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Journal of Hydrodynamics 2024年第3期36卷 546-555页

作者： wen-bin Zhang wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

Plunging breaking waves play an important role in the exchange of heat,momentum,and mass between the atmosphere and *** this paper,a series of direct numerical simulations is conducted to investigate the fragmentation process of the ingested main cavity in plunging breaking *** two-phase Navier-Stokes equations are solved using the finite-volume method based on adaptive refinement *** free surface is captured using a geometrical volume of fluid *** 2-D,3-D simulations are *** flow fields at different stages of wave breaking are presented and quantitative analysis for bubbles is *** 2-D instantaneous vorticity field and local velocity field are visualized to discuss the general flow characteristics during the fragmentation *** a 2-D parametric study is conducted to investigate the differences in the flow characteristics during the fragmentation process under different wave parameters including initial wave steepness(ε),Bond number(Bo),and Reynolds number(Re).3-D vortex structures are shown to further investigate the mechanisms behind the differences in the flow *** bubble size distributions under two different initial wave steepness are also discussed with their relationship to the fragmentation process of the ingested main *** research offers a significant understanding of the distinct procedures and fundamental dynamics involved in wave breaking,enhancing our comprehension of this intricate event.

关键词： Plunging breaking waves multiphase flow bubble statistics

Numerical analysis of coupled sloshing and motion of a cylindrical FPSO in regular waves

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Journal of Hydrodynamics 2024年第3期36卷 457-465页

作者： wei-wen zhao Xiao-long Yang De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Offshore Oil Engineering Co.Ltd. Tianjin300461China

In this paper,the coupled sloshing and motion characteristics of a cylindrical floating production storage offloading(CFPSO)are numerically investigated by means of computational fluid dynamics(CFD)*** simulations are performed using an in-house CFD solver naoe-FOAM-SJTU which is developed based on *** active wave generating-absorbing boundary condition(GABC)is utilized for wave generation and *** stabilized k-omega SST turbulence model are used to avoid excessive eddy viscosity near the free *** with and without partially filled liquid tanks in regular waves with different wave periods are simulated and vertical planar motions such as surge,heave and pitch response amplitude operators(RAOs)are *** due to liquid sloshing and wave loads are extracted and *** free surface motions inside liquid tanks in one wave period presented to explain the motion characteristics.

关键词： Coupled analysis liquid sloshing wave motion cylindrical floating production storage offloading(CFPSO)

Numerical simulation of liquid sloshing in a spherical tank by MPS method

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Journal of Hydrodynamics 2024年第2期36卷 232-240页

作者： Cong-yi Huang Ji-fei Wang wei-wen zhao De-cheng Wan Computational Marine Hydrodynamic Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Aerospace System Engineering Institute Shanghai201109China

This paper investigates the sloshing phenomena in a spherical liquid tank using the moving particle semi-implicit(MPS)method,a crucial study in fluid *** from previous research focused on rectangular or LNG tanks,this work explores the unique motion patterns inherent to spherical *** accuracy of our in-house MPS solver MLParticle-SJTU is validated against experimental data and finite volume method(FVM).And the MPS method reveals a closer alignment with experimental outcomes,which suggests that MPS method is particularly effective for modeling complex,non-linear fluid *** the fluid’s response to excitation at its natural frequency is simulated,showcasing vigorous sloshing and rotational *** analyses of the fluid motion are conducted by drawing streamline diagrams,velocity vector diagrams,and vorticity *** fluid’s motion response is explored using both time-domain and frequency-domain curves of the fluid centroid,as well as the sloshing force.

关键词： Moving particle semi-implicit(MPS)method spherical tank liquid sloshing model experiment

Numerical investigation of the coupled aero-hydrodynamic performances of a semi-submersible floating offshore wind turbine with inclined columns

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Journal of Hydrodynamics 2024年第2期36卷 316-330页

作者： Ying-jie Xue Xiao-long Yang wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Offshore Oil Engineering Co.Ltd. Tianjin300461China

Numerical investigations of floating platforms with different outer column inclined angles under two operating conditions of regular wave and irregular wave are presented in this paper.A coupled aero-hydrodynamic computational fluid dynamics in-house solver FOWT-UALM-SJTU is applied for the ***,the validation for wave and wind generation are conducted to determine mesh distribution *** on these,the hydrodynamic motion response,aerodynamic performance and wake flow are analyzed to explore the impact of inclined *** spectral analysis on the motion response under wave action,discuss the aerodynamic attack angle and inflow wind velocity along the blade spanwise direction in detail,reveal different trends in wake development and *** results show that for the regular wave condition with the increase of inclined angles,the equilibrium position of surge motion is constantly rising,while pitch is *** maximum root mean square(rms)value occurs at angle=30°,compared with the original OC4 FOWT,the rms in power and thrust increase 0.35%,0.71%.And there are two low regions of attack angle and high regions of axial inflow velocity,corresponding to aerodynamic *** spectral analysis indicates that the natural frequency of pitch motion will increase with inclined ***,from the middle to far region of wake flow,the velocity recovery of FOWT with inclined angle will become faster,which is beneficial for downstream turbines to enhance more wind energy.

关键词： Floating offshore wind turbine numerical simulation aero-hydrodynamic coupled analysis floating platform with inclinedcolumns wake flow recovery

Numerical simulations of multi-layer-liquid sloshing by multiphase MPS method

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Journal of Hydrodynamics 2021年第5期33卷 938-949页

作者： Xiao wen wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In this paper,a multiphase moving particle semi-implicit(MPS)method is developed by introduction of various multiphase models into the original MPS method for single-phase flows,and is then applied to the numerical simulations of two-layer-liquid and three-layer-liquid sloshing in a 2-D rectangular tank under different external *** validate the accuracy of the present multiphase MPS method,the qualitative and quantitative results,including wave profiles,interface elevations and impact pressures,are compared with experimental data and other numerical results,which show a good *** particular,the evolutions of free surface and phase interfaces are compared and an obvious discrepancy is found,indicating that the phase interfaces may suffer from complex deformations while the free surface keeps relatively ***,the different modes of phase interface are observed under different excitation ***,the violent sloshing of a three-layer-liquid system is simulated and the phenomenon of internal wave breaking is well captured,which mainly benefitted from the Lagrangian basis of MPS method and its advantage in multiphase flows with complex ***,the three-layer-liquid sloshing with a vertical baffle are simulated to investigate the suppressing effect of baffle on multi-layer-liquid sloshing.

关键词： Moving particle semi-implicit(MPS) multiphase flows multi-layer-liquid liquid sloshing

Numerical simulations of propeller cavitation flows based on OpenFOAM

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Journal of Hydrodynamics 2020年第6期32卷 1071-1079页

作者： Min-sheng zhao wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

In order to study the cavitation and hydrodynamic characteristics of propeller under uniform and non-uniform flows,numerical investigations are performed using interPhaseChangeDyMFoam in the open source computational fluid dynamics(CFD)software platform OpenFOAM with Schnerr-Sauer cavitation *** simulation results can be used as a reference to evaluate the working ability of a propeller in case of actual navigation.A new grid encryption method is adopted in the research to better capture the existence of vortex cavitation at the propeller *** method of function input is carried out in the study to simulate the condition of non-uniform flow and reduce the calculation *** unsteady dynamics are predicted by the Reynolds-averaged Navier-Stokes(RANS)method with a modified shear stress transport(SST)k−ωturbulence *** numerical results of the propeller such as cavitation shape and pressure distribution under uniform and non-uniform flow are analyzed and compared with each other.

关键词： OpenFOAM E779A propeller cavitation non uniform flow

Numerical investigation on the effects of current headings on vortex induced motions of a semi-submersible

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Journal of Hydrodynamics 2022年第3期34卷 382-394页

作者： wei-wen zhao Zhi-yuan wei De-cheng Wa Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design&Research Institute of China Shanghai200011China Ocean College Zhejiang UniversityZhoushan316021China

In this paper,numerical simulations on vortex-induced motions(VIM)of a semi-submersible at two different current headings are conducted over a wide range of current *** simulations are performed with the computational fluid dynamics(CFD)solver VIM-FOAM-SJTU which is an in-house solver developed based on the OpenFOAM *** turbulent flows are resolved with a shear stress transport-delayed detached eddy simulation(SST-DDES)*** decay tests for transverse and yaw motion are performed in calm still water to make sure the equivalent stiffness is setup *** the results of VIM,including motion response,forces and moments,and flow patterns are presented and analyzed *** including transverse,in-line and yaw motion at different current headings and velocities are *** vorticity in the wake regions at different time stamps are also illustrated for different current headings and velocities.

关键词： Vortex-induced motions(VIM) vortex-induced yaw vim-FOAM-SJTU solver Reynolds stress

Optimization of the roll motion of box-shaped hull section with anti-rolling sloshing tanks and fins in beam waves

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Journal of Hydrodynamics 2021年第4期33卷 688-697页

作者： Xin-wang Liu wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Ocean College Zhejiang UniversityZhoushan316021China

With the development of ocean engineering and demand for safety of the ship and offshore structures, the transportation and storage of liquid have become an important issue nowadays. Furthermore, in order to improve the hydrodynamic performances of the ship and offshore structures, the anti-rolling liquid tanks are often taken into consideration. The internal-external coupling flow effect is vital for the ship and liquid tank designs, especially when the external wave frequency is close to the natural frequency of liquid tanks with a certain filling ratio, large amplitude motions may occur, which is dangerous to some extent. In this paper, the simulation-based-design method is introduced at first, and the verification of the numerical calculation of internal-external coupling flow with liquid tanks is done then. Finally, the filling ratio of the anti-rolling liquid tank and the installation angle of the anti-rolling fins are optimized to reduce the roll motion amplitude of the hull section to the greatest extent under the combined action of the two anti-rolling devices. Optimization results show that the roll motion amplitude of box-shaped hull section can be successfully reduced by reasonably designing the two anti-rolling devices, which can be a reference to the future design of the fishing ship and other ships with anti-rolling devices.

关键词： Tank sloshing anti-rolling fin ship motion in waves ship hydrodynamic optimization

CFD simulations of three-dimensional violent sloshing flows in tanks based on MPS and GPU

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Journal of Hydrodynamics 2020年第4期32卷 672-683页

作者： Feng-ze Xie wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringState Key Laboratory of Ocean EngineeringShanghai Jiao Tong UniversityShanghai 200240China

For violent sloshing,the flow field becomes complicated and 3-D effect is *** addition to the excitation direction,the wave can also propagate perpendicular to the excitation *** to the superposition of waves from different directions,the impact pressure imposed on the wall of the tank may *** this paper,our in-house solver MPSGPU-SJTU based on moving particle semi-implicit(MPS)method coupled with GPU techniques is employed for the liquid sloshing simulation,to study the factors leading to the 3-D ***,a series of sloshing simulations are carried out to validate the reliability of present ***,the sensitivity of 3-D effect against some parameters,such as excitation frequency,dimensions of the tank and filling ratio,is checked through numerical *** histories of pressure obtained by 2-D and 3-D simulations are compared to judge the occurrence of 3-D *** concludes that effects of those parameters are all significant.

关键词： Liquid sloshing 3-D effect sensitive parameters moving particle semi-implicit(MPS)method MPSGPU-SJTU solver

Numerical simulations of sloshing waves in vertically excited square tank by improved MPS method

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Journal of Hydrodynamics 2022年第1期34卷 76-84页

作者： Guan-yu Zhang wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

Faraday wave is a phenomenon of sloshing due to a heave motion of a partially filled tank,which is also called parametric instability or parametric *** the present paper,the phenomenon of faraday wave in a pure heave excited square tank is numerically simulated through the moving particle semi-implicit(MPS)*** surface tension effect and a new Dirichlet boundary condition for the pressure Poisson equation are considered to avert unphysical fragmentation and clustering of particles in splash *** the numerical simulation,the evolution of wave motion,and the non-linearity together with breaking phenomenon of faraday wave can be *** agreement is good in general,both amplitude and ***,the parameter studies including the excitation frequency and the forcing amplitude are carried out to analyses the mechanism of resonances response.

关键词： Liquid sloshing faraday wave moving particle semi-implicit(MPS)method surface tension MLParticle-SJTU solver