Hartmann Sensor and Dynamic Tomographical Analysis of Organized Structure in FlowFields

摘要

In the Aero-optics research program currently underway at the PhillipsLaboratory, we are examining the relationship between the organized structure in the near field region of an axisymmetric jet and the degradation of an optical field that propagates through the jet shear layer. We are developing an experimental capability in which dynamic tomographical analysis enables us to reconstruct a time series of flow field images while simultaneously recording the optical phase incurred along many paths through the flow. From such simultaneous information we can infer relevant flow structures. In this paper we present an analysis of the one dimensional Hartmann sensing technique with which we intend to make time resolved tomographic measurements. We discuss the sensitivity and noise characteristics of the sensor and present novel, high resolution, measurements of flow field structure that have been obtained from Hartmann sensor measurements. Additionally, computed tomographic reconstructions of flow field cross sections are created using information from the Hartmann sensor measurements. We employ these simulations to analyze the expected quality of time-resolved tomographic reconstructions and to create an optimized design of an experimental dynamic tomographic system based on Hartmann sensing.