Caleb Morrill-Winter

TL;DR: In this paper, a wide range of friction Reynolds numbers,, and equivalent sand grain roughness Reynolds numbers (smooth wall:, rough wall: ; ; and sandpaper roughness: ) are used to determine the mean wall shear stress using a floating element drag balance.

TL;DR: In this paper, a well-resolved measurement of the streamwise velocity in zero pressure gradient turbulent boundary layers is presented for friction Reynolds numbers up to 19,670, showing that the boundary layers undergo nearly a decade increase in Reynolds number solely owing to streamwise development.

TL;DR: In this paper, the spatial structure of smooth-and rough-wall boundary layers is examined spectrally at approximately matched friction Reynolds number, and the results show that over the resolved flow domain, which is limited to a streamwise length of twice the boundary layer thickness, true spatial spectra of smoothwall streamwise and wall-normal velocity fluctuations agree, to within experimental uncertainty, with those obtained from time series using Taylor's frozen turbulence hypothesis.

TL;DR: The inverse of the von Kármán constant κ is the leading coefficient in the equation describing the logarithmic mean velocity profile in wall bounded turbulent flows and it is demonstrated that the value of κ arises from two geometric features associated with the inertial turbulent motions responsible for momentum transport.

TL;DR: In this paper, multi-element hot-wire anemometry was used to measure spanwise vorticity fluctuations in turbulent boundary layers and a custom calibration/processing scheme was developed to utilize single-wall-parallel wires to optimize the accuracy of the measured wall-normal velocity fluctuations derived from the sensor's $$\times$$ -array.