Longbin Tao

University of Strathclyde · Department of Naval Architecture and Marine Engineering

This paper proposes an enhanced Weibull-Corrosion Covariate model for reliability assessment of a system facing operational stresses. The newly developed model is applied to a Subsea Gas Compression System planned for offshore West Africa to predict its reliability index. System technical failure was modelled by developing a Weibull failure model i...

For the successful deployment of large scale tidal turbine arrays occupying a large part of tidal channels, understanding the effects of wake interaction in densely spaced arrays is of importance. A comprehensive set of experiments has been conducted with scaled tidal turbines to investigate the resulting wake characteristics in a number of differe...

Direct numerical simulations are performed for the uniform flow around an inclined circular disk. The diameter–thickness aspect ratio ( ) of the disk is 50 and the inclination angle ( ) is considered over the range of , where refers to the condition where the flow is normal to the disk. The Reynolds number ( ), based on the short axis of projection...

A comprehensive numerical study on flow-induced motions (FIMs) of a deep-draft semi-submersible, a typical multiple cylindrical structure in offshore engineering, was carried out to investigate the energy transformation of the vortex shedding process. In addition, the corner shape effect on the flow characteristics, the hydrodynamic forces, and the...

Heave plates have been widely utilized in floating offshore structures as they can provide additional damping and added mass to improve the hydrodynamic response of the system. This study investigates the hydrodynamic characteristics (added mass and damping) of oscillatory solid or porous disks using model scale experiments. All experiments were co...

This paper presents a benchmarking study of four floating wind platform’ motion and dynamic tension responses to verify an innovative design with the intention of overall cost reduction of a durable, reliable, safe design. An aero-hydro-servo-elastic code is applied to benchmark a 10 MW tension leg buoy (TLB) floating wind turbine to the current le...

In this paper, we focus on the two-dimensional pulsating nanofluid flow through a parallel-plate channel in the presence of a magnetic field. The pulsating flow is produced by an applied pressure gradient that fluctuates with a small amplitude. A kind of proper transformation is used so that the governing equations describing the momentum and therm...

During operation and maintenance of the offshore wind farms, some regular inspections for the wind turbines are performed by remotely operated underwater vehicles (ROV) and service operation vessels (SOV). However, the ROV often experiences excessive motions as it passes through wave zone due to wave-ROV interaction combined with free surface effec...

As part of the ongoing development of the Stiesdal Offshore A/S TetraSub floating offshore wind turbine generator (WTG) platform, this study investigates wave run-up acting on the front cylindrical ballast tanks. Using experimental results from a recent test campaign of a TetraSub variant 1:50 scale model, this work aims to review existing semi-emp...

As a signatory to the Paris Agreement, the UK is committed to contribute efforts to prevent global temperature increase. The UK set its policies and proposals to meet zero net strategy by 2050. Offshore green hydrogen is one promising approach to transfer offshore wind energy to onshore demand areas due to its clean and high-power density. The UK i...

The offshore renewable energy sector has seen a rise in floating devices, all of which require mooring and anchoring systems. Synthetic ropes have emerged as a promising technology for cost reduction in this system. However, characterising the behaviour of these materials, which exhibit complex non-linear, visco- elastic and plastic structural prop...

Liquid viscosity has a potential effect on bubble dynamics. This paper is concerned with bubble dynamics in a compressible viscous liquid near the free surface. The liquid-gas flow is modeled using the Eulerian finite element method (EFEM) coupled with the volume of fluid method (VOF). The numerical results have been shown to be in excellent agreem...

The peridynamic (PD) theory is based on nonlocal mechanics and employs particle discretization in its computational domain, making it advantageous for simulating cracks. Consequently, PD has been applied to simulate ice damage and ice–structure interaction under various conditions. However, the calculation efficiency of PD, similar to other meshles...

Bolted ring flange connections are widely utilized in offshore wind turbines to connect steel tubular segments. After the massive production and installation of offshore wind turbines in the past decade, flatness divergence is regarded as one of the most important initial imperfections for the fatigue design of flange connections. Offshore wind tur...

Fatigue failure is an important issue for offshore wind turbine support structures. Especially, fully coupled time domain analysis will lead to high computational burden. Therefore, accurate and efficient fatigue evaluation methods have always been the common goal pursued by the industry and researchers. This paper evaluates fatigue damage under co...

During the massive manufactures and installations of fixed offshore wind turbines in China, initial imperfections were often found in the inspection. As more and more attentions and efforts of the wind energy sector have been devoted to deep waters with fixed and floating wind turbines (FWTs), the impact of such initial imperfections on fatigue ass...

The operation and maintenance (O&M) of an offshore wind turbine consumes large percentage of cost in the whole life of the offshore wind project. In most maintenance strategies, the service operation vessels (SOV) are widely employed in the maintenance activities. So far, the SOVs are large vessels to satisfy the requirement of equipment and functi...

The existence of a moonpool may affect motion characteristics and stability of a drillship. This paper presents numerical and experimental study on the influence of the configuration of a moonpool on the motion performance and stability of a drillship under the condition of a constant displacement. Ship hydrostatics and three-dimensional (3D) poten...

The computational investigation on the ice cover fragmentation under extreme loadings, such as a shock wave, is still a poorly understood research topic. In this process, the influence of the temperature change on the crack evolution, and the damage of the ice cover can be significant since the temperature is one of the critical factors affecting i...

The deployment of offshore wind turbines has focused primarily on shallow seas (such as the North Sea, Chinese coastal waters, and the New England coast) using bottom fixed foundations. However, much of the world’s offshore wind resource lies in deeper waters where bottom-fixed foundations are not suitable, and floating platforms must be utilised....

Heave plates exert a unique influence on the motions of marine structures floating in seas or oceans. Due to their low thickness and sharp edges, the hydrodynamic performance of these plates is influenced by such physical and oscillatory parameters as the Keulegan–Carpenter (KC) number, frequency, perforation ratio, cavity arrangement, cavity size,...

The decarbonisation of waterborne transport is arguably the biggest challenge faced by the maritime industry presently. By 2050, the International Maritime Organization (IMO) aims to reduce greenhouse gas emissions from the shipping industry by 50% compared to 2008, with a vision to phase out fossil fuels by the end of the century as a matter of ur...

The integration of wave energy devices and coastal structures may be an innovative and sustainable way to achieve energy production purposes with a secondary benefit of coastal protection, which can increase accessibility and reduce the costs of wave energy technology. In this paper, a 3-D theoretical model was developed to investigate the hydrodyn...

By using wave energy dissipating/capturing capability of the perforated structure 9 and wave absorbers to reduce the wave reflection from the harbor/coast, this paper describes 10 a theoretical study on the hydrodynamic performance of a novel OWC structure, comprising of 11 a harbor/coast-based OWC device provided with a surface-piercing perforated...

Surface elevation around multiple column offshore structure is an important phenomenon crucial to air gap design of offshore platforms. This paper investigates the competing hydrodynamic phenomena, i.e., wave run-up of surface elevation rising along the column and near-trapping – the increase of surface elevation due to near-resonance among the col...

This study aims to develop an efficient and accurate analytical-numerical model to analyze full interaction between seawater waves and cylindrical floating breakwaters in an infinite fluid domain of finite arbitrary water depth. Based on potential flow assumption, a semi-analytical Scaled Boundary Finite Element Method (SBFEM) in a two-dimensional...

The bow shape is the most critical factor to determine the icebreaking performance of an icebreaker. Mechanism study on the icebreaking process for different bow types is necessary for the initial design of the icebreaker hull form. This paper proposed an ice-ship interaction model based on the meshfree method, Peridynamics, in which the geometric...

Along with the technology development of ocean resources, offshore platforms are gradually becoming larger and more complex. Recent development of the oil and gas field in the deep-water region often involves multiple floating platforms adjacent to each other to perform more complex functions for oil and gas production. This paper describes the inv...

This study aims to develop an efficient and accurate analytical-numerical model to analyze full interaction between seawater waves and cylindrical floating breakwaters in an infinite fluid domain of finite arbitrary water depth. Based on potential flow assumption, a semi-analytical Scaled Boundary Finite Element Method (SBFEM) in a two-dimensional...

The existence of ice and its interaction with structure greatly threaten the navigation of the icebreaker. Due to the damage characteristics of ice, the traditional numerical ways based on mesh method are challenging to solve ice-structure interaction. The nonlocal particle methods have increasingly gained popularity as an essential tool for calcul...

Purpose The purpose of this paper is to investigate the immiscible two-layer heat fluid flows in the presence of the electric double layer (EDL) and magnetic field. The effects of EDL, magnetic field and the viscous dissipative term on fluid velocity and temperature, as well as the important physical quantities, are examined and discussed. Design/...

An iterative time-marching scheme is developed to investigate the hydrodynamic interactions between multiple ships. Such an unsteady interactive effect could be magnified in restricted waterways, e.g., a channel or harbor area. To the author’s knowledge, nearly all the research on the ship-to-ship interaction neglecting the free surface effects. Th...

Offshore floating wind turbines (FWTs) in deep water experience cyclic loadings from both environment and mechanical operations. For FWTs, the upper turbine and tower are mainly subjected to wind loading; and the floater is subjected to wave forces. It has been widely accepted that there is a strong coupling between the floater motions and the turb...

Violent pulsating bubbles behave diversely in different circumstances. It is a multi-scale problem in both space and time. In 3-D problems, the numerical simulation is usually too expensive to implement in practice with a fixed grid. In this paper, a 3-D multi-fluid model is established based on the Eulerian finite element method and the adaptive m...

Sea-keeping model tests of ships based on transient waves have been widely applied over the past several decades. In order to obtain response amplitude operators (RAOs) of a ship, most of the post-processing of the experimental data uses the fast Fourier transform (FFT) to obtain the wave spectrum and the corresponding response spectrum. However, f...

Along with the development in arctic region, the icebreaking technologies are gradually becoming the focus. As one of the most powerful and effective way to breaking ice, especially in the ability to solve ice jams, the study of the behaviour of the sea and river ice under dynamic loads is an urgent subject of scientific research and it attracts ex...

The climate change may affect the long-term wave statistics and consequently affect the cumulative fatigue damage. This paper aims to project the trend of annual fatigue damage of offshore floating structures and to detect the climate change impact on the future fatigue damage by coupling a conventional fatigue design method with climate and wave m...

Vortex flow around multiple columns of finite length is ubiquitous in engineering. The present work focuses on the basic fluid physics in terms of the vortex shedding flow patterns and their dependence on structural configurations and flow parameters. Though widely documented in the literature, there is no consensus on certain aspects of the wake c...

Flow and heat transfer of a nanofluid through a horizontal microchannel in the presence of the magnetic field effects and electric double layer (EDL) is investigated theoretically. For a microchannel with a large aspect ratio, the flow problem is treated as a two-dimensional nonlinear system. The body force generated by the EDL and magnetic field i...

The damage effects of an underwater explosion have always been a crucial problem in the ship mechanics. Notably, the bubble evolution and the jet impact load are one of the most difficult parts in the shock-resistance design of ship structures due to the discontinuities and significant nonlinear deformation. In this paper, the Eulerian finite-eleme...

The energy dissipation mechanisms of bubble pulsation in compressible fluids have always been a significant aspect of research into bubble dynamics. In this paper, bubble dynamics in compressible fluids are investigated numerically with the Eulerian finite-element method (EFEM), and the energy dissipation due to the wave effects of the compressible...

Plunging breakers could induce one of the most devastating forces on an offshore structure. As compared to non-breaking wave, a plunging breaker would induce an additional slamming load on an offshore structure. Current industry guidelines for design breaking wave slamming coefficient do not take into account of the geometric cross section of the o...

A simple mathematical model was developed based on the single-degree-of-freedom analogy and principle of conservation of energy evaluating various modes of Vortex-Induced-Vibration (VIV) of a jack-up with cylindrical legs in steady flow. Mass ratio, damping ratio and mode factor were found to be the important parameters controlling the inline and c...

Understanding the dynamics of oscillating bubbles beneath a free surface is crucial to many practical applications including airgun-bubble clusters, underwater explosions, etc. In this paper, an experimental and numerical study of the dynamic behaviors of a coalesced bubble near a free surface is conducted, which shows quite different physical feat...

Leading-edge tubercles have been investigating widely on the performance of foils in the last decade. In this study, the biomimetic tubercle design has been applied to the corner shape on a deep-draft semi-submersible. A numerical study on flow over a deep-draft semi-submersible (DDS) with a biomimetic tubercle corner shape was carried out to inves...

A simple mathematical model is developed based on the single-degree-of-freedom analogy and principle of conservation of energy evaluating various modes of Vortex-Induced-Vibration (VIV) of a jack-up with cylindrical legs in regular waves. Similar to uniform current, mass ratio, damping ratio and mode factor are found to be the important parameters...

Plunging breakers, unlike non-breaking waves, impose additional slamming load on the offshore structures. This additional slamming load is considered an extreme event and is one of the most devastating forces that an offshore structure could encounter during its operational lifecycle. Whilst there are design guidelines for offshore structures perta...

Along with the development in offshore technology, the offshore platforms are gradually becoming larger and more complex. Recent development of oil and gas field in the deepwater region often involves multiple floating platforms adjacent to each other. Wave free surface associated with the air-gap design is one of the most important issues as the i...

The main drivers for the continued decarbonisation of the global energy market are renewable energy sources. Moreover, the leading technological solutions to achieve this are offshore wind turbines. As installed capacity has been increasing rapidly and shallow water near shore sites are exhausted, projects will need to be developed further from sho...

In this study, numerical analysis has been carried out to investigate the hydrodynamic interactions of two multi-columns platforms. The objective of the work is to preliminarily evaluate the feasibility of a tension-leg-platform (TLP) dry tree unit (DTU) with tender assisted drilling (TAD) from the aspect of vortex-induced motions, characterized by...

The spatial localized influence of wind on wave induced load on a flexible cylinder has been assessed throughout a test series conducted in a wave-wind-current flume at Newcastle University. The tests are motivated from other experimental and numerical investigations showing air flow separation on the leeward side of steep waves that can lead to ad...

The Boundary Integral Method (BIM) has been widely and successfully applied to cavitation bubble dynamics; however, the physical complexities involved in the coalescence of multiple bubbles are still challenging for numerical modeling. In this study, an improved three-dimensional (3D) BIM model is developed to simulate the coalescence of multiple c...

A ring-shaped spar-type Very Large Floating Structure (VLFS) is proposed as an intermediate base for supporting deepwater resource exploitation far away from the coast line. The proposed VLFS is composed of eight rigidly connected deep-draft spar-type modules and an inside harbor. A double-layered perforated-wall breakwater is vertically attached t...

The flooding of a damaged ship in waves is a complex process, often coupled with the internal and external liquid motion together with the ship hull motion. Paramount to the operation safety, in order to improve the prediction accuracy of ship motion during the flooding process, the strip theory is applied to study the dynamic response of the damag...

The behaviour of microchannel flow of a nanofluid between two parallel flat plates in the presence of the electrical double layer (EDL) is investigated in this paper. The problem is formulated based on the Buongiorno nanofluid model with the electrical body force due to the EDL being considered in the momentum equation. As one of the highlights of...

Electricity generation from tidal current can provide a reliable and predictable addition to a reduced carbon energy sector in the future. Following the deployment of the first multi-turbine array, significant cost reduction can be achieved by moving beyond demonstrator projects to large scale tidal turbine arrays. The interactions between multiple...

A numerical study on flow over a stationary deep-draft semi-submersible (DDS) with various corner shapes was carried out to investigate the corner shape effects on the overall hydrodynamics. Three models based on a typical DDS design with different corner shapes were numerically investigated under 45° incidence. The present numerical model has been...

Dynamic position (DP) control and pipeline dynamics are the two main parts of the deepwater S-lay simulation model. In this study, a fully coupled analysis tool for deepwater S-lay deployment by dynamically positioned vessels is developed. The method integrates the major aspects related to numerical simulation, including coupled pipeline motion and...

One important kinematic properties of breaking waves is the wave celerity. Constant wave celerity has been used for the wave breaking criterion by many researchers. However, this approach does not consider the variation of wave celerity at different phases before breaking. Hence, this article examines the aspects of the wave breaking criterion and...

Multiple Column Platform (MCP) semi-submersible is a newly proposed concept, which differs from the conventional semi-submersibles, featuring centre column and middle pontoon. It is paramount to ensure its structural reliability and safe operation at sea, and a rigorous investigation is conducted to examine the hydrodynamic and structural performan...

An excellent vortex suppression device, in the form of an antinode fairing is presented towards reducing the VIV of structural members exposed to flow. An analytical procedure is also developed to optimise the length and location of fairings. Two fairing sections are tested on cylindrical legs of a Jackup model and the results are compared with the...