scholarly journals NUMERICAL STUDY ON A SHALLOW WATER MODEL WITH LIGNOSA FROM LARGE-EDDY SIMULATION

2000 ◽  
Vol 44 ◽  
pp. 801-806 ◽  
Author(s):  
Keisuke NAKAYAMA ◽  
Yasushi HORIKAWA ◽  
Keizou EJIMA
Keyword(s):  
Large Eddy Simulation ◽  
Shallow Water ◽  
Numerical Study ◽  
Water Model ◽  
Shallow Water Model ◽  
Eddy Simulation ◽  
Large Eddy

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.

Large eddy simulation modelling of asymmetrical flow structures in a vertical-bending continuous caster

2019 ◽  
Vol 116 (6) ◽  
pp. 636
Author(s):  
Peng Zhao ◽  
Yinhe Lin ◽  
Bin Yang ◽  
Kegao Liu ◽  
Jingrui Zhao ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Large Eddy Simulation ◽  
Casting Speed ◽  
Oscillation Frequency ◽  
Continuous Caster ◽  
Water Model ◽  
Flow Structures ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Coherent Vortices

Transient asymmetric circulations in the vertical-bending section of a continuous caster were simulated using a large eddy simulation (LES) model. The accuracy of the modelling was verified by comparing the jet behaviours, asymmetrical flow structures in the water model, and velocities reported in the literature. Coherent structures play an essential role in the circulations motion in the vertical-bending caster. A classical Q-criterion was introduced to detect and identify coherent vortices to investigate flow structures. The results indicate that coherent vortices in the lower circulation exhibit asymmetrical features, which further reveal the nature of the turbulence behind the flow structures in the caster. Monitoring points were then selected to investigate the motions of the “strong” and “weak” circulatory vortices and corresponding velocity variations at the interface between the vertical and bending section of the caster. The alternative variations show the periodic behaviours of asymmetrical circulations at both sides of the vertical-bending caster. Besides these circulations were interrelated and interacted, they were also affected by the curved section of the caster, which resulted in the asymmetrical flow structures in the vertical-bending caster. Finally, the effects of casting speed and SEN immersion depths on the oscillation frequency of circulations during a continuous casting process were analysed. As the casting speed increased, the oscillation frequency and power spectrum increased accordingly; as the SEN immersion depth increased, the oscillation frequency and power spectrum thereof decreased accordingly.

Very Large Eddy Simulation of Passive Drag Control for a D-Shaped Cylinder

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Xingsi Han ◽  
Siniša Krajnović
Keyword(s):  
Large Eddy Simulation ◽  
Flow Control ◽  
Control Problem ◽  
Bluff Body ◽  
Numerical Study ◽  
Numerical Results ◽  
Complex Flow ◽  
Local Disturbance ◽  
Eddy Simulation ◽  
Large Eddy

The numerical study reported here deals with the passive flow control around a two-dimensional D-shaped bluff body at a Reynolds number of Re=3.6×104. A small circular control cylinder located in the near wake behind the main bluff body is employed as a local disturbance of the shear layer and the wake. 3D simulations are carried out using a newly developed very large eddy simulation (VLES) method, based on the standard k − ε turbulence model. The aim of this study is to validate the performance of this method for the complex flow control problem. Numerical results are compared with available experimental data, including global flow parameters and velocity profiles. Good agreements are observed. Numerical results suggest that the bubble recirculation length is increased by about 36% by the local disturbance of the small cylinder, which compares well to the experimental observations in which the length is increased by about 38%. A drag reduction of about 18% is observed in the VLES simulation, which is quite close to the experimental value of 17.5%. It is found that the VLES method is able to predict the flow control problem quite well.

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