An analysis of wave dissipation at the Hendijan mud coast, the Persian Gulf

Abstract

Effects of non-rigid muddy bed on the wave climate at the Hendijan coast along the northwestern part of the Persian Gulf have been examined through field measurements and numerical wave transformation modeling. The field survey included measurements of wave characteristics at an offshore and a nearshore station, and mud sampling to obtain the thickness of the fluid mud layer and its rheological properties. Comparisons of wave spectra at the two stations show energy dissipation along the wave trajectory with higher dissipation in the wave period band around 6 s, because depending on the site a given frequency band tends to be more effective in wave-mud interaction. Dissipation induced by the non-rigid bed is introduced into the REF/DIF wave transformation model through the application of viscoelastic constitutive equations for fluid mud. Numerical outputs of the nearshore wave height, for which the viscoelastic parameters included in the model were obtained independently from oscillatory frequencysweep tests, are found to be comparable with measured values at the nearshore station. This implies that the model is useful for estimating the design wave conditions in the study area.

Acoustic wave propagation in gassy porous marine sediments: The rheological and the elastic effects

“…First, the damping expression (34) assumes a 1/ dependence between the elastic and viscous responses of the sediment, and combines both dissipation mechanisms into one single term. In contrast, experimental studies [39,[45][46][47][48][49] that have reported both the shear and the viscous properties (flow curves) of sediments do not suggest a straightforward 1/ dependence between the two. The elastic and the viscous responses may vary individually, depending on the strain amplitude and/or frequency ranges (in for example, shear viscosity [58,59] and elastic modulus [61]).…”

“…The elastic and the viscous responses may vary individually, depending on the strain amplitude and/or frequency ranges (in for example, shear viscosity [58,59] and elastic modulus [61]). These may furthermore depend on the salinity, the mineralogical composition and the concentration [46,48]. Second, there exists a discrepancy because of the use of Re( * ) in the resonance frequency expression (35) and Im( * ) in the damping coefficient (34).…”

“…Furthermore, the current paper proposes the use of sediment viscosity values obtained from rheological experiments [45][46][47][48][49].…”

A Study on the Sand-Mud Mixture at North-West of the Persian Gulf

“…The north-western part of the Persian Gulf is covered with mud, originated mainly from the catchment area of Arvand River (Haghshenas and Soltanpour, 2010). Mud deposits up to 20 meters thickness is observed at the very shallow coast of Hendijan Fishery Port, located at the north-western shoreline of the Deylam Bay; while very fine sand with oolitic origin is dominant at Deylam Port in the south-eastern corner of the bay.…”

“…A set of field measurements was performed at the field site from 20th of February to 28th of March, 2007 (Haghshenas andSoltanpour, 2010). Directional wave spectra and vertical current profiles were simultaneously recorded at two nearshore (2.5 m deep) and offshore (10 m deep) stations.…”