Schlieren image velocimetry (SIV) is based on light deflection through flow heterogeneities and cross-correlations. This a low-cost relatively low complexity technique that allows measurement of the droplet velocity field in large region spray. A Z-type Toepler schlieren system with high-speed camera was used to determine mean vertical horizontal velocities, as well cone angles sprays produced ...

The ‘‘synthetic schlieren’’ method has been used to measure the amplitude of internal waves that are two-dimensional and axisymmetric. Here it is adapted to reconstruct fully three-dimensional perturbations. This non-intrusive technique, which uses inverse tomography methods, shows accurate results when a sufficient number of perspectives taken from the same experiment are provided to the inver...

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 ...

The burning behaviour of a wooden rod under various forced flow conditions was investigated by employing synchronised multi-imaging system integrating visible wavelength, short-wavelength infrared (SWIR), and Schlieren techniques. wood samples were fixed horizontally at an inclined angle to study the effect surface orientation flow. A small-scale wind tunnel developed supply three types flow: c...

To produce geometrically complex parts with good mechanical properties, various industries increasingly apply the powder bed fusion of metals using a laser beam. Sufficient control this laser-based additive manufacturing process is necessary to achieve reliable development as well reproducible part properties. Besides adjusting standard parameters, such power or scanning speed, gas an important...

Background/introduction FUS pressure field mapping is important for dosimetry, quality assurance, and other uses. Hydrophone measurements are the current standard, and are accurate but costly and slow. As a simple low-cost alternative, background-oriented schlieren (BOS) imaging of ultrasound fields has been proposed.[1] In that technique, a predetermined image (usually a grid of lines or a ran...

Laser powder bed fusion (LPBF) is of great importance for the visual measurement and analysis metallization process, which process solid, liquid, gas phase transformations metal powders under high-energy laser irradiation due to low boiling point/high saturated vapor pressure. Since evaporation metals involves interaction driving forces such as back pressure, surface tension, gravity, movement ...