Transonic Flow Separation in Closed Curved Channels.

摘要

The predominantly phenomenological study has been oriented towards basic physical understanding of the development and structure of transonic flow in closed curved channels, namely of the strong interaction of the terminal shock wave with various vortical structures. A new classification of vortical structures according to the forces generating them has been suggested. Flow separation in this typically three-dimensional case has been analyzed and several simple separation criteria have been suggested. They can be used in the analysis of experimental results as well as in numerical studies. However, it has become obvious that the local separation criteria are not sufficient and that rather some global criteria have to be looked for. Experiments carried out so far were based on the flow and surface streamline visualization. They provide material for the basic qualitative analysis of the flow phenomena but are only of a limited value for quantitative measurements. For this purpose a double pulse laser has been commissioned with the intention to apply the particle image velocimetry.