Interpretation of Schlieren Density Gradient Photographs

Whole-field density measurements by `synthetic schlieren'

This paper outlines novel techniques for producing qualitative visualisations of density ̄uctuations and for obtaining quantitative whole-®eld density measurements in two-dimensional density-strati®ed ̄ows. These techniques, which utilise image processing technology, are much simpler to set up than the classical schlieren and interferometry methods, and provide useful information in situations ...

Schlieren Measurements of a High Density Z-Pinch

The dense plasma phase of a dynamic z-pinch working at a high filling pressure is studied. By using the Schlieren-technique it is found that the compressed plasma column, though macroscopically stable for times less than 1 /us develops quickly from a homogeneous state to a turbulent one with a perturbation scale length of typically some millimeters. Quantitative measurements of light deflection...

Density measurements using the Background Oriented Schlieren technique

This paper describes the implementation of a novel technique called Background Oriented Schlieren that can produce quantitative visualization of density in a flow. This technique uses only a digital still camera, a structured background, and inverse tomographic algorithms which can extract two-dimensional slices from a three-dimensional flow. This has been applied to obtain the density field fo...

Assessment and application of quantitative schlieren methods: Calibrated color schlieren and background oriented schlieren

Two quantitative schlieren methods are assessed and compared: calibrated color schlieren (CCS) and background oriented schlieren (BOS). Both methods are capable of measuring the light deflection angle in two spatial directions, and hence the projected density gradient vector field. Spatial integration using the conjugate gradient method returns the projected density field. To assess the perform...

Preparative Density Gradient Centrifugations