Refinement of pattern recognition of coherent structures in turbulent shear flows and a comparison between detection techniques
The present account summarizes changes recently incorporated into the pattern recognition (PR) program used by Wallace, Brodkey, and Eckelmann (1977). These changes were instituted so that detailed comparisons could be made between the PR technique and other detection schemes for coherent structures currently in vogue [e.g., VITA and quadrant splitting (QS)]. The X-film data obtained in the Göttingen oil channel were analyzed by the new program to extract additional information to provide a detailed comparison between techniques. The comparison is presented as a composite picture of the key elements of the sequence of events.
KeywordsPattern Recognition Coherent Structure Positive Slope Amplitude Criterion Turbulent Shear Flow
Unable to display preview. Download preview PDF.
- Blackwelder, R.F. & Kaplan, R.E. 1976 J. Fluid Mech. 76, 89.Google Scholar
- Brodkey, R.S. 1978 Proc. Workshop on Coherent Structure of Turbulent Boundary Layers, Bethlehem, Pa. (May 1–3).Google Scholar
- Brodkey, R.S., Wallace, J.M. & Eckelmann, H. 1974 J.Fluid Mech. 63, 209.Google Scholar
- Corino, E.R. & Brodkey, R.S. 1969 J.Fluid Mech. 37, 1Google Scholar
- Eckelmann, H., Nychas, S.G., Brodkey, R.S. & Wallace, J.M. 1977 Phys. Fluids 20, 5225.Google Scholar
- Praturi, A.K. & Brodkey, R.S. 1978 J. Fluid Mech. 89, 251.Google Scholar
- Wallace, J.M., Eckelmann, H. & Brodkey, R.S. 1972 J. Fluid Mech. 54, 39.Google Scholar
- Wallace, J.M., Brodkey, R.S. & Eckelmann, H. 1977 J. Fluid Mech. 83, 673.Google Scholar