Large‐Eddy Simulation of Three‐Dimensional Flow Structures Over Wave‐generated Ripples

2021 ◽  
Author(s):  
Chuang Jin ◽  
Giovanni Coco ◽  
Rafael O. Tinoco ◽  
Pallav Ranjan ◽  
Jorge San Juan ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Three Dimensional ◽  
Flow Structures ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Eddy Simulation ◽  
Large Eddy

WAVELET MULTI-RESOLUTION ANALYSIS ON LARGE-EDDY SIMULATION OF TURBURLENT FLOW BEHIND A VEHICLE EXERNAL MIRROR

2013 ◽  
Vol 11 (04) ◽  
pp. 1360007 ◽  
Author(s):  
A. RINOSHIKA ◽  
Y. ZHENG ◽  
E. SHISHIDO
Keyword(s):  
Large Eddy Simulation ◽  
Large Scale ◽  
Three Dimensional ◽  
Wake Flow ◽  
Small Scale ◽  
Three Dimensional Flow ◽  
Eddy Simulation ◽  
Multi Resolution Analysis ◽  
Large Eddy ◽  
Resolution Analysis

The three-dimensional orthogonal wavelet multi-resolution technique was applied to analyze flow structures of various scales around an externally mounted vehicle mirror. Firstly, the three-dimensional flow of mirror wake was numerically analyzed at a Reynolds number of 105 by using the large-eddy simulation (LES). Then the instantaneous velocity and vorticity were decomposed into the large-, intermediate- and relatively small-scale components by the wavelet multi-resolution technique. It was found that a three-dimensional large-scale vertical vortex dominates the mirror wake flow and makes a main contribution to vorticity concentration. Some intermediate- and relatively small-scale vortices were extracted from the LES and were clearly identifiable.

scholarly journals Large-eddy simulation study of turbulent flow around a rectangular spur dike

2018 ◽  
Vol 40 ◽  
pp. 05013
Author(s):  
Seokkoo Kang
Keyword(s):  
Large Eddy Simulation ◽  
Three Dimensional ◽  
Recirculation Region ◽  
Three Dimensional Flow ◽  
Vortex System ◽  
Spur Dike ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Acoustic Doppler Velocimetry ◽  
Good Agreement

High-resolution large-eddy simulation (LES) is carried out for investigating three-dimensional flow fields around a rectangular spur dike installed in an open-channel flume. The LES showed good agreement with the measurement obtained using Acoustic Doppler Velocimetry. Analysis of the LES result shows that the flow structure around and in the wake of the spur dike is highly complex and three-dimensional. Namely, flow upstream of the spur dike is featured by a vortex system near the bed, another vortex system beneath the free surface, and a recirculation region in front of the spur dike. All of these flow structures are laterally oriented. Moreover, flow in the wake region consists of a large vertically oriented recirculation region and a smaller laterally oriented recirculation region near the bottom corner downstream of the spur dike.

scholarly journals Large eddy simulation of flow around semi-conical piers vertically mounted on the bed

2021 ◽  
Author(s):  
Yasin Aghaee-Shalmani ◽  
Habib Hakimzadeh
Keyword(s):  
Large Eddy Simulation ◽  
Vortex Shedding ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Navier Stokes ◽  
Flow Structures ◽  
Shear Stresses ◽  
Eddy Simulation ◽  
Large Eddy

Abstract In this paper, details, and results of three-dimensional numerical modeling of flow around the semi-conical piers vertically mounted on the bed in a channel, are presented. For flow simulation, 3-D Navier-Stokes equations are solved numerically using the finite volume method and large eddy simulation (LES). In this study, the semi-conical piers with different side slope angles are tested, and the flow around them is compared with the cylindrical reference pier. Flow structures, vortex shedding behind piers, horseshoe vortices, instantaneous and time-averaged flow structures are presented and discussed. Numerical model results show that the semi-conical piers are eventuated remarkable reduction (up to 25%) in downward flow velocity in the upstream side of the piers, and much more reduction (up to 46%) in bed shear stresses in comparison with the cylindrical pier. Moreover, the model results showed some decrease in vortex shedding frequency for the semiconical piers compared to the cylindrical pier.

Large Eddy Simulation of Cross Flow in Pipe Junction

2018 ◽  
Author(s):  
Jiajun Chen ◽  
Yue Sun ◽  
Hang Zhang ◽  
Dakui Feng ◽  
Zhiguo Zhang
Keyword(s):  
Large Eddy Simulation ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Cross Flow ◽  
Exciting Force ◽  
Navier Stokes ◽  
Pipe Network ◽  
Eddy Simulation ◽  
Large Eddy

Mixing in pipe junctions can play an important role in exciting force and distribution of flow in pipe network. This paper investigated the cross pipe junction and proposed an improved plan, Y-shaped pipe junction. The numerical study of a three-dimensional pipe junction was performed for calculation and improved understanding of flow feature in pipe. The filtered Navier–Stokes equations were used to perform the large-eddy simulation of the unsteady incompressible flow in pipe. From the analysis of these results, it clearly appears that the vortex strength and velocity non-uniformity of centerline, can be reduced by Y-shaped junction. The Y-shaped junction not only has better flow characteristic, but also reduces head loss and exciting force. The results of the three-dimensional improvement analysis of junction can be used in the design of pipe network for industry.

Sign in / Sign up

Export Citation Format

Share Document