کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1721450 1014492 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Lagrangian measurements and modelling of fluid advection in the inner surf and swash zones
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی دریا (اقیانوس)
پیش نمایش صفحه اول مقاله
Lagrangian measurements and modelling of fluid advection in the inner surf and swash zones
چکیده انگلیسی

New laboratory and field data are presented on fluid advection into the swash zone. The data illustrate the region of the inner surf zone from which sediment can be directly advected into the swash zone during a single uprush, which is termed the advection length. Experiments were conducted by particle tracking in a Lagrangian reference frame, and were performed for monochromatic breaking waves, solitary bores, non-breaking solitary waves and field conditions. The advection length is normalised by the run-up length to give an advection ratio, A, and different advection ratios are identified on the basis of the experimental data. The data show that fluid enters the swash zone from a region of the inner surf zone that can extend a distance seaward of the bore collapse location that is approximately equal to half of the run-up length. This region is about eight times wider than the region predicted by the classical swash solution of Shen and Meyer [Shen, M.C., Meyer, R.E., 1963. Climb of a bore on a beach. Part 3. Runup. Journal of Fluid Mechanics 16, 113–125], as illustrated by Pritchard and Hogg [Pritchard, D., Hogg, A.J., 2005. On the transport of suspended sediment by a swash event on a plane beach. Coastal Engineering 52, 1–23]. Measured advection ratios for periodic waves show no significant trend with Iribarren number, consistent with self-similarity in typical swash flows. The data are compared to recent characteristic solutions of the non-linear shallow water wave (NLSW) equations and both finite difference and finite volume solutions of the NLSW equations.The model results are transformed into a Lagrangian reference frame to illustrate particle trajectories, from which advection lengths and particle excursions into and across the swash zone are determined. The particle excursions represent a horizontal mixing length for fluid and sediment and define length scales over which boundary layer growth occurs during run-up. The model results are in excellent overall agreement with the means of the data series. The region defined by the advection length represents the potential effective pickup zone for pre-suspended sediment, and therefore represents an important but diffuse boundary for sediment transport modelling in the inner surf and swash zone.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Coastal Engineering - Volume 55, Issue 10, October 2008, Pages 791–799
نویسندگان
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