scholarly journals Optimization of the Turbulence Model on Numerical Simulations of Flow Field within a Hydrocyclone

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Yan Xu ◽  
Zunce Wang ◽  
Lin Ke ◽  
Sen Li ◽  
Jinglong Zhang
Keyword(s):  
Flow Field ◽  
Large Eddy Simulation ◽  
Cross Sections ◽  
Three Dimensional ◽  
Reynolds Stress Model ◽  
Computational Grids ◽  
Test Results ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Simulation Results

Reynolds Stress Model and Large Eddy Simulation are used to respectively perform numerical simulation for the flow field of a hydrocyclone. The three-dimensional hexahedral computational grids were generated. Turbulence intensity, vorticity, and the velocity distribution of different cross sections were gained. The velocity simulation results were compared with the LDV test results, and the results indicated that Large Eddy Simulation was more close to LDV experimental data. Large Eddy Simulation was a relatively appropriate method for simulation of flow field within a hydrocyclone.

scholarly journals EFFECT OF THE SPANWISE DISCRETISATION ON TURBULENT FLOW PAST A CIRCULAR CYLINDER

2021 ◽  
Vol 158 (A1) ◽  
Author(s):  
S Kim ◽  
P A Wilson ◽  
Z Chen
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Flow Field ◽  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Three Dimensional ◽  
Scale Model ◽  
Spatial Density ◽  
Eddy Simulation ◽  
Large Eddy

The effect of the spanwise discretisation on numerical calculations of the turbulent flow around a circular cylinder is systematically assessed at a subcritical Reynolds number of 10000 in the frame of three-dimensional large-eddy simulation. The eddy-viscosity k-equation subgrid scale model is implemented to evaluate unsteady turbulent flow field. Large-eddy simulation is known to be a reliable method to resolve such a challenging flow field, however, the high computational efforts restrict to low Reynolds number flow or two-dimensional calculations. Therefore, minimum spatial density in the spanwise direction or cylinder axis direction needs to be carefully evaluated in order to reduce high computational resources. In the present study, the influence of the spanwise resolutions to satisfactorily represent three- dimensional complex flow features is discussed in detail and minimum spatial density for high Reynolds flow is suggested.

Analysis on the Flow Passed a Pervious Cubic-Blunt Body Based on Large Eddy Simulation

2013 ◽  
Vol 353-356 ◽  
pp. 2477-2481
Author(s):  
En Li Ye ◽  
Yi Hong Zhou ◽  
Lei Ren
Keyword(s):  
Comparative Analysis ◽  
Flow Field ◽  
Large Eddy Simulation ◽  
Vortex Shedding ◽  
Blunt Body ◽  
Static Pressure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Eddy Simulation ◽  
Large Eddy

To overcome the deficiency that model experiments are unable to take accurate measurements without damaging the structure of the fine flow fields, a large eddy simulation is employed to simulate the three dimensional structure of the flow passed a pervious cubic-blunt body at Re=2.2×104. A comparative analysis have been taken qualitatively and quantitatively between the flow passed a pervious cubic-blunt body and the flow passed a non-pervious cubic-blunt body from the aspects of the flow structure (mainly including separation and reattachment), unsteady vortex shedding, distribution of static pressure and drag coefficient, etc. Therefore, characteristics of this kind of flow field are concluded and along with a better understanding of concrete effects they bring, which can give guidance to engineering.

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

Towards High-Order Large Eddy Simulation of Aero-Thermal Flows for Turbomachinery Applications

2017 ◽  
Author(s):  
R. Bhaskaran ◽  
Feilin Jia ◽  
Gregory M. Laskowski ◽  
Z. J. Wang ◽  
Umesh Paliath
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Numerical Algorithms ◽  
High Order ◽  
Sixth Order ◽  
Computational Grids ◽  
Variable Order ◽  
Free Stream Turbulence ◽  
Eddy Simulation ◽  
Large Eddy

The solution accuracy and computational efficiency of high order Large Eddy Simulation (LES) solvers are evaluated on two benchmark open literature blade cascade problems. The first problem concerns wake development in the T106A low pressure turbine cascade [1]. The second problem examines the effect of free-stream turbulence on heat transfer from the VKI first stage high pressure turbine vane [2]. The calculations are performed with two independently developed high order LES solvers using completely different numerical algorithms. The first solver FDL3Di [3] was originally developed at the Airforce Research Laboratory (AFRL) and employs structured overset grids. It uses a sixth order compact finite difference scheme in space along with an implicit Beam-Warming scheme for time marching. The second solver, hpMusic, is developed at the University of Kansas [4]. This is a variable order (up to sixth order) unstructured grid solver employing a discontinuous formulation known as flux reconstruction (FR) / correction procedure via reconstruction (CPR) [5]. The computational grids used are independently tuned for each application. The solvers are benchmarked against experimental data for wake development and blade heat transfer coefficient. Further physical insights in to the test cases are also obtained, filling gaps in experimental results, especially for the VKI problem.

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 of stratified mixing in a three-dimensional lock-exchange system

2009 ◽  
Vol 26 (3-4) ◽  
pp. 134-155 ◽  
Author(s):  
Tamay M. Özgökmen ◽  
Traian Iliescu ◽  
Paul F. Fischer
Keyword(s):  
Large Eddy Simulation ◽  
Three Dimensional ◽  
Exchange System ◽  
Eddy Simulation ◽  
Large Eddy

Large Eddy Simulation of Flow and Heat Transfer Mechanism in Matrix Cooling Channel

2017 ◽  
Author(s):  
Yigang Luan ◽  
Lianfeng Yang ◽  
Bo Wan ◽  
Tao Sun
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Transfer Mechanism ◽  
Heat Transfer Mechanism ◽  
Longitudinal Vortices ◽  
Eddy Simulation ◽  
Flow And Heat Transfer ◽  
Large Eddy

Gas turbine engines have been widely used in modern industry especially in the aviation, marine and energy fields. The efficiency of gas turbines directly affects the economy and emissions. It’s acknowledged that the higher turbine inlet temperatures contribute to the overall gas turbine engine efficiency. Since the components are subject to the heat load, the internal cooling technology of turbine blades is of vital importance to ensure the safe and normal operation. This paper is focused on exploring the flow and heat transfer mechanism in matrix cooling channels. In order to analyze the internal flow field characteristics of this cooling configuration at a Reynolds number of 30000 accurately, large eddy simulation method is carried out. Methods of vortex identification and field synergy are employed to study its flow field. Cross-sectional views of velocity in three subchannels at different positions have been presented. The results show that the airflow is strongly disturbed by the bending part. It’s concluded that due to the bending structure, the airflow becomes complex and disordered. When the airflow goes from the inlet to the turning, some small-sized and discontinuous vortices are formed. Behind the bending structure, the size of the vortices becomes big and the vortices fill the subchannels. Because of the structure of latticework, the airflow is affected by each other. Airflow in one subchannel can exert a shear force on another airflow in the opposite subchannel. It’s the force whose direction is the same as the vortex that enhances the longitudinal vortices. And the longitudinal vortices contribute to the energy exchange of the internal airflow and the heat transfer between airflow and walls. Besides, a comparison of the CFD results and the experimental data is made to prove that the numerical simulation methods are reasonable and acceptable.

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