A new way to determine the wall position and friction velocity in wall-bounded turbulent flows

Authors: Alfredsson, P.H., Örlü, R.
Document Type: Conference
Pubstate: Published
Journal: Progress in Turbulence and Wind Energy IV, Springer Proceedings in Physics, Proceedings of the iTi Conference in Turbulence 2010
Volume: 141   181-185
Year: 2012


In experiments using hot-wires near the wall it is well known that heat conduction between the hot-wire and the wall gives errors and mean velocity data from the viscous sublayer can usually not be used to determine the wall position, nor the friction velocity from the linear velocity distribution. Here we introduce a new method which takes advantage of the similarity of the probability density distributions, or rather the cumulative distribution function (CDF) in the near wall region. By using the velocity data in the CDF in a novel way, it is possible to circumvent the problem associated with heat conduction and to accurately determine both the wall position and friction velocity.