scholarly journals Numerical Simulation of the Vortex Shedding Behind an Airfoil-Spoiler Configuration

2018 ◽  
Vol 5 (1) ◽  
pp. 16
Author(s):  
Amr Guaily
Keyword(s):  
Numerical Simulation ◽  
Vortex Shedding

Numerical Simulation of Vortex Shedding From a Circular Cylinder in the Presence of a Free Surface

2003 ◽  
Author(s):  
S. Nagaya ◽  
R. E. Baddour
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Free Surface ◽  
Circular Cylinder ◽  
Vortex Shedding ◽  
Fluid Flows ◽  
Reynolds Numbers ◽  
Cfd Simulations ◽  
Induced Drag

CFD simulations of crossflows around a 2-D circular cylinder and the resulting vortex shedding from the cylinder are conducted in the present study. The capability of the CFD solver for vortex shedding simulation from a circular cylinder is validated in terms of the induced drag and lifting forces and associated Strouhal numbers computations. The validations are done for uniform horizontal fluid flows at various Reynolds numbers in the range 103 to 5×105. Crossflows around the circular cylinder beneath a free surface are also simulated in order to investigate the characteristics of the interaction between vortex shedding and a free surface at Reynolds number 5×105. The influence of the presence of the free surface on the vortex shedding due to the cylinder is discussed.

Numerical Simulation of Vortex Shedding Past a Circular Cylinder in a Cross-Flow at Low Reynolds Number With Finite Volume-Technique: Part 1 — Forced Oscillations

2007 ◽  
Author(s):  
Antoine Placzek ◽  
Jean-Franc¸ois Sigrist ◽  
Aziz Hamdouni
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Circular Cylinder ◽  
Finite Volume ◽  
Vortex Shedding ◽  
Stokes Equations ◽  
Cross Flow ◽  
Forced Oscillations ◽  
Lift And Drag ◽  
Wake Characteristics

The numerical simulation of the flow past a circular cylinder forced to oscillate transversely to the incident stream is presented here for a fixed Reynolds number equal to 100. The 2D Navier-Stokes equations are solved with a classical Finite Volume Method with an industrial CFD code which has been coupled with a user subroutine to obtain an explicit staggered procedure providing the cylinder displacement. A preliminary work is conducted in order to check the computation of the wake characteristics for Reynolds numbers smaller than 150. The Strouhal frequency fS, the lift and drag coefficients CL and CD are thus controlled among other parameters. The simulations are then performed with forced oscillations f0 for different frequency rations F = f0/fS in [0.50–1.50] and an amplitude A varying between 0.25 and 1.25. The wake characteristics are analysed using the time series of the fluctuating aerodynamic coefficients and their FFT. The frequency content is then linked to the shape of the phase portrait and to the vortex shedding mode. By choosing interesting couples (A,F), different vortex shedding modes have been observed, which are similar to those of the Williamson-Roshko map.

Vortex Shedding by LES 3D Numerical Simulation

2017 ◽  
Author(s):  
Marcela Lima Santos ◽  
Michèle Schubert Pfeil ◽  
Alvaro Luiz Gayoso de Azeredo Coutinho
Keyword(s):  
Numerical Simulation ◽  
Vortex Shedding ◽  
3D Numerical Simulation

A Numerical Simulation of Vortex Induced Vibration on a Elastically Supported Circular Rigid Cylinder at Moderate Reynolds Numbers

2008 ◽  
Author(s):  
Jean-Franc¸ois Sigrist ◽  
Cyrille Allery ◽  
Claudine Beghein
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Circular Cylinder ◽  
Finite Volume ◽  
Vortex Shedding ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Forced Oscillations ◽  
Vortex Induced Vibration ◽  
Elastically Supported

The present paper is the sequel of a previously published study which is concerned with the numerical simulation of vortex-induced-vibration (VIV) on an elastically supported rigid circular cylinder in a fluid cross-flow (A. Placzek, J.F. Sigrist, A. Hamdouni; Numerical Simulation of Vortex Shedding Past a Circular Cylinder at Low Reynolds Number with Finite Volume Technique. Part I: Forced Oscillations, Part II: Flow Induced Vibrations; Pressure Vessel and Piping, San Antonio, 22–26 July 2007). Such a problem has been thoroughly studied over the past years, both from the experimental and numerical points of view, because of its theoretical and practical interest in the understanding on flow-induced vibration problems. In this context, the present paper aims at exposing a numerical study based on a fully coupled fluid-structure simulation. The numerical technique is based on a finite volume discretisation of the fluid flow equations together with i) a re-meshing algorithm to account for the cylinder motion ii) a projection subroutine to compute the forces induced by the fluid on the cylinder and iii) a coupling procedure to describe the energy exchanges between the fluid flow and solid motion. The study is restricted to moderate Reynolds numbers (Re∼2.000–10.000) and is performed with an industrial CFD code. Numerical results are compared with existing literature on the subject, both in terms of cylinder amplitude motion and fluid vortex shedding modes. Ongoing numerical studies with different numerical techniques, such as ROM (Reduced Order Models)-based methods, will complete the approach and will be published in next PVP conference. These numerical simulations are proposed for code validation purposes prior to industrial applications in tube bundle configuration.

Numerical Simulation of Vortex Shedding and Lock-in Characteristics for a Thin Cambered Blade

2007 ◽  
Vol 129 (10) ◽  
pp. 1297-1305 ◽  
Author(s):  
Baoshan Zhu ◽  
Jun Lei ◽  
Shuliang Cao
Keyword(s):  
Numerical Simulation ◽  
Vortex Shedding ◽  
Forced Oscillation ◽  
Tvd Scheme ◽  
Convective Term ◽  
Variation Diminishing ◽  
Vortex Shedding Frequency ◽  
Shedding Frequency ◽  
Lock In ◽  
Phase Differences

In this paper, vortex-shedding patterns and lock-in characteristics that vortex-shedding frequency synchronizes with the natural frequency of a thin cambered blade were numerically investigated. The numerical simulation was based on solving the vorticity-stream function equations with the fourth-order Runge–Kutta scheme in time and the Chakravaythy–Oscher total variation diminishing (TVD) scheme was used to discretize the convective term. The vortex-shedding patterns for different blade attack angles were simulated. In order to confirm whether the vortex shedding would induce blade self-oscillation, numerical simulation was also carried out for blade in a forced oscillation. By changing the pitching frequency and amplitude, the occurrence of lock-in at certain attack angles was determined. Inside the lock-in zone, phase differences between the blade’s pitching displacement and the torque acting on the blade were used to infer the probability of the blade self-oscillation.

scholarly journals NUMERICAL SIMULATION OF THE OBLIQUE WATER ENTRY OF WEDGES WITH VORTEX SHEDDING

Brodogradnja ◽  
2018 ◽  
Vol 69 (4) ◽  
pp. 69-83
Author(s):  
Xiaobin Yang ◽  
◽  
Guodong Xu
Keyword(s):  
Numerical Simulation ◽  
Vortex Shedding ◽  
Water Entry

Numerical Simulation of Vortex Shedding in Tube Arrays

2002 ◽  
Author(s):  
C. Sweeney ◽  
C. Meskell
Keyword(s):  
Numerical Simulation ◽  
Vortex Shedding ◽  
Complex Geometry ◽  
Vortex Method ◽  
Standard Case ◽  
Discrete Vortex ◽  
Element Discretization ◽  
Fluid Forces ◽  
Tube Arrays ◽  
Flow Through

Vortex shedding may occur in tube arrays, resulting in strong excitation forces at discrete frequencies. In the past the Strouhal numbers governing vortex shedding in these systems were determined experimentally. This paper presents a method of numerical simulation for the unsteady flow through a rigid normal triangular tube array and hence provides a method of determining both the frequency of vortex shedding and the magnitude of the fluid forces acting on the tubes. The technique used is based on a discrete vortex method similar to the cloud-in-cell approach which has been applied to flow problems for small numbers of cylinders. However, in the current implementation the flow velocity calculation is carried out on an unstructured grid using a finite element discretization. Thus, the complex geometry associated with a tube array can be easily accomodated. The method, referred to as the “Cloud-in-element” method, is validated for the standard case of flow over a single cylinder and then applied to flow through a normal triangular array with a pitch diameter of 1.6. The Reynolds number is 2200. The Stouhal number obtained from the numerical simulation is 1.27, which is within 6% of the value available in the literature. Qualitatively, the vortex shedding pattern obtained is in agreement with published flow visualization.

scholarly journals BLUFF-BODIES VORTEX SHEDDING SUPRESSION BY DIRECT NUMERICAL SIMULATION

2004 ◽  
Vol 3 (1) ◽  
pp. 03
Author(s):  
P. A. R. Ribeiro ◽  
E. B. C. Schettini ◽  
J. H. Silvestrini
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Vortex Shedding ◽  
Bluff Bodies ◽  
Maintenance Costs ◽  
Splitter Plates ◽  
Virtual Boundary ◽  
High Order Finite Difference ◽  
Fuel Costs

Vortex shedding is responsible for harmful vibrations on immersed structures and for increasing their drag coefficients. Thus vortex shedding suppression is highly interesting in order of decrease maintenance costs of standing structures and fuel costs on moving ones. Vortex shedding suppression is here achieved with the use of splitter plates by means of numerical simulations at a low Reynolds range, Re 100 and 160. For this purpose it has been used a high order finite difference method in association with a virtual boundary method, responsible for the obstacle’s representation. The use of this novel numerical method showed a great concordance with experimental results by means of low computational costs.

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