Abstract

ABSTRACTMulti-plane stereoscopic PIV measurements were performed in an open-channel flume fitted with cubes to investigate very low submergence ratios, , where h is the water depth and k the roughness height. The spatial standard deviation of the mean flow components reveals that the extent of the roughness sublayer increases drastically with the decrease in h/k to span the entire water column for the lowest h/k investigated. Despite this, the logarithmic law is still observed on the double-averaged velocity profiles for all h/k, first with a fixed von Kármán constant κ and, second, via the indicator function where κ is a free parameter. Also, the longitudinal and vertical normal stresses indicate a universal boundary layer behaviour independent of h/k. The results suggest that the logarithmic and wake-defect laws can still be applied at such low h/k. However, the lateral normal stress depends on h/k in the range investigated as well as on the geometry of the roughness pattern.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.