In the published article [1] there is an error in the listing of the last author. “Dahlhaug G. Ole” should be “Ole Gunnar Dahlhaug” as listed in this erratum.

In order to study the effects of the confining pressure on the erosion characteristics of the self-resonating cavitating jet under wellbore and deep-water conditions, experiments are conducted on aluminum specimens impinged by the organ pipe cavitation nozzle and the conical nozzle with the confining pressure in the range 0 MPa–10.0 MPa. Meanwhile, through the numerical simulation of the collapsing

In this paper, an artificial neural network (ANN) trained through a deep reinforcement learning (DRL) agent is used to perform flow control. The target is to look for the wake stabilization mechanism in an active way. The flow past a 2-D cylinder with a Reynolds number 240 is addressed with and without a control strategy. The control strategy is based on using two small rotating cylinders which are

To solve the problem of inaccurate boundary identification and to eliminate the spurious pressure oscillation in the previously developed immersed smoothed point interpolation method (IS-PIM), a new sharp-interface IS-PIM combining mass conservation algorithm, called Sharp-ISPIM-Mass, is proposed in this work. Based on the so called sharp-interface method, the technique of quadratic local velocity

In-depth analyses of existing direct numerical simulations (DNS) data led to a logical and important classification of generic turbulent boundary layers (TBLs), namely Type-A, -B and -C TBL, based on the distribution patterns of the time-averaged wall-shear stress. Among these types, Type-A TBL and its related law formulations were investigated in terms of the analytical velocity profiles independent

In recent years, artificial neural networks (ANNs) and deep learning have become increasingly popular across a wide range of scientific and technical fields, including fluid mechanics. While it will take time to fully grasp the potentialities as well as the limitations of these methods, evidence is starting to accumulate that point to their potential in helping solve problems for which no theoretically

Nowadays the rapidly developing artificial intelligence has become a key solution for problems of diverse disciplines, especially those involving big data. Successes in these areas also attract researchers from the community of fluid mechanics, especially in the field of active flow control (AFC). This article surveys recent successful applications of machine learning in AFC, highlights general ideas

The analytical method was adopted to investigate the earthquake-induced hydrodynamic pressure on a circular cylinder surrounded by two-layer fluid. Based on the radiation theory, the analytical expressions of hydrodynamic pressure, hydrodynamic force on a rigid circular cylinder were obtained. Then, the dispersion relation for radiation problem in a two-layer fluid, and the added mass and damping coefficients

In this paper, several commonly used vortex identification methods for marine hydrodynamics are revisited. In order to extract and analyse the vortical structures in marine hydrodynamics, the Q, λ2 - criterion and modified normalized Liutex/Rortex Ω͂R method are utilized for vortex identification for propeller open water test, ship drag test, ship propeller-rudder interaction, VIV of a marine riser

In combination with a channel bed, suspended vegetationin an open channel can alter flow structure and generate vertically asymmetric flow. This study investigated the mean flow and turbulence structure of an open channel with suspended vegetation through theoretical analysis and laboratory experiments. Three patterns of bionic leaves with different roughness were adopted to imitate suspended vegetation

Most hydrodynamic problems in ship and ocean engineering are complex and highly coupled. Under the trend of intelligent and digital design for ships and ocean engineering structures, comprehensive performance evaluation and optimization are of vital importance during design. In this process, various coupling effects need to be accurately predicted. With the significant progress of computational fluid

The third-generation vortex identification method of Liutex (previously called Rortex) was introduced by the team led by Prof. Chaoqun Liu from University of Texas at Arlington to mathematically extract the rigid rotation part from the fluid motion, and thus to define and visualize vortices. Unlike the vorticity-based first generation and the scalar-valued second generation, Q, λ2, Δ and λci methods

An unstructured mesh Reynolds-averaged Navier-Stokes (RANS) solver has been developed for numerical simulation of violent sloshing flows inside a tank with complicated inner structures. The numerical solver employs the unstructured multi-dimensional tangent hyperbolic interface capturing method (UMTHINC) for free-surface capturing combined with various turbulence models. The sloshing motion is numerically

The wave parameters (the wave height and period) are important environmental factors in the ocean engineering design. General numerical wave models, such as SWAN and WAVEWATCH, are widely employed to simulate the wave conditions. However, significant differences were observed between the measurement and the simulation for both the wave height and period, which asks for wave model improvements. The

In the present work, a 3-D aerator device with backward lateral deflectors, called BLD-3-D aerator device, is developed, and the lateral cavity and fin performance of the BLD-3-D aerator device are experimentally investigated. The findings show that, the relative lateral cavity length with backward lateral deflectors is shorter than that with current lateral deflectors under the same approach flow

In order to manipulate large-scale coherent structures in the wall-bounded turbulence and reduce the skin-friction, an active-control experimental investigation was performed through synchronous and asynchronous vibrations of double piezoelectric vibrators embedded spanwisely on a smooth flat plate surface. A TSI-IFA300 hot-wire anemometer and TSI-1621A-T1.5 hot-wire probe were used to measure the

Nonlinear steady-state waves are obtained by the amplitude-based Homotopy Analysis Method (AHAM) when resonances among surface gravity waves are considered in water of finite depth. AHAM, newly proposed in this paper within the context of Homotopy Analysis Method (HAM) and well validated in various ways, is able to deal with nonlinear wave interactions. In waves with small propagation angles, it is

The added resistance of a ship in waves can be related to ship-generated unsteady waves. In the present study, the unsteady wave-pattern analysis is applied to calculate the added resistance in waves for two modified Wigley models using a Cartesian-grid method. In the present numerical method, a first-order fractional-step method is applied to the velocity-pressure coupling in the fluid domain, and

In the present work, a slot-type flip bucket with separated flows, called SFS-type flip bucket, is developed, and flow regime and energy dissipation are experimentally investigated. Comparing with the circular-shaped or slot-type flip bucket buckets, the present SFS-type flip bucket has better flow regime and larger energy dissipation since the three branches of the flows are separated through the

We present a numerical simulation of the so-called condensation shock on a NACA0015 hydrofoil with a finite mass transfer model for the first time. Most recently, condensation shock was indentified in the experimental measurement as a mechanism for partial cavity shedding in the flow past a hydrofoil. Compressible solvers, which were adopted in the previous simulations to study such phenomenon numerically

In this paper, the transient turbulent cavitating flow around a marine propeller behind a ship was investigated experimentally with emphasis on how vortex generator (VG) influences propeller cavitation and hull pressure fluctuations. The experiments were carried out in China Large Cavitation Channel with the closed test section covering 10.5 m in length and cross-section of 2.2 m2 ϗ 2.0 m2. The experiment

One of the critical issues in numerical simulation of fluid-structure interaction problems is inaccuracy of the solutions, especially for flows past a stationary thin elastic structure where large deformations occur. High resolution is required to capture the flow characteristics near the fluid-structure interface to enhance accuracy of the solutions within proximity of the thin deformable body. Hence

In this study, the effect of the free surface on the supercavitating flow that surrounds a low aspect ratio wedge-shaped hydrofoil is studied based on computational fluid dynamics (CFD), with Cartesian cut-cell mesh method. The volume of fraction (VOF) method and the k - ε turbulence model with the Schnerr Sauer cavitation model are used for simulating the supercavitation in turbulent flow. Both quasi-3-D

The hydrodynamics and flow structures of a base wing slotted with tip sails in proximity to the ground were studied experimentally in order to investigate the flow control efficiency of wing tip sails in ground effect. The experiment was conducted in a towing tank at a Reynolds number 1.5×105. The lift and drag forces were measured by a transducer, the velocity fields of the wing tip vortices were

Cavitating bubbly flows can form in separated flows and shear layers leading to local regions high vapor void fraction, and these flows often exhibit periodic shedding of vaporous clouds. Historically, the presence of a liquid re-entrant flow, driven by the kinematics of liquid flow stagnation, has been identified as an important mechanism leading to cavity shedding. However, high local vapor void

In the present paper, the turbulent cavitating flow generated by a Clark-Y hydrofoil is investigated by large eddy simulation (LES) combined with Zwart-Gerber-Belamri (ZGB) cavitation model. In order to shed light on the influence of cavitation on turbulent energy distribution among scales, energy spectrum obtained from the three-dimensional velocity field is firstly applied to turbulent cavitating

To study the serious valve top gap cavitation of Datengxia high head single-lift ship lock, the 1:1 scale slice experiment is carried out, to truly reveal the gap flow characteristics, as well as the valve top gap cavitation characteristics and the anti-cavitation mechanism of natural aeration. Three kinds of cavitation, namely, the throat cavitation, the mainstream inner cavitation, and the valve

This paper presents an analytical model to solve the linear wave diffraction problem by arrays of bottom-mounted cylinders with arbitrary smooth cross-section. Based on the assumption of ideal fluid and potential theory, the unknown coefficients of total velocity potential can be solved by system of linear equations, which are obtained from the boundary conditions. The accuracy of the present method

The hydrodynamics in a straight open channel with a multiple-embayment groyne field was investigated using the detached-eddy simulation (DES). A series of short groynes were included on a 1:3 side slope of the channel. This work focuses on the turbulent coherent structures around groynes on an uneven bottom. Flows around groyne fields are characterized by massive separation and highly unsteady vortices

The wave transformation over slope topography is widely studied, but most of studies are for common coastal slopes. This paper presents an experimental study of 2-D regular and irregular wave transformations on a simplified coral reef with a steep slope of 1:5 and a horizontal reef flat, focusing on the characteristics of the waves that break on the reef flat. The analyzed results show that the estimates

Cavitating flows are dominated by large gradients of physical properties and quantities containing complicated interfacial structures and lots of multi-scale eddies that need to be accurately characterized using a high-resolution mesh. The present work, within OpenFOAM, proposes an effective modeling framework using the large eddy simulation (LES) approach along with the volume of fluid (VOF) method

This paper studies the unsteady three-dimensional cavitating turbulent flow in a jet pump. Specifically, thefocus is on the unstable limited operation stage, and both the computational and experimental methods are used. In the experiments, the distribution of the wall pressure, as well as the evolution of cavitation over time, are obtained for a jet pump. Computation is carried out using the large

A reliable numerical tool for the prediction of the parametric roll is important in the development of the second generation intact stability criteria. The main difficulty of the prediction of the parametric roll comes from the significant coupling of the roll with other motions, especially the heave and pitch motions. In this paper, the numerical method for determining the parametric roll is studied