Animated visualization of shock-wave flow fields for dynamic comparison between experiment and computational prediction

摘要

Abstract: Through the use of digital image processing and advanced shock tube technology, a more stringent comparison of experimental data with computational predictions can be achieved. Holographic interferometry is used to visualize density distributions of shock wave flows experimentally. Experiment-like images are created from numerical data using the optical parameters of the experiment. In the case of axisymmetric flow a ray-tracing algorithm is incorporated to produce the correct images. Where many dynamic processes, such as multiple shock reflections, occur the use of a single image is not sufficient. For these cases a specially designed shock tube is used in combination with a computer controlled trigger to yield images obtained at constant experimental conditions but different moments in the development of the flow. This data is combined into animation sequences. This presentation of results provides a better insight into the flow physics and CFD code behavior. The combination of a physical interpretation of numerical data and a dynamic comparison of images has been found to greatly enhance the quality of CFD code validation with the experiment. !5