Oxford Lasers imaging systems are designed to visualise heat transfer events, perform 2D / 3D velocity analysis or measure particle / droplet size and velocity data. Uniquely, it is possible to perform all three tasks with the same system.
High speed imaging has long been used to understand the fast evolution of events taking place during a wide range of complex industrial, chemical and engineering processes.
VisiLase systems use pulsed lasers to freeze the motion of the subject, with high speed cameras to capture images at up to 50,000 frames per second. The high light intensity provided by the laser enables visualisation of very small fields of view with very high resolution. This means that complex events such as bubble growth and spray break up can be examined in detail.
Particle Image Velocimetry (PIV) is an established technique for capturing 2D & 3D velocity data at one instant in time from a fast moving flow. The Oxford Lasers VisiVector range offers this facility, but also has the capability of making time resolved measurements in turbulent flows.
A laser light-sheet is used to slice through the flow under analysis. The camera stores pairs of images as they are illuminated by separate pulses from the laser.
Measurements can be taken with a resolution of up to 100,000 times per second. This capability allows the analysis of transient events such as vortices in highly turbulent flows, typically found in bubbly water flows of heat exchangers or car engine air-flows. However fleeting, the whole event can be captured and analysed from start to finish.
The Oxford Lasers VisiSizer systems, have been developed for the measurement of particles, droplets and bubbles in sprays and water flows. As the systems are based on high speed imaging, it is not only possible to measure the droplet / bubble size and velocity simultaneously, but a sequence of frames shows the way they change in shape and size
VisiSizer measures droplets / bubbles down to 1 micron in size (with no upper limit), deals with non-spherical shapes, measures velocity vs. size and analyses up to 7500 droplets per second in real time. The system is also capable of sizing out-of-focus droplet images by measuring the sharpness of the image edges and determining the correct size