An Experimental Study on Surface Wave Modulation Due to Viscoelastic Bottom
In the present study, we developed viscoelastic bottom layers of required rheological properties in the laboratory using a mixture of a polymer, polydimethylsiloxane with glycerol. The properties of the viscoelastic layers were quantified using oscillatory shear tests in a rheometer. Wave flume experiments with different viscoelastic bottom layers were then conducted under shallow water conditions. The synchronized time series data at seven locations along the direction of wave propagation were obtained using ultrasound sensors, which were used to determine the attenuation rate due to the presence of the bottom boundary. The results of the analysis showed that the attenuation rate of waves change with the variation of rheological property of bottom boundary, with the softer bottom attenuating the waves more significantly.
KeywordsViscoelastic bottom Attenuation Shallow water
This work is supported by US Office of Naval Research Grant #N00014-13-1-0294 and US Office of Naval Research Global Grant No: N62909-15-1-2069. The authors would like to thank Mr. Peh Zhisheng at the Nanyang Technological University for assisting in the experiments.
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