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The Structure of the Drag Reduced Turbulent Flow over a Backward Facing Step — an experimental study

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Part of the Notes on Numerical Fluid Mechanics (NNFM) book series (NONUFM, volume 40)

Summary

Aqueous solutions of polyacrylamide (Separan AP45, 50 ppm) or some cationic surfactant additives (mixtures of tetradecyl-trimethyleammoniumbromide with sodium salicylate) exhibit the effect of drag reduction in turbulent pipe flows. From previous investigations it could be concluded that this effect is based on the change of the structure of turbulent motion. The aim of this work is the experimental investigation on the influence of drag reducing additives on the features of turbulence.

The description of turbulent structures leads to a better understanding of the effect of drag reduction and offers deeper insights to turbulence in general. The chosen geometry of a backward facing step supplements investigations of other turbulent flows, e.g. the plane mixing layer (Kwade 1982) or pipe flow (Bewersdorff et al. 1986).

Keywords

Shear Strain Reynolds Stress Coherent Structure Surfactant Solution Separation Point 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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Copyright information

© Springer Fachmedien Wiesbaden 1993

Authors and Affiliations

  1. 1.Fachbereich ChemietechnikUniversität DortmundDortmund 50Germany

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