A quantitative comparison of an over driven light emitting diode (LED) and a high intensity discharge lamp (HID) as illumination sources for high‐speed schlieren imaging is presented. A custom pulser circuit utilizing a new and improved driver circuit was developed to over‐drive the LED by a factor of ten while simultaneously reducing pulse widths to sub‐microsecond durations. The LED ...

This paper describes the development and use of background-oriented schlieren imaging a full-scale supersonic jet in flight. A series flight tests was performed April 2011, October 2014, February 2015, December 2018 using flora desert floor corridor near Edwards Air Force Base as background. Flight planning designed based on camera resolution, mean size color predominant plants, coordination se...

This article explains a simple way to demonstrate natural convection, such as from a lit candle, in the classroom using an overhead projector. The demonstration is based on the principle of schlieren imaging, commonly used to visualize variations in density for gas flows.

The complexity of brass instrument radiation theory has led to a large number of hypotheses and simplifications, which allow for the development of computable models. Most of these, used in the calculation of input impedances, sound simulation and instrument auralisation amongst others, are yet to be validated experimentally. Schlieren imaging techniques permit visualisation of pronounced gradi...

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren system is constructed from a Hoffman modulation contrast microscope, which provides easy access to the rear focal plane of the objective lens, by removing the slit plate and replacing the modulator with a knife-edge. The working principle of mi...

Two non-invasive optical Schlieren methods have been adapted to visualize brine channel development and convective processes in experimentally grown sea ice obtained when a NaCl aqueous solution is cooled from above in a quasi-two-dimensional Hele–Shaw cell. The two different visualization methods, i.e. traditional and synthetic Schlieren optical imaging, produce high spatial resolution images ...