Probabilistic description of grain resistance from simultaneous flow field and grain motion measurements
2008 (English)In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 44, no 9, W09419- p.Article in journal (Refereed) Published
Experiments were carried out using a mobile gravel bed placed in a tilting flume with a modified particle image velocimetry (PIV) system. Individual grain movements were surveyed using data from time series of images. Near-bed velocity flow field measurements were made simultaneously above the same area of the sediment surface by applying cross-correlation techniques to the collected plan view images. Statistics of grain motions were collected through a semiautomatic procedure. Significant changes in the flow field were observed in the proximity of the entrained or deposited particles. A strong correlation is shown between the changes in the local streamwise and lateral velocity and the movement of the grains. The theory of Grass is revisited and developed based on the experimental results. The probability distribution of individual grain resistance has been derived from the statistics of the near-bed velocity field and of the entrainment risk.
Place, publisher, year, edition, pages
American Geophysical Union (AGU), 2008. Vol. 44, no 9, W09419- p.
Ocean and River Engineering
IdentifiersURN: urn:nbn:se:kth:diva-80490DOI: 10.1029/2007WR006224ISI: 000259206200002OAI: oai:DiVA.org:kth-80490DiVA: diva2:496425
QC 201202152012-02-152012-02-092012-02-15Bibliographically approved