Did you know TracePro can model Schlieren imaging systems? Schlieren imaging is an imaging method by which changes in the index of refraction of a transparent medium such as air or another gas can be shown. Some examples of Schlieren imaging are fluid dynamics, visualizing heat waves from a flame or other heat source in the air, or the turbulence behind a fast-moving projectile.
One example of a Schlieren imaging system is the Two Lens Schlieren system. In this method a small light source is typically used. Ideally a point source would be used, but that is not physically possible. The first lens in the system collimates the light into a beam. The second lens then refocuses the light. A knife edge or slit is placed at the focal point of the second lens. The rays that pass the knife edge are then collected by an imaging sensor such as a CCD detector or film. Other types of Schlieren imaging systems are also possible.
Lenses for a two lens Schlieren system in TracePro can be made in TracePro using the Lens Element dialog box, using catalog lenses from major lens manufacturers, or imported from a lens design program such as OSLO.
The test subject is placed in the beam between the two lenses. In the example shown here, a 3D model of a helical path is placed between the lenses. This object has a slightly different index of refraction compared to the surrounding medium, air in this model.
The results on the detector can then be viewed using the Irradiance/Illuminance Map in TracePro.
Schlieren imaging systems can be quickly and easily modeled in TracePro, allowing for analysis of the results and the effects of any changes made to the system or the test subject.