A new type of projection schlieren camera system (schlierenscope) is more portable, easier to align, and more versatile than existing systems. The schlierenscope is a projection focusing schlieren camera system that can acquire images of shock waves, vortices, gas jets, and other disturbances that create gradients in the refractive index of a transparent medium. These gradients appear as streaks (called schlieren in German) in the resulting image. Thus, a schlierenscope is an apparatus for looking at disturbances in transparent media. The schlierenscope constructed in the project utilizes fast strobes that freeze motion and capture images with a scientific CCD (charge-coupled device) camera. The schlierenscope is unique among schlieren instruments because all of the critical controls are contained within the instrument housing.
Compared to conventional schlieren systems, the schlierenscope is compact and easier to use, which makes it possible to photograph airflows in industrial settings where traditional laboratory instruments are too delicate and complex. To improve ventilation systems and blowers, the engineers who design them require portable camera systems that allow them to visualize airflow. When the schlierenscope is equipped with strobes and high-speed cameras, it can visualize shock waves from explosions, which makes it applicable for many safety applications.
This work was done by Drew L’Esperance of MetroLaser, Inc. and Leonard Weinstein of the National Institute of Aerospace Associates (NIAA) for Glenn Research Center.
Inquiries concerning rights for the commercial use of this invention should be addressed to
NASA Glenn Research Center
Innovative Partnerships Office
Attn: Steven Fedor
Mail Stop 4–8
21000 Brookpark Road
Cleveland
Ohio 44135.
Refer to LEW-19095-1.