Density Measurements of a Turbulent Wake Using Acetone Planar Laser-Induced Fluorescence

作者：Reid John Z^*; Lynch Kyle P; Thurow Brian S

来源：AIAA Journal, 2013, 51(4): 829-839.

DOI：10.2514/1.J051678

The application of a planar density measurement technique for compressible flowfields based on acetone planar laser-induced fluorescence is presented. An error analysis indicates a minimum inherent uncertainty of similar to 2.5% in density measurements due to uncertainty in local pressure and a total experimental uncertainty of 8%, primarily driven by shot noise due to low-signal levels. The technique is demonstrated through the visualization of the separated shear layer and turbulent wake of a wall-mounted hemisphere at a freestream Mach number of 0.78 and a Reynolds number of approximately 900,000. The flow is marked by a large-scale flapping motion of the wake and low-density vortex cores, where density drops of up to 50% of the freestream density are detected. In addition, closeup images of the shear layer near the separation point reveal the formation of lambda shocks. The density fields are used to perform aerooptic distortion calculations through spatial integration of the density field. A correlation is found between the spatial scale of the distortion and the features present in the density field. These findings demonstrate the viability of acetone planar laser-induced fluorescence for conducting planar density measurements and providing a new method for the evaluation of aerooptic distortion in compressible flows.

• 出版日期2013-4