Author(s): Zhenhua Huang; Lei Ding
Linked Author(s):
Keywords: Bottom wave-current boundary layer; Regular waves; Hydraulic resistance; Wave attenuation; Time-mean drift current
Abstract: In coastal water sediment grains may be the carriers of nutrients and contaminants. The transport of sediment grains on beaches or in estuaries is strongly influenced by the near-bed mean drift induced by waves and current in the onshore/offshore direction. Thus the study of wave-current interaction finds its application in the shore protection and water quality control. In this paper, velocity measurements were conducted at various locations between the roughness elements to study the effects of waves on an opposing turbulent current over a fixed artificial rough bed. It was found that trend on the wave-induced change of the near bottom time-mean velocity was not affected by the ratio of the wave amplitude to the spacing between roughness elements (a/λ), which was found important for the time-mean drift in pure waves (Ridler and Sleath (2000) ). The wave-current boundary layer theory of Grant and Madsen (1986) was evaluated for laboratory conditions based on the spatially averaged velocity. The present velocity measurements and those of Kemp and Simons (1983) have provided a complementary set of data for the testing of bottom wave boundary layer models for wave-opposing current.
Year: 2005