The coupling effect between the offshore platform and riser in platform-riser multi-body system might be greatly increased under heavy external maritime stresses. will become significantly more nonlinear. partial secondary development of OrcaFlex is carried out considering strong non-linearity dynamic positioning (DP) system, combined with actual construction engineering background lumped mass ...

This work investigates the impact of elevation on terrain-induced slugging in a riser system. Fluid compositions were modeled with multiflash and exported to OLGA readable PVT Table File. Pipeline materials properties geometry different develop flowline model. Two geometries (1 2) elevations defined establish their effect accumulated liquid volume flow, surge volume, slug length, number slugs d...

The fatigue reliability assessment of deepwater risers plays an important role in the safety oil and gas development. Physical-based models are widely used riser analyses. However, these present some disadvantages analyses, such as low computational efficiency inability to introduce inspection data. An improved analysis method was proposed conduct risers. data-driven were established based on r...

Marine organisms modify the distribution of radioisotopes in the oceanic ecosystem. Various vital processes of plants and animals concentrate elements. The distributions of the biota are often independent of their watery environment; they may actively migrate vertically or horizontally or may remain in place while the water moves past them. In the case of plankton, the concentrating organisms p...

The aim of the research was to summarize a mathematical model of bow and arrow interaction in the vertical plane and to develop an appropriated computer model. A bow was modeled as a non-deformed riser and hinged to it two nondeformed limbs with Archimedean springs. Their stiffness as well, as an elasticity of a string was taken into account in a linear approach. An asymmetric bow scheme was co...

FCC riser; Computational fluid dynamics (CFD); Cracking reaction kinetics; Hydrodynamics; 4-Lump kinetic model; k-Epsilon turbulence model Abstract Fluid catalytic cracking (FCC) is an essential process for the conversion of gas oil to gasoline. This study is an effort to model the phenomenon numerically using commercial computational fluid dynamics (CFD) software, heavy density catalyst and 4-...

Flexible cylinders, such as marine risers, often experience sustained vortex-induced vibrations (VIVs). Installing helical strakes on a riser is the most widely used technique to mitigate VIVs. This study was inspired by giant Saguaro Cacti which can withstand strong wind with shallow root system. In this study, numerical simulations of flow past stationary cylinder cactus-shaped cross-section ...

We investigate three-dimensional problems in solid mechanics with stochastic loading or material properties. To solve these problems, we use a spectral expansion of the solution and random inputs based on Askey-type orthogonal polynomials in terms of independent, identically distributed (i.i.d) random variables. A Galerkin procedure using these types of expansions, the generalized Polynomial Ch...

The present work focuses on developing correlations for better prediction of solids holdups in the fully developed region of cocurrent upflow and downflow two-phase flow. Systematic experiments were carried out in two CFB risers (15.1m and 10.5m high, respectively, but with the same 0.1 m i. d.) and a 9.3 m high, 0.1 m i. d. CFB downer. The experimental results obtained from about 200 sets of o...

In order to predict the performance of a riser sleeve using simulation software, the thermophysical properties of that sleeve must be known. Current literature gives little to no information about these properties. Some manufacturers have given these properties as an optional module for simulation software without revealing their actual values. The accuracy of these “black box” properties is un...