Light Sheet Visualisation
Here a laser light beam is expanded in one direction only with the help of a cylindrical lens. This so called light sheet is then used to illuminate a flow seeded with tracer particles (smoke or tiny oil droplets in air, bubbles in water). In such a light sheet the light intensity detected in the plane of an observing camera will depend on the flow geometry and the concentration of the particles in the light sheet (if only one particle size is used for visualisation). This technique provides a fast mean for real time flow visualisation. At the Institute for Thermal Turbomachinery and Machine Dynamics a high-speed video camera (Kodak Ektapro 1000)
might also be used for flow visualisation. Depending on the laser power even larger areas can be illuminated and the flow visualised.
MPEG video (264 KB)
This video demonstrates the effects of light sheet visualisation by observing a
free air jet. This air jet was generated by a smoking man.