This study investigated vortex-induced vibrations of marine risers in Ocean Thermal Energy Conversion systems. Flume experiments were conducted under two conditions: Condition 1 was with a fixed riser bottom, and 2 bottom on mooring platform. The cross-flow acceleration the measured at different current velocities, corresponding vibration responses analyzed. Numerical simulations based flume em...

To understand the influence of collector design parameters on the flow distribution among the solar collector absorber tubes, and as a first step to any detailed analysis of the influence of flow on heat transfer in the collector and on its consequent thermal performance, this study investigates the distribution of flow through a typical system consisting of two manifolds connected by a number ...

Prior to rotary coring, a range of soft-sediment coring tools were deployed to recover the sediment-water interface and the upper few metres of strata, whose integrity was threatened by embedment of the sea riser for drilling of the ANDRILL (AND)-1A/1B holes. These coring options included (1) a sediment gravity corer deployed through the ice-shelf hole, and (2) a push corer deployed through the...

Abstract The flow field induced by internal solitary waves (ISWs) is peculiar wherein water motion occurs in the whole depth, and strong shear near pycnocline can be generated due to opposite direction between upper lower layers, which a potential threat marine risers. In this paper, of ISWs obtained with Korteweg-de Vries (KdV) equation for two-layer fluid system. Then, linear analysis perform...

The kurtosis statistic is introduced as a sensitive tool for efficient preliminary analysis of flowinduced vibration response data. The kurtosis of sequential blocks of time series data allows one to distinguish single mode lock-in events. The problem of predicting lock-in is then discussed. Instructional examples are introduced to illustrate the relative importance of flow-speed, power-in leng...

This paper presents results obtained as part of the DeepStar Phase 10 program on VIV Factors of Safety. The objective was to develop a general methodology to calibrate Factors of Safety for VIV-induced fatigue and to apply it to partially straked risers. This was achieved using reliability methods, accepted industry VIV prediction software and state-of-the-art model test experiments. Most oil c...