| We are using Planar Laser-Induced Fluorescence (PLIF) to visualize flows and quantitatively measure temperature in shock tube flow fields. This highly sensitive and accurate method uses toluene as a fluorescence tracer. The technique has been used to study complex supersonic flows, specifically the interaction of a moving shock with a wedge. Measured temperatures agreed well with results of numerical simulations in all inviscid regions, and all pertinent features of the single Mach reflection are resolved. |
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| Incident shock over wedge |
Figure 1. Left: PLIF signal image of an incident shock traveling over a wedge. The single Mach reflection is visible as well as the diffraction effect in the incident shock wave transition when a laser is introduced through the side window. Right: Schematic of a single Mach reflection, adapted from G. Ben-Dor (2007). |
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| Shock wave/boundary layer interaction imaging |
| The following composite image is a time series of images generated using PLIF (Planar Laser-Induced Fluorescence) technique. Fluorescence in these images is a result of the interaction of an intense excimer laser pulse and a tracer (toluene). The images show the interaction of a moving shock reflected from the end wall of our imaging shock tube with the turbulent boundary layer trailing the incident shock. The reflected shock moves from right to left and the incoming flow is moving from left to right. The time series shown below is a collection of single-shot, independent realization under nominally the same conditions. |
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| The following composite image shows a comparison of an experimental observation and simulation using the LES code Charles of a reflected shock wave interacting with a turbulent boundary layer in the Stanford imaging shock tube. The gas mixture is such that the reflected shock wave bifurcates as it moves to the left and the interaction of this shock bifurcation and the boundary layer produces a series of disturbances that trail this structure. Two single-shot images at different time delays are shown. |
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