Universality of probability density distributions in the overlap region in high Reynolds number turbulent boundary layers
2004 (English)In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 16, no 7, 2587-2591 p.Article in journal (Refereed) Published
The probability density functions (PDFs) of the streamwise mean velocity in high Reynolds number turbulent boundary layers have been studied. The hypothesis of self-similar, normalized with the root mean square velocity, PDFs has been tested using the KTH database of high Reynolds number zero pressure-gradient turbulent boundary layer flow. The self-similarity was tested using the Kullback-Leibler divergence measure and it was found that the region of self-similar PDFs extends from about 160 viscous wall units to about 0.3 boundary layer thicknesses (in delta(95)). This region is somewhat larger than the universal overlap region. The PDF shape in the universal overlap region is close to Gaussian allowing for a Gram-Charlier expansion approximation of the measured PDFs. A remarkable collapse was found for 57 normalized PDF distributions for different positions within the universal overlap region and Reynolds numbers based on the momentum-loss thickness between 4300 and 12 600, strongly indicating a high degree of flow universality within the universal overlap region. Within the range studied, the Gram-Charlier expansion coefficients (related to the PDF moments) show no Reynolds number trend further supporting the self-similarity hypothesis.
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2004. Vol. 16, no 7, 2587-2591 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-78978DOI: 10.1063/1.1738416ISI: 000221951400045OAI: oai:DiVA.org:kth-78978DiVA: diva2:493888
QC 201203052012-02-082012-02-082012-03-05Bibliographically approved