Locally resolved flow diagnostics by means of lightfield measurements

• Applicant: Dr.-Ing. Stefan Löhle
• Subject Area: Fluid Mechanics
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 325614075

The understanding of high-enthalpy flowfields such as in combustion processes, plasma technology and hypersonic flight lacks the measurement of the instantaneous, three-dimensional distribution of temperatures and species. In general, non-intrusive optical diagnostic methods are a versatile tool for the analysis, but may require extensive optical access, which is very often limited in the problems of interest. Other optical diagnostics reach a high level of resolution, but are limited to two dimensions.This project aims at using lightfield analysis for the characterisation of high-enthalpy flows. In principle, this technology allows to determine spatial distributions from one single photographic exposure. Lightfield imaging has recently become commercially available. However, it has not yet been used for analysing flowfields, particularly not hot, chemically reactive and brightly luminous flows as for example in ground testing facilities for hypersonic flight.In a first step the algorithms required for the analysis of three-dimensional scalar fields shall be developed and implemented. The methods are then validated with the aid of lightfield images taken with a commercial camera system and appropriate phantoms. This forms the basis for using lightfield images of the high-enthalpy flow to determine the instantaneous, spatial (3D) distribution of the chemically reacting species. Such an acquisition is unique and of crucial importance for the assessment of high speed reacting flows.

• DFG Programme: Research Grants
• Major Instrumentation: Lichtfeldkamerasystem
• Instrumentation Group: 5450 Photographische Spezialkameras (Luftbild-, Registrier-, Stereo-, außer