The vortex-induced vibration (VIV) suppression of a circular cylinder with the axial-slats is numerically investigated using the computational fluid dynamics (CFD) method for Reynolds number range of 8.0 × 103–5.6 × 104. The two-dim...
As one of the typical negative factors affecting the vortex structure and flow characteristics of hydraulic machinery, the TLV has a non-negligible impact on the energy performance. In order to improve the utilization efficiency of hydraulic machiner...
The stability of axial flow pumps is significantly affected by the tip leakage vortex (TLV), which is generated through the entrainment of the main flow. This study explores the effects of circumferential grooving in the rotor chamber on the tip leak...
Cylindrical structures are widely used in offshore and marine engineering, but they may suffer from vortex-induced vibration under the influence of ocean or wave currents, which can lead to severe fatigue damage. In this study, we applied the open-so...
Long-span steel box girder suspension bridges are prone to vortex-induced vibrations (VIVs) due to their light weight, flexible characteristics, and low structural damping. Traditional temporary aerodynamic measures, although effective in vibration s...
Hydro energy is a kind of typical renewable energy, which can be converted by hydraulic machinery. However, tip leakage vortex (TLV) has a significant negative influence on the flow pattern and energy performance of hydraulic machinery. In this paper...
In this paper, an experimental study is conducted to investigate the effectiveness of vibration dampers in suppressing vortex-induced vibration in a long, flexible catenary cable with a low mass ratio. The dampers, consisting of two small, symmetric,...
Vortex shedding phenomenon behind bluff bodies and its destructive unsteady wake can be controlled by employing active and passive flow control methods. In this quest, researchers employed experimental fluid dynamics (EFD), computational fluid dynami...
The hydrodynamic noise from the horseshoe vortex can greatly destroy the acoustic stealth of underwater vehicles at low frequency. We investigated the flow-induced noise suppression mechanism by mechanical vortex generators (VGs) on a SUBOFF model. B...
Interaction of recirculating and mean flow downstream of a submerged gate may form significant vortex structures, which may affect the stability of the gate. Although these flow structures that appear in submerged hydraulic jumps received considerabl...
The vortex rope in the draft tube is considered as the major contributor to pressure pulsation at partial load (PL) conditions, which causes the hydro unit to operate unstably. Based on the prototype Francis turbine HLA551-LJ-43 in the laboratory, J-...
Under partial load operating conditions, vortex rope generation in the draft tube of a Francis turbine is considered one of the main reasons for hydro unit vibration. In this paper, a Francis turbine HLA551-LJ-43 in the laboratory was taken as a prot...
Francis turbines are most widely used in hydropower due to their characteristics which include a fast response and wide time-scale operation. The vortex rope inside Francis turbines is a common flow phenomenon, which always causes strong vibration, p...
Harbor seals (Phoca vitulina) have excellent perception of water disturbances and can still sense targets as far as 180 m away, even when they lose their vision and hearing. This exceptional capability is attributed to the undulating structure of its...
To investigate the suppression method for vortex-induced vibrations (VIV) of two-degree-of-freedom (2-DOF) rotating cylinders with dual splitter plates, numerical simulations are conducted at a Reynolds number of 200, a mass ratio of 2.6, and rotatio...
This paper carried out wind tunnel tests and numerical analysis to study the effect of the spatial position of deflector plates on the vortex-induced vibration (VIV) of a double-deck truss girder. The wind tunnel tests found that setting the web defl...
The effect of triple helical grooves on the suppression of vortex-induced vibration (VIV) of a circular cylinder was investigated experimentally in a wind tunnel over Reynolds number in the range of 1 × 104 < Re < 4 × 104. It was fo...
Corner separation at the junction of blade surfaces and end walls remains a significant challenge in compressor cascade performance. This study proposes a passive flow control strategy inspired by the geometric arrangement of biological fish scales t...
Conventional firefighting tools and methods can strain water sources, require toxic foams, or rely on pre-installed countermeasures. A low-cost, non-toxic, and portable option was previously overlooked in portable devices: electrically assisted &ldqu...
With the expansion of offshore oil and gas resources to deepwater areas, the problem of the vortex-induced vibration of marine risers, as a key structure connecting offshore platforms and subsea wellheads, has become increasingly prominent. At presen...
Improving energy efficiency and thermal management in enclosure-based systems requires an understanding of how internal geometry governs buoyancy-driven flow and heat transfer. This study employs a partition-based control strategy to regulate flow or...
The aim of this paper is to investigate the vibration suppression effect of a nonlinear energy sink (NES) on the wind-vortex-induced vibration of deep-water jacket pipes. Based on nonlinear dynamical theories, the coupled dynamic equation of a deep-w...
Some very useful methods for suppressing the flow-induced vibration (FIV) of a single cylinder are known to potentially have a limited efficiency for tandem-arrangement cylinders. In this paper, three splitter plates uniformly attached around a cylin...
Numerical simulations are carried out to investigate the vortex-induced vibrations of a two-degree-of-freedom (2DOF) near-wall rotating cylinder. Considering the effects of gap ratio, reduced velocity and rotational rate, the amplitude response, wake...
The influencing characteristic for the evolution mechanism of a dynamic stall vortex structure and distributed blowing control on rotor airfoils was investigated. Based on the moving-embedded grid method, the finite volume scheme, and Roe’s FDS...
The upgrade of Akkats power station in Sweden included a new, separate waterway for the addition of a 75 MW generating unit. The vertical intake of its headrace was formed by means of lake tapping. A physical model was used to help understand the bla...
High hydrodynamic noise is a threat to the survival of underwater vehicles. We investigated a noise suppression mechanism by putting leading-edge serrations on the sail hull of a scaled SUBOFF model, through numerical calculation and an experimental...
A discrete vortex method is implemented with a hybrid control technique of vortex shedding to solve the problem of the two-dimensional flow past a slightly rough circular cylinder in the vicinity of a moving wall. In the present approach, the passive...
Single-crystal iron oxide nanorings have been proposed as a promising candidate for magnetic hyperthermia application because of their unique shape-induced vortex-domain structure, which supports good colloidal stability and enhanced magnetic propert...
The bowl diffuser is the main flow component in multistage submersible pumps; however, secondary flow fields can easily induce a separation vortex in the hub corner region of the bowl diffuser during normal operation. To explore the flow mechanism of...
The energy-conversion stability of hydropower is critical to satisfy the growing demand for electricity. In low-head hydropower plants, a gravitational surface vortex is easily generated, which causes irregular shock vibrations that damage turbine pe...
A common challenge faced by engineers in the hydraulic industry is the formation of free surface vortices at pump and power intakes. This undesirable phenomenon which sometimes entrains air could result in several operational problems: noise, vibrati...
This study aims to demonstrate the merits of pressure-relieving holes at the tip region of propellers, which is introduced as “PressurePoresTM” technology as a retrofit on marine propellers to mitigate tip vortex cavitation noise for a qu...
Guideway hydrostatic bearings with the function of supporting and moving loads are a key component of ultra-precision heavy-duty machine tools. Because the dimension difference between the oil gap and the overall structure is great, it is difficult t...
The long-span double-deck truss girder bridge has become a recommend structural form because of its good performance on traffic capacity. However, the vortex-induced vibration (VIV) characteristics for double-deck truss girders are more complicated a...
Hub corner is a high-loss area located within in the blade passages of turbomachinery. It is well known that flow separation and vortex development in this area directly affects, not only energy loss and efficiency, but also the stability of axial co...
Vortex beams with orthogonality can be widely used in atmospheric applications. We numerically analyzed the statistical regularities of vortex beams propagating through a lens or an axicon with different series of turbulent air phase screens. The sim...
The magnetic field
Undesirable flow phenomena in Francis turbines are caused by pressure fluctuations induced under conditions of low flow rate; the resulting vortex ropes with precession in the draft tube (DT) can degrade performance and increase the instability of tu...
Under low flow-rate conditions, a Francis turbine exhibits precession of a vortex rope with pressure fluctuations in the draft tube. These undesirable flow phenomena can lead to deterioration of the turbine performance as manifested by torque and pow...
A long-span double-deck steel truss suspension bridge is easy to produce vortex-induced vibration (VIV) at low air velocity, which affects bridge service life. Additional aerodynamic measures play a role in suppressing VIV by changing the aerodynamic...
Laminar-to-turbulent transition in a swept flat-plate boundary layer is caused by the breakdown of the crossflow vortex via high-frequency secondary instability and is promoted by the wall-surface roughness and the freestream turbulence (FST). Althou...
This study conducted numerical simulations of three-dimensional vortex-induced vibrations (VIV) on cylindrical bodies with various surface protrusion coverage rates, systematically investigating the impact of coverage and protrusion height on the vib...
The ducted coaxial propeller (DCP) has great application value in eVTOL aircraft because of its high safety, compactness, and low noise. A numerical simulation method for the DCP is established using the sliding mesh technique. A DCP was designed and...
A harbor seal’s whisker is able to sense the trailing vortices of marine organisms due to its unique three-dimensional wavy shape, which suppresses the vibrations caused by its own vortex-shedding, while exciting large-amplitude and synchronize...
This study aimed to determine the flow structures and heat transfer for flow past a tandem cylinder array and the effect of a slit on the enhancement of heat transfer. Different distances between cylinders and inclination angles of the slit were simu...
In this paper, the two-dimensional Kelvin–Helmholtz (KH) instability occurring in the shear flow of polymer fluids is modeled by the dissipative particle dynamics (DPD) method at the coarse-grained molecular level. A revised FENE model is propo...
The occurrence of low-frequency instability (LFI) appears to be related to multiple interactions among many complex physical processes, such as vortex shedding, boundary-layer oscillation, and additional combustion in the post-combustion chamber. In...
The slots on a blade tip can effectively suppress the tip vortices by diffusing the core structure of a vortex and thus mitigate the adverse impacts of vortex interactions. In this paper, the effect of a slotted tip on vortex diffusion in the hoverin...
Large-span suspension bridges are susceptible to wind loads. Therefore, a more precise analysis of their wind-induced vibration response is necessary to ensure the structure’s absolute safety. This investigation conducted wind tunnel tests for...
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