Verfahren zur zeitaufgelösten Aufnahme der dreidimensionalen Dichteverteilung in instationären Strömungen mit Hilfe von Multi-Video Hintergrund-Schlieren Aufnahmen

该研究项目的目的是重建时变，三维密度分布在非平稳流，测量折射率的变化，使用背景导向纹影（BOS）的方法的基础上。研究贡献包括改进的，每像素分辨率的BOS采集技术，一个简单的采集过程捕获多视频BOS数据的非平稳流，一个受约束的断层重建算法，需要比以前的方法少得多的输入数据，和基于渲染的验证方法，以获得物理上一致的结果。新技术和算法应与实验流体力学的合作伙伴合作进行实验评估。在供资期结束时，应提供一个软件系统，以获取任意非对称、非定常流随时间变化的体积密度分布。

This research project aims at reconstructing the time-varying, 3D density distributions in nonstationary flows, based on measuring the variations of the index of refraction using the background-oriented schlieren (BOS) approach. Research contributions include an improved, per-pixel resolution BOS acquisition technique, a simplied acquisition procedure for capturing multi-video BOS data of nonstationary flows, a constrained tomographic reconstruction algorithm that requires considerably less input data than previous approaches, and a rendering-based verification method to obtain physically consistent results. The novel techniques and algorithms shall be experimentally evaluated in cooperation with partners from experimental fluid mechanics. At the end of the funding period, a software system shall be available to acquire the time-dependent, volumetric density distribution of arbitrary non-symmetric, nonstationary flows.