This paper presents the experimental results on similarity velocity profile of vortices inside the cavities, formed between two neighboring girders, under a partially inundated bridge deck. Particle image velocimetry (PIV) and flow visualization technique are both employed to explore the flow field. The approaching flow is subcritical with Froude number varying in the range 0.137–0.381. The velocity characteristics of vortex structure inside the cavities under a partially inundated bridge deck, where water is fully occupied without air-pocket, are mainly investigated. The similarity profile of the azimuthal velocity along an arbitrary line, passing through the vortex core, is uniquely obtained using the measured azimuthal velocities for two different flow types. The selection of the characteristic length and velocity scales used for obtaining the similarity profile is discussed in this study.
QC 20160107