Numerical Analysis of the Turbulent Flow Structure Induced by the Cavitation Shedding using LES

Kanfoudi, Hatem; Bellakhal, Ghazi; Ennouri, Marwa; Taher, Ahmed; Zgoll, R.

doi:10.18869/acadpub.jafm.73.240.27384

Cited by 6 publications

(5 citation statements)

References 68 publications

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“…We notice that the results which correspond to the meshes M1 and M2 are nearly similar. Therefore, we adopt the mediumresolution mesh for the unsteady cavitation simulation, which is based on the study of Kanfoudi et al (2017).…”

Section: Fig 2 Naca009 3d Geometrymentioning

confidence: 99%

Numerical Prediction Approach of Cavitation Erosion based on 3D Simulation Flow

2022

JAFM

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In industry, the phenomenon of cavitation erosion can reduce the lifetime of the components of hydraulic machines. In this article, we present a new numerical approach to predict the mechanical impact resulting from the implosion of a cloud of bubbles, based on an energy approach. The objective of this approach is to determine the main damage mechanisms and to estimate the intensity of the impact pressure near the surface. The large eddy simulation (LES) approach is coupled with a homogeneous cavitation model to assess the risk of erosion around the hydrofoil NACA0009. Indeed, three functions, namely the Pressure Intensity Function (PIF), the steam intensity function and the Erosive Power Function (EPF), are applied to assess the spatial distribution of eroded areas. The calculations show that the functions based on the pressure term are in good agreement with the experiments, namely: the PIF and EPF functions. On the other hand, we assume that the implosion of the cloud of bubbles produces a pressure wave, which in turn causes the implosion of small bubbles near the wall. Then the erosion will be the result of these secondary implosions and not of the cloud of bubbles. Therefore, we vary the degree of proximity of these micro-bubbles near the wall to choose either the shock wave or the micro-jet to extrapolate the pressure field. We can compare these estimates with the existing erosion measurements and we can conclude that the calculations respond more to the probability of the presence of a micro-jet than to the presence of a shock wave.

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Section: Fig 2 Naca009 3d Geometrymentioning

confidence: 99%

Numerical Prediction Approach of Cavitation Erosion based on 3D Simulation Flow

2022

JAFM

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“…Gunnarson et al (2019) examined the pitching hydrofoil for five different linear models to predict a minor lateral alteration made by a hydrofoil undergoing biased pitch oscillations. The interaction between the vortex pattern and the cavitation shedding dynamics was modeled by large eddy simulation (Kanfoudi et al 2017). There are many genus in the ocean that can serve as engineering inspiration and the humpback whale is one such species (Utama et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Various Wavy Leading-Edge Protuberance on Oscillating Hydrofoil Power Performance

2023

JAFM

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This paper is presented to compare various wavy leading-edge protuberances on oscillating hydrofoil performance and power efficiency. The unsteady turbulent 3D flow simulations were carried out by using the StarCCM+ software. The 3D hydrofoil with a straight at the leading-edge is a NACA0015 section with a chord of 0.24 m and an aspect ratio of 7. Four new types of hydrofoils are proposed with wavy leading-edge protuberance. The RANS equations with the realizable k–ε turbulence model are used to predict the turbulent flow around the hydrofoil under different conditions. In order to validate, a comparison of the numerical results of the forces coefficients and power efficiency of non-protuberance oscillating hydrofoil are shown in good agreement with experimental data. Then, four new profiles on the leading-edge of the hydrofoils are simulated and many results of the pressure distribution, vorticity contour, streamline velocity, and power coefficient for five hydrofoil types are presented and discussed. It is concluded that the hydrofoil of Type-M can achieve constantly higher efficiency of over 46% by employing appropriate heave and pitch amplitudes.

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“…Two orientations of a smooth heating tube, horizontal and vertical, were used in the boiling chamber. For their part, Kanfoudi et al [24] employed the large eddy simulation (LES) to perform a numerical analysis of the turbulent flow structure induced by the cavitation shedding. In addition, Djeddi et al [25] conducted a simulation of a viscous fluid flow over an unconventional diamond-shaped obstacle inside a confined channel, for low to moderate Reynolds numbers.…”

Section: Introductionmentioning

confidence: 99%

Turbulent Flow Around Obstacles: Simulation and Study with Variable Roughness

Yousfi¹,

Aliane²

2021

IJHT

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The present work aims to investigate the recirculation and incipient mixing zones in a channel flow supplied with obstacles. The main objective is to develop a new technique to control these recirculation zones by setting a variable roughness. For the purpose of varying that roughness, 4 small bars of heights 0.25H, 0.5H, 0.75H and H were placed downstream of the obstacle; H is the height of the obstacle. For this, a three-dimensional numerical approach was carried out using the ANSYS CFX computer code. In addition, the governing equations were solved using the finite volume method. The K-ω shear-stress transport (SST) turbulence model was utilized to model the turbulent stresses. In the end, we presented the time-averaged simulation results of the contours of the current lines (3D time-averaged streamlines, trace-lines), three components of the velocities: <u> (velocity u contour), <v> (velocity v contour) and <w> (velocity w contour), trace-lines, stream ribbons and mean Q-criterion iso-surface.

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Numerical Analysis of the Turbulent Flow Structure Induced by the Cavitation Shedding using LES

Cited by 6 publications

References 68 publications

Numerical Prediction Approach of Cavitation Erosion based on 3D Simulation Flow

Numerical Prediction Approach of Cavitation Erosion based on 3D Simulation Flow

Various Wavy Leading-Edge Protuberance on Oscillating Hydrofoil Power Performance

Turbulent Flow Around Obstacles: Simulation and Study with Variable Roughness

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