Quantitative flow visualization

Modern developments in laser and computer technology, electronic cameras, a nd digital image processing techniques allow to generate planar distributio ns of quantitative data in turbulent flows. Large amounts of data can be pr ocessed easily and analyzed statistically. With these tools, it is possible to quantitatively visualize turbulent coherent structures, even in flows o f high Reynolds number, and measure characteristic spatial quantities like vorticity, length scales, spatial correlation functions, etc. These potenti als in analyzing spatial characteristics of turbulent flows are demonstrate d with two different methods of quantitative flow visualization: speckle ph otography as a representative of the line-of-sight methods, and particle im age velocimetry belonging to the methods that rely on the scattering of las er Light from tracer particles.