Influence of the hydrofoil trailing-edge shape on the temporal-spatial features of vortex shedding

Lu, Zhaoheng; Zhang, Fangfang; Jin, Faye; Xiao, Ruofu; Tao, Ran

doi:10.1016/j.oceaneng.2022.110645

Cited by 9 publications

(4 citation statements)

References 44 publications

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“…When fluid flows over a smooth TE, vortices tend to form at the edge due to the pressure difference between the upper and lower surfaces of the airfoil [206,207]. These vortices can create tonal noise as they shed and interact with the downstream flow [208].…”

Section: Trailing Edge Treatmentsmentioning

confidence: 99%

Recent Advances in Airfoil Self-Noise Passive Reduction

Amirsalari,

Rocha

2023

Aerospace

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Airflow-induced noise prediction and reduction is one of the priorities for both the energy and aviation industries. This review paper provides valuable insights into flow-induced noise computation, prediction, and optimization methods with state-of-the-art efforts in passive noise reduction on airfoils, blades, and wings. This review covers the combination of several approaches in this field, including analytical, numerical, empirical, semi-empirical, artificial intelligence, and optimization methods. Under passive noise reduction techniques, leading and trailing edge treatments, porous materials, controlled diffusion airfoils, morphing wings, surface treatments, and other unique geometries that researchers developed are among the design modification methods discussed here. This work highlights the benefits of incorporating multiple techniques to achieve the best results concerning the desired application and design. In addition, this work provides an overview of the advantages and disadvantages of each tool, with a particular emphasis on the possible challenges when implementing them. The methods and techniques discussed herein will help increase the acoustic efficiency of aerial structures, making them a beneficial resource for researchers, engineers, and other professionals working in aviation noise reduction.

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Section: Trailing Edge Treatmentsmentioning

confidence: 99%

Recent Advances in Airfoil Self-Noise Passive Reduction

Amirsalari,

Rocha

2023

Aerospace

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“…The SST k-ω model takes into account the transfer of turbulence shear stress and can accurately predict the flow initiation and separation under negative pressure gradients. It also exhibits high accuracy in simulating free shear turbulence, attached boundary layer turbulence, and moderate separation turbulence [29]. Compared to other turbulence models, it not only enhances the functionality of wall modeling but also avoids excessive mesh refinement near the walls, which could lead to the sensitivity of the solution to the wall grid.…”

Section: Numerical Setup and Boundary Conditionsmentioning

confidence: 99%

Hydraulic Characterization of Variable-Speed Pump Turbine under Typical Pumping Modes

Shang,

Cao,

Wang

et al. 2023

Processes

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The pump turbine is a crucial component of pumped storage hydropower plants. When operated at a constant speed, it does not respond well to variations in the grid frequency. To improve the hydraulic efficiency of pumped storage units, variable-speed units have been introduced. However, the mechanism of variable-speed pump turbines has not been extensively studied numerically. In this study, the flow characteristics of a variable-speed pump turbine were computed under two typical pumping modes, the maximum head and minimum flow rate condition, as well as the minimum head and maximum flow rate condition. The computed results aligned with experimental results, and the changing trends of hydraulic thrust under these two pumping modes were discussed. The error for the Hmax, Qmin condition was 1.3%, and the error for the Hmin, Qmax condition was −1.9%. These error values fell within a reasonable range. The research findings indicate that in the Hmax, Qmin condition, the flow within the flow passage exhibited higher velocity, which was 84.87 m/s, increased flow turbulence, larger pressure fluctuations, and poorer unit stability. On the other hand, in the Hmin, Qmax condition, both the axial hydraulic thrust and radial forces were greater, and there were sudden changes in the extreme values of pressure fluctuations over a certain period of time. It is recommended to avoid operating the variable-speed pump turbine under these two conditions during pumping operations.

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“…Due to the changes in the flow rate during the operation of the Yellow River long-distance water transportation pipelines, different degrees of sand deposition are produced in the pipelines. The characteristics of sand transport in the pipe can be described by the flow regime, which is divided into different velocities [2][3][4][5][6][7]. With a sufficiently high flow velocity, the sand can be completely suspended in the water, which can be considered as a homogeneous flow.…”

Section: Introductionmentioning

confidence: 99%

Study on Critical Velocity of Sand Transport in V-Inclined Pipe Based on Numerical Simulation

Yao

Zeng

et al. 2022

Water

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The Yellow River has a high sand content, and sand deposition in the pipelines behind the pumping station occurs from time to time. It is of great significance to reasonably predict the critical velocity of the small-angled V-inclined water transportation pipes. In this study, a Eulerian multiphase model was employed to simulate the solid–liquid two-phase flow. Based on the conservation of the sand transport rate, the critical velocity of the V-inclined pipe was predicted. The effects of simulated pipeline length, pipe inclination and particle size were investigated. The results show that when the simulated pipeline length reached a certain value, it did not affect the prediction of the critical velocity of the overall pipeline. The ±2∘ pipe inclination had a negligible effect on the critical velocity for transporting small-sized particles, but it led to the nonuniform and asymmetrical distribution of liquid velocity and sand deposition at the different cross-sections. As the particle size increased, the critical velocity also increased. However, the influence of particle size on the critical velocity is currently complicated, resulting in a large difference between numerical simulation and empirical formulas when transporting large-sized particles. Accurate prediction of critical velocity is important for long-distance water transportation pipelines to prevent sand deposition and reduce costs.

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Influence of the hydrofoil trailing-edge shape on the temporal-spatial features of vortex shedding

Cited by 9 publications

References 44 publications

Recent Advances in Airfoil Self-Noise Passive Reduction

Recent Advances in Airfoil Self-Noise Passive Reduction

Hydraulic Characterization of Variable-Speed Pump Turbine under Typical Pumping Modes

Study on Critical Velocity of Sand Transport in V-Inclined Pipe Based on Numerical Simulation

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