کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4541180 1326711 2009 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Estimation of the wave-related ripple characteristics and induced bed shear stress
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Estimation of the wave-related ripple characteristics and induced bed shear stress
چکیده انگلیسی

A large data set on ripples was collected and examined. A set of new formulas for the prediction of the ripple characteristics is proposed with an emphasis on the disappearance of the ripples. The ripple wavelength was observed to be proportional to the bottom wave excursion but also to be a function of the grain-related Shields parameter and wave period parameter introduced by Mogridge et al. (1994). The ripple steepness was found to be nearly constant for orbital ripples, and with a sharp decrease for suborbital ripples. Two empirical functions are added including the effects of the critical Shields parameters (inception of transport and inception of sheet flow), i.e. giving the boundaries for the ripple existence's domain. The proposed formulas yield better prediction capabilities compared to the previously published formulas, especially when ripples are washed out. The effect of the ripple characteristics on the roughness height and the calculation of the bed shear stress is also discussed. It appeared that the bed shear stress calculation is more sensitive to the empirical coefficient ar introduced in the estimation of the ripple-induced roughness height or to the limits of existence of the ripples than the ripple characteristics themselves.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Estuarine, Coastal and Shelf Science - Volume 84, Issue 4, 10 October 2009, Pages 553–564
نویسندگان
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