Qualitative and quantitative visualization of unsteady flows – Movie by Ludwig Prandtl

Qualitative visualization - Movies

Around 1930 Ludwig Prandtl and his colleagues O. Tietjens and W. Müller of the Aerodynamische Versuchsanstalt Göttingen (AVA) published two films with visualizations of flows around surface piercing obstacles to illustrate the unsteady process of flow separation.

The contents of these movies is described in

  • Entstehung von Wirbeln bei Wasserströmungen, Veröffentlichungen der Reichsstelle für den Unterrichtsfilm zu den Hochschulfilmen C1 und C2, 3 Seiten, Berlin 1932

A reprint of this description can be found on pages 817-818 of

  • Tollmien W., Schlichting H., Görtler H., Riegels F.W. (1961) Entstehung von Wirbeln bei Wasserströmungen. In: Riegels F.W. (eds), Ludwig Prandtl Gesammelte Abhandlungen. Springer, Berlin, Heidelberg,

The movies have been digitized by the Institut für Wissenschaftlichen Film, Göttingen in 2009 and are now available at the Technische Informationsbibliothek Hannover.



  • Entstehung von Wirbeln bei Wasserströmungen -
    2. Anwendungen auf die Strömung durch Krümmer, Hohlräume und Verzweigungsstücke,
Snap shot of flow field with tracer particles behind a wedge

Sample of movie: Flow behind wedge

Quantitative visualization - Movies

Because these visualizations were achieved by recording the motion of fine particles sprinkled onto the water surface in water channels the resulting images meet the relevant criteria of properly seeded recordings for particle image velocimetry (PIV). Processing these image data with modern PIV algorithms allows the visualization of flow quantities (e.g. vorticity) that were unavailable prior to the development of the PIV technique.

 The PIV analysis of the original film sequences, which has been contributed to the "Gallery of Fluid Motion", 63rd Annual APS-DFD Meeting 2010, Long Beach (CA) is described in

Snap shot of velocity field with vorticity behind a wedge

Sample of movie: Flow behind wedge

The accompanying fluid dynamics video consists of selected original film sequences overlaid with visualizations obtained through PIV processing. It is available for download at TIB Hannover

  • C. Willert, J. Kompenhans. Particle Image Velocimetry (PIV) analysis of Ludwig Prandtl‘s historic flow visualisation films,

It is obvious that movies provide better insight in unsteady flow phenomena than still photographs. However, in most cases (analog) movies can only display qualitative information.

By digitizing 80 years old, high quality analog movies and making use of modern computers and evaluation algorithms, quantitative information can be extracted from them as well.

Nowadays the exchange of images and movies of flow visualization results in digitized format is possible world-wide within seconds. New experimental methods, based on quantitative flow visualization have been developed and allow in close international scientific cooperation to gain new and deeper insight in complex unsteady flow phenomena.


Contents provided by Chris Willert and Juergen Kompenhans, 20171012