Transverse Modal Vibrations of Vertical Tensioned Risers. A simplified Analytical Approach — The paper examines the physics of riser transverse modal vibrations of the type induced by VIV (Vortex Induced Vibrations). It presents a simplified analytical solution for such vibrations of vertical tensioned risers with uniform linear characteristics. The solution leads to simple expressions for the ...

We create a ’virtual-seabed’ platform to realize the 3D visual analysis of seabed on smartphone. The 3D seabed platform is based on a ’section-drilling’ model, implementing visualization and analysis of the integrated data of seabed on the 3D browser on smartphone. Some 3D visual analysis functions are developed. This work presents a thorough and interesting way of presenting seabed data on sma...

Uncertainty in seabed properties can lead to substantial uncertainties in acoustic propagation, of order tens of dBs. During this project, substantial progress was made in 1) quantifying seabed uncertainties, by developing an advanced seabed measurement technique and powerful commensurate methods to estimate the uncertainties and 2) predicting the effect of those effects on propagation by devel...

Deepwater subsea wellheads may be significantly threatened under extreme sea conditions and operations, especially when the seabed is composed of very soft clay properties. A numerical model a deepwater wellhead system established using classic ocean pipe element nonlinear spring ANSYS to examine behaviors in diverse soil. Nonlinear elements coded APDL language are used three types soils: soil,...

This work concerns modeling of very high frequency (>100 kHz) sonar images obtained from a sandy seabed. The seabed is divided into a discrete number of ID height profiles. For each height profile the backscattered pressure is computed by an integral equation method for interface scattering between two homogeneous media as formulated by Chan [IEEE Trans. Antennas Propag. 46, 142-149 (1998)]. Ho...

Seabed classification is the important part of current coastal research because it characterizes the seabed and its habitats. Seabed characterization makes the link between the classified area and the physical, geological, chemical or biological properties of seabed. This paper addresses the possibilities of the use of airborne hyperspectral sensing with a CASI-1500 sensor to map the seabed cov...

−The information of particle cluster dynamics is necessary for improving the performance of a circulating fluidized bed system. The main objective of this study is to compare the particle cluster diameters and concentrations from computational fluid dynamics simulation results between circulating fluidized bed riser and downer. The calculation methodologies are based on the concept of kinetic t...