An Omnidirectional Wall Shear Meter

Abstract

An omnidirectional wall shear meter has been developed which is capable of the direct measurement of both magnitude and direction of wall shear stress. Linearity, resolution, and accuracy have been demonstrated analytically and experimentally by static and dynamic calibration. The floating element device works on the cantilevered beam principle. Eddy current probes, set at right angles to the beam and to each other, sense the magnitude and direction of deflection which can be calibrated against known force loadings. The device is used to measure wall shear stress in three-dimensional flows, and was specifically developed as a means of validating proposed three-dimensional near-wall similarity laws.