Thorsten Stoesser

• PhD
• Professor at University College London

Deep-sea mining offers significant opportunities but also presents substantial challenges, particularly due to the complex seabed environments that exhibit highly rheological and uncertain soil behavior, which surpasses the scope of traditional geotechnical models. This Special Issue addresses the intertwined geotechnical, geological, and environme...

A scenario in which waves interact with two side-by-side floating bodies placed in close proximity holds significance in context to offloading of liquefied natural gas as well as floatover installation operations. The scenario becomes particularly challenging in beam-sea conditions and when the bodies have different draft and/or length. In the pres...

The Office of Naval Research Tumblehome (ONRT) is a stealth destroyer ship that is characterized by a wave-piercing hull design as well as a large sail area. The literature indicates that the bare hull accounts for ~80% of the ship's total resistance across the entire range of cruising speeds. A majority of the literature studies dealing with CFD s...

In this paper, the results of numerical simulations of open-channel flow through boulder arrays at varying Froude numbers are reported. The simulations aim at clarifying the role of the Froude number on flow, turbulence, and hyporheic exchange. At low and intermediate Fr, the boulder top is above the water surface, and time-averaged streamwise flow...

Increasing global energy demands necessitate the exploitation of ocean resources, including oil and gas, hydrates, polymetallic nodules, and rare-earth minerals, as well as marine renewable energy such as wind power, tidal energy, and wave energy. However, due to the complex interplays between geologic materials and the marine hydrodynamic environm...

In October 2021, the editorial office invited Prof. Xiaolei Liu, from the Ocean University of China, Prof. Thorsten Stoesser, from University College London, and Dr. Xingsen Guo, from University College London, to serve as guest editors for the special issue titled “Advances in Marine Engineering: Geological Environment and Hazards” [1]. Their task...

Dear Colleagues, With the continuous advancement of estuarine, coastal, offshore, and deep-sea engineering construction (such as marine resource development, offshore wind power projects, and deep-sea mining engineering) and environmental protection efforts, research on geological and hydrodynamic environments and hazards has gradually deepened, le...

Time-averaged velocity fields in uniform open-channel flows over rough beds may exhibit spatial heterogeneities due to the effects of bed roughness and secondary currents (SCs). The latter typically originate from the turbulence anisotropy and spatial heterogeneity introduced by the solid and mixed corners (i.e., between sidewalls and water surface...

The study of cloud and droplet dynamics during potential transmission events, such as coughing, is essential for understanding the spread and deposition of aerosols and droplets carrying airborne diseases. This paper reports the refinement of a complex model that couples momentum, temperature, and humidity for accurately simulating the dynamics of...

Wave return seawalls are structures designed to protect the leeward side from overtopping due to the action of waves. The numerical modelling of breaking waves on fully reflective structures like wave return seawalls are challenging due to the complex fluid dynamics involved, air-water mixture's interaction due to air entrapment and air entrainment...

The method of large-eddy simulation (LES) coupled with the density transport equation is employed to simulate the evolution of a gravity-driven high-density turbidity current and its interaction with a pair of parallel suspended pipes. The LES method is validated first using data of a non-Boussinesq lock-exchange experiment and satisfying agreement...

The results of large-eddy simulations of open-channel flows over spanwise heterogeneous surface ridges at two representative spanwise spacings are presented. Flows at moderate Froude and Reynolds numbers over smooth channel beds with streamwise-orientated rectangular ridges are considered. The ridge spacing has a profound effect on the flow: at sma...

Time-averaged velocity fields in uniform open-channel flows over rough beds may exhibit local spatial heterogeneities due to the effects of bed roughness and secondary currents (SCs). The latter typically originate from the turbulence anisotropy and spatial heterogeneity introduced by the solid and mixed corners (i.e., between sidewalls and water s...

The results of large-eddy simulations of free-surface turbulent channel flow over spanwise-aligned square bars are used to investigate the effects of bed roughness and water surface deformations on the root-mean-squared velocity fluctuations, dispersive shear stress, double-averaged Reynolds shear stress, wake kinetic energy and double-averaged tur...

The water surface response to subcritical turbulent flow over a backward-facing step (BFS) is studied via high-resolution large-eddy simulation (LES). The LES method is validated first using data of previously reported experiments. The LES-predicted water surface is decomposed into different types of gravity waves as well as turbulence-driven force...

With the continuous advancement of coastal, offshore, and deep-sea engineering construction (e.g., marine oil, gas, and mineral resource development, offshore wind power projects), associated studies on marine geological environments and hazards have also advanced in parallel. This Special Issue (SI) was organized by Prof. Xiaolei Liu from the Ocea...

With the continuous advancement of coastal, offshore, and deep‐sea engineering construction (e.g., marine oil, gas, and mineral resource development, offshore wind power projects), associated studies on marine geological environments and hazards have also advanced in parallel. This Special Issue (SI) was organized by Prof. Xiaolei Liu from the Ocea...

In this paper, the method of computational fluid dynamics (CFD) is proposed to simulate a fluidized submarine landslide with shear thinning non-Newtonian fluids over a seabed under different contact conditions in the ambient water. The CFD method is first validated using data of physical channel and non-Boussinesq lock-exchange experiments with dif...

Dear Colleagues, With the continuous advancement of coastal, offshore, and deep-sea engineering construction (marine resource development, offshore wind power projects, etc.), research on marine geological environments and hazards has gradually deepened and many research advances have been achieved. Therefore, this Special Issue has been organized...

Submarine landslide-ambient water-pipeline interactions are receiving extensive attention in ocean engineering, especially the impact forces caused by landslides on pipelines. Computational fluid dynamics (CFD) approaches are widely used to obtain these forces; however, as necessary definite solution conditions, the boundary conditions of CFD model...

Large-eddy simulations of free surface turbulent channel flow over spanwise-aligned square bars with transitional and k-type spacing are performed. Differences in the sign of spatial and temporal velocity fluctuations entail sweep and ejection events which contribute to the dispersive and Reynolds shear stress only in flow over k-type roughness. Th...

Results of large-eddy simulations of laminar, transitional and turbulent free surface flow at constant Froude number over spanwise-aligned square bars are analyzed. Two different bar spacing corresponding to transitional and k-type roughness are selected. The water surface deformations include mild undulation in flow over transitional roughness and...

Large-eddy simulations (LES) of supercritical flow in a straight-wall, open-channel contraction of 6° and contraction ratio of 2:1 are performed. The LES code solves the filtered Navier-Stokes equations for two-phase flows (water-air) and employs the level-set method. The simulation was validated by replicating a previously reported experiment. Con...

Large-eddy simulations of turbulent flow in partially filled pipes are conducted to investigate the effect of secondary currents on the friction factor, first- and second-order statistics and large-scale turbulent motion. The method is validated first and simulated profiles of the mean streamwise velocity, normal stresses and turbulent kinetic ener...

The mean and instantaneous flow separation of two different three-dimensional asymmetric diffusers is analysed using the data of large-eddy simulations. The geometry of both diffusers under investigation is based on the experimental configuration of Cherry et al. (Int J Heat Fluid Flow 29(3):803–811, 2008). The two diffusers feature similar area ra...

With the goal to explore the effects of natural bed roughness on bedload transport, numerical simulations of flow and particle saltation are carried out with varying bed roughness and particle spatial density. A combination of Eulerian and Lagrangian point‐particle methods is applied to solve the equations of motion of the fluid and the particles w...

Reynolds and dispersive shear stresses in turbulent flow over spanwise-aligned square bars in an open channel flow are examined. Results of large-eddy simulation of flow over two different bar spacings corresponding to transitional and k -type (reattaching flow) roughness are analyzed. The Reynolds shear stress contribution to the momentum loss (or...

This paper presents a three-dimensional (3D) non-hydrostatic model for the prediction of the interaction between nonlinear waves and fixed floating structures. The model solves the incompressible Euler equation by use of a semi-implicit, fractional step algorithm. The water surface elevation is treated as a single-valued function of horizontal posi...

A conservative and consistent three-dimensional Cartesian cut-cell method is presented for reducing the spurious pressure oscillations often observed in moving body simulations in sharp interface Cartesian grid methods. By analysing the potential sources of the oscillation in the cut-cell framework, an improved moving body algorithm is proposed for...

Large eddy simulations (LESs) of turbulent flow in partially filled pipes at various filling degrees are conducted to investigate the response of the water surface to the turbulence and the secondary flow below it. LESs are validated first using experimental and direct numerical simulation data. At increasing water depth, the magnitude of water sur...

This paper presents results of a solitary wave propagating over a submerged horizontal plate based on a non-hydrostatic model. A high-resolution advection scheme is employed based on a second-order flux-limiter method. The model is first validated by comparing numerical results with recently obtained measured data. Then, a series of simulations are...

The interaction between submarine landslides and pipelines has attracted widespread attention. For a pipeline designer, generalizing practical analysis models, obtaining accurate dynamic forces (i.e., the drag force and lift force), and proposing effective pipeline protection measures are prerequisites for ensuring their safe operation. In this pap...

The effect of pipeline surface roughness on the interaction between submarine landslides and pipelines may not be insignificant and has rarely been quantified. In this paper, a previously validated computational fluid dynamics model is employed to study the interaction of submarine landslides and suspended or laid-on-seabed pipelines, respectively,...

Wind energy utilization in urban areas revives the interests in vertical axis wind turbine (VAWT). An upstream deflector has demonstrated to increase the overall efficiency of two closely spaced VAWTs more than 30% in previous experiment research. However, the optimal geometrical configuration and the mechanisms driving the performance improvement...

A three-dimensional numerical wave tank (NWT) based on the large eddy simulation (LES) code Hydro3D is introduced. The open-source code employs the level set and immersed boundary methods in order to compute the water surface and to account for solid structures in the numerical tank, respectively. The spatially-filtered Navier–Stokes (N-S) equation...

A three-dimensional (3D) numerical study is undertaken to investigate dam-break flows over 3D structures. A two-phase flow model has been developed within the large-eddy simulation (LES) framework. The governing equations have been discretized using the finite-volume method, with the air-water interface being captured using a volume-of-fluid method...

Large-eddy simulations of free surface flow over bed-mounted square bars are performed for laminar, transitional and turbulent flows at constant Froude number. Two different bar spacings are selected corresponding to transitional and k-type (reattaching flow) roughness, respectively. The turbulent flow simulations are validated with experimental da...

This paper presents ISOPE’s 2020 comparative study on the interaction between focused waves and a fixed cylinder. The paper discusses the qualitative and quantitative comparisons between 20 different numerical solvers from various universities across the world for a fixed cylinder. The moving cylinder cases are reported in a companion paper as part...

A three-dimensional numerical study has been undertaken to investigate the interactions of a steep focused wave and a vertical circular cylinder. The large-eddy simulation approach has been adopted in this study, where the model is based on the filtered Navier–Stokes equations, with the dynamic Smagorinsky subgrid model being used for the unresolve...

A multiphase flow numerical approach for performing large-eddy simulations of three-dimensional (3D) wave-structure interaction is presented in this study. The approach combines a volume-of-fluid method to capture the air-water interface and a Cartesian cut-cell method to deal with complex geometries. The filtered Navier–Stokes equations are discre...

For the purpose of this paper, the in-house large-eddy simulation code, Hydro3D, is refined to study wave structure interaction. First of all, the code is used to develop a numerical wave tank capable of simulating accurately the generation, progression and damping of solitary waves in a tank. Then, Hydro3d is employed to simulate a previous labora...

In order to investigate the effect caused by floating bodies on vortex-induced vibration (VIV) of risers, a composite pipe with the aspect ratio of 250 is tested under coupled uniform and shear oscillatory flow, with Reynolds number ranging from 2000 to 24000. The characteristics of VIV amplitude and frequency of the model under uniform flow are co...

A two-phase flow model is employed to study three-dimensional (3D) breaking of solitary waves over surface-piercing and submerged conical structures. Details of the wave pre-breaking, overturning, and post-breaking processes are included. The governing equations are discretized by the finite volume method and the PISO algorithm is utilized for the...

A three-dimensional Cartesian cut-cell method for the large-eddy simulation of two-phase flows with moving bodies is presented in this study, which combines a volume-of-fluid method to capture the air-water interface and a moving body algorithm on a stationary, non-uniform, staggered, Cartesian grid. The filtered Navier–Stokes equations are discret...

In this paper we report on the design and testing of a novel vertical axis wind turbine (VAWT) system. The system consists of two counter-rotating VAWT rotors and a deflector that is placed between the two rotors. The system’s performance is first quantified in wind tunnel experiments and subsequently, three-dimensional computational fluid dynamics...

An actuator surface model (ASM) to be employed to simulate the effect of a vertical axis turbine on the hydrodynamics in its vicinity, particularly its wake is introduced. The advantage of the newly developed ASM is that it can represent the complex flow inside the vertical axis turbine’s perimeter reasonably well, and hence, is able to predict, wi...

Large eddy simulations (LESs) are performed for turbulent flow through and around a porous patch of thin vertical plates at a plate Reynolds number of R e p =5,800. The plates are arranged in a staggered pattern, presenting an elliptical planform and mimicking streamwise‐oriented blades of emergent vegetation. The immersed boundary method is employ...

Knowledge of rough-bed flows is important for river engineers and environmental scientists alike asmost natural surface water flows are considered within the hydraulically rough flow regime. This study helps our understanding of flow characteristics above a rough gravel riverbed, which in-turn, affect fine sediment and nutrient transport which can...

A theoretically based relationship for the Darcy–Weisbach friction factor $f$ for rough-bed open-channel flows is derived and discussed. The derivation procedure is based on the double averaging (in time and space) of the Navier–Stokes equation followed by repeated integration across the flow. The obtained relationship explicitly shows that the fri...

Results of an experimental study into steady uniform flows in compound open channels with cylindrical obstructions designed to mimic emergent vegetation is presented. Two configurations—fully covered floodplain and one-line obstructions—are considered, and the hydraulic properties are compared to those of a smooth, unobstructed compound channel. Pa...

Evaluating the interactions between offshore structures and extreme waves plays an essential role for securing the survivability of the structures. For this purpose, various numerical tools—for example, the fully nonlinear potential theory (FNPT), the Navier–Stokes (NS) models, and hybrid approaches combining different numerical models—have been de...

Results from Blind Test Series 1, part of the Collaborative Computational Project in Wave Structure Interaction (CCP-WSI), are presented. Participants, with a range of numerical methods, simulate blindly the interaction between a fixed structure and focused waves ranging in steepness and direction. Numerical results are compared against correspondi...

The method of large eddy simulation (LES) was employed to investigate the flow and turbulence structure around bridge abut-ments of different lengths placed in a compound, asymmetric channel. The simulations were faithful representations of large-scale physical model experiments that were conducted in the hydraulics laboratory at the Georgia Instit...

A large-eddy simulation (LES) of a laboratory-scale horizontal axis tidal stream turbine operating over an irregular bathymetry in the form of dunes is performed. The Reynolds number based on the approach velocity and the chord length of the turbine blades is approximately 60,000. The simulated turbine is a 1:30 scale model of a full-scale prototyp...

Results from Blind Test Series 1, part of the Collaborative Computational Project in Wave Structure Interaction (CCP-WSI), are presented. Participants , with a range of numerical methods, simulate blindly the interaction between a fixed structure and focused waves ranging in steepness and direction. Numerical results are compared against correspond...

A large-eddy simulation-actuator line method (LES-ALM) applied to a single horizontal axis tidal turbine is presented and validated against experimental data. At a reasonable computational cost, the LES-ALM is capable of capturing the complex wake dynamics, such as tip vortices, despite not explicitly resolving the turbine’s geometry. The LES-ALM i...

Near-bed and pore space turbulent flows are beginning to be understood using new technologies and advances in direct numerical simulation (DNS) and large-eddy simulation (LES) techniques. However, the riverbed geometry that is used in many computational studies remains overly simplistic. Thus, this study presents the development of an artificial re...

The wake recovery downstream of a vertical axis turbine operating in a turbulent channel flow is investigated via detailed velocity measurements using an Acoustic Doppler Velocimeter. Three distinct wake regions are identified: (i) a near-wake region which extends until two rotor diameters (2D) downstream and characterised by a low-momentum area is...

Eulerian-Lagrangian approaches capable of accurately reproducing complex fluid flows are becoming more and more popular due to the increasing availability and capacity of High Performance Computing facilities. However, the parallelisation of the Lagrangian part of such methods is challenging when a large number of Lagrangian markers are employed. I...

A large-eddy simulation based Eulerian-Lagrangian model is employed to study bubble plumes in an open channel with crossflow. The numerical results are validated with PIV experimental data. Good agreement between simulated and observed velocities is found. The impact of the crossflow on the structure of the plume and the resulting turbulent structu...

In this study a thermal camera was used to inferring the properties of thermal turbulent structures at the water surface of an array of emergent vertical cylindrical obstacles located in staggered fashion at one side of an open channel flow. Three different diameters (D = 1.25 cm, 2.5 cm and 5.0 cm) were tested. A thermal camera SC640 was used to r...

In this study a thermal camera was used to inferring the properties of thermal turbulent structures at the water surface of an array of emergent vertical cylindrical obstacles located in staggered fashion at one side of an open channel flow. Three different diameters (D = 1.25 cm, 2.5 cm and 5.0 cm) were tested. A thermal camera SC640 was used to r...

This study focuses on the impact of relative depth Dr, on the shear layer geometry and mixing width in compound channel uniform flows using a thermography technique. FLIR’s image processing software together with Mat lab software was used to extract process and analyses water surface temperature distribution data. Results showed that for the interm...

This study focuses on the impact of relative depth, D r , on the shear layer geometry and the mixing width in compound channel uniform flows using a thermal camera. The results coincide with the results of Tominaga and Nezo (1991).

This study focuses on the impact of relative depth D r , on the shear layer geometry and mixing width in compound channel uniform flows using a thermography technique. FLIR's image processing software together with Mat lab software was used to extract process and analyses water surface temperature distribution data. Results showed that for the inte...

Two different processes occurring in riverbeds and effecting the aquatic habitat were investigated in this study: colmation and decolmation of suspended sediment. Flume laboratory experiments were carried out and analysed to study velocity profiles above smooth and gravel beds.

Seminar at the Institut national des sciences appliquées de Lyon, Lyon, France

The results of large-eddy simulations of flow and transient solute transport over a backward facing step and through a 180° bend are presented. The simulations are validated successfully in terms of hydrodynamics and tracer transport with experimental velocity data and measured residence time distribution curves confirming the accuracy of the metho...

Results from large-eddy simulations and complementary flume experiments of turbulent open channel flows over bed-mounted square bars at intermediate submergence are presented. Scenarios with two bar spacings, corresponding to transitional and k-type roughness, and three flow rates, are investigated. Good agreement is observed between the simulation...

intermediate submergence are presented. Scenarios with two bar spacings, corresponding to transitional and k-type roughness, and three flow rates, are investigated. Good agreement is observed between the simulations and the experiments in terms of mean free surface elevations and mean streamwise velocities. Contours of simulated time-averaged strea...

This paper presents large eddy simulations (LESs) of symmetric and asymmetric (cambered) airfoils forced to undergo deep dynamic stall due to a prescribed pitching motion. Experimental data in terms of lift, drag, and moment coefficients are available for the symmetric NACA 0012 airfoil and these are used to validate the LESs. Good agreement betwee...

A numerical simulation of a turbulent round jet issuing into a laminar crossflow is performed using the method of large-eddy simulation (LES). In order to employ LES efficiently for such multi-scale problems, the code utilises a local mesh refinement (LMR) algorithm and employs a multigrid method to solve the incompressible Navier-Stokes equations....

A large-eddy simulation based Eulerian-Lagrangian model is employed to study bubble plumes in an open channel with crossflow. The numerical results are validated with PIV experimental data. Good agreement between simulated and observed velocities is found. The impact of the crossflow on the structure of the plume and the resulting turbulent structu...

In this study a thermal camera was used to inferring the properties of thermal turbulent structures at the water surface of an array of emergent vertical cylindrical obstacles located in staggered fashion at one side of an open channel flow. Three different diameters (D = 1.25 cm, 2.5 cm and 5.0 cm) were tested. A thermal camera SC640 was used to r...

In this paper the effects of boulder concentration on hydrodynamics and local and reach-averaged sediment transport properties with a flow over submerged boulder arrays are investigated. Four numerical simulations are performed in which the boulders' streamwise spacings are varied. Statistics of near-bed velocity, Reynolds shear stresses, and turbu...

Wave breaking plays an important role in wave-structure interaction. A novel control volume finite element method with adaptive unstructured meshes is employed here to study 3-D breaking waves. The numerical framework consists of a “volume of fluid” type method for the interface capturing and adaptive unstructured meshes to improve computational ef...

Characterising the physics involved in the wake developed downstream of vertical axis tidal stream turbines (VATTs) is a cornerstone towards understanding turbine-to-turbine interactions and thus optimise their deployment in arrays. The flow field developed around these devices is not exempt of complexity accentuated by complex blade-vortex interac...

This paper describes a method for the estimation of the time-averaged free surface profile measured directly from particle image velocimetry (PIV) images of a laboratory open channel flow over a transverse square bars of normalized spacings λ/k = 5.2 and λ/k = 10.4 representing transitional and k-type roughness geometries, respectively. Three diffe...

This paper describes a method for the estimation of the time-averaged free surface profile measured directly from particle image velocimetry (PIV) images of a laboratory open channel flow over a transverse square bars of normalized spacings λ/k = 5.2 and λ/k = 10.4 representing transitional and k-type roughness geometries, respectively. Three diffe...