关键词
全息/聚焦纹影/三维测量/流场结构Key words
holography/focusing schlieren/three-dimensional measurement/the structure of flow field分类
数理科学引用本文复制引用
李奕勤,林志明,刘锴慧,薛志亮,金其文,吴迎春,吴学成..基于全息聚焦纹影技术的三维流场测量[J].实验流体力学,2025,39(4):9-18,10.基金项目
国家自然科学基金青年科学基金项目(52406209) （52406209）
浙江省自然科学基金资助项目(LZ24E06001) （LZ24E06001）
