Stanford
Hanson Research Group

Schlieren Imaging

an example of Schlieren imaging showing the typical grey background and some small object represented in black

Schlieren imaging is an essential diagnostic in gas dynamics offering valuable insights into flow structures otherwise impossible to visualize.

Sensitive to density gradients in the flow field, schlieren imaging reveals qualitative and quantitative flow features. Using a high-speed camera, capable of recording at 1 million frames-per-second, and in-house designed precision optics, we apply high-speed, high-resolution schlieren imaging to shock tube flows, aiding the design of next-generation energy and propulsion systems.

With the current schlieren system, propane flame speeds can be measured at extreme, engine-relevant temperatures, up to 1200 K, for the first time [1]. We are also exploring opportunities to use schlieren-based flow visualization to advance the understanding of high-speed reactive gas dynamics.

diagram of a Schlieren system
Schematics of schlieren system

To learn more, check out some of our publications:

[1] A. J. Susa, L. Zheng, and R. K. Hanson, “Schlieren-based measurements of propane flame speeds at extreme temperatures,” in 12th US National Combustion Meeting (2021)