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Latter set of simulations also incorporated higher velocities and was supported by wind tunnel experiments.
VG-inclusive transient simulations used an optimal time step of Δt = 0.0005 seconds with the Courant number ≤ 1 to satisfy the CFL criteria.
All simulations reached a steady state after two flow cycles, mainly due to the diffusivity of Reynolds-Averaged Navier-Stokes (RANS) models.
Figure 4: Wind-tunnel data for 17.5 m/s and CFD validation model for 60 mm position with β=15°.
Based on excellent correlation with wind-tunnel measurements (Fig. 4), the CFD model was deemed to be accurately capturing vortex behaviour.

The results of numerical simulations will be presented in the Part 2.
Robustness, economy, and reasonable accuracy for a wide range of turbulent flows explain its popularity in industrial flow and heat transfer simulations.
Jafarizadeh, Numerical Investigation of Heat Transfer and Fluid Flow Structure Simulation in a Divergent/Straight/Convergent Ribbed Duct, M.Sc. thesis, University of Yazd, Iran, (2006) [4] H.
Wilcox, Turbulence Modeling for CFD, DCW, Industries, Inc, (1994) [11]V.
Chen, Evaluation of Various Turbulence Models in Predicting Airflow and Turbulence in Enclosed Environments by CFD: part-1: summary of prevalent turbulence models, HVAC&R Research, 13(6), (2007) [14]B.E.

Discontinuous Deformation Analysis (DDA) is an emerging numerical simulation technology in rock engineering field, which could be used to analyze discontinuous blocks movement.
Introduction As an innovative numerical simulation technology in the field of rock engineering, Discontinuous Deformation Analysis (DDA) has been extensive attention of academicians around the world, since the Chinese-American academician Dr.
This software is originally only used in the medical field [3].Afterwards, it is widely used to develop Computational Fluid Dynamics (CFD) software [4].The open-source and object-oriented features of VTK allow us to code based on library function and develop a post processing system for DDA conveniently.
[2] Youjun Ying, Jun Yang, Pengwan Chen, Numerical simulation of rock blasting in jointed rock mass by DDA method[J],Rock and soil Mechanics,2010.Jun,vol.31,No.7,2259-2263 [3] Huoling Luo, Yongzhong Xu, The study and realization for 3D reconstruction of medical image based on VTK and MFC[J], Journal of Biomedical Engineering,2010,vol.3,No.1, 23-28
[4] Andreas Gerndt, Bernd Hentschel, Marc Wolter, Torsten Kuhlen, VIRACOCHA: An Efficient Parallelization Framework for Large-Scale CFD Post-Processing in Virtual Environments,2004

The air/oil two-phase flow in a simplified bearing chamber model in an aero-engine is simulated by means of discrete phase model (DPM) and wall-film model with CFD approach.
The simulation results coincide with the existing experimental data.
Therefore, numerical simulation is an efficient method.
Therefore, it is indicated that numerical simulation model is right.
Results of numerical simulation coincide well with experiments data which verify the calculation model.

The mass quantity in and out the bearing is equal: in outQ Q= (7) CFD Simulation of Porous Material CFD simulation has been conducted by using Solid-Fluworks, as shown in Fig. 4.
The parameters of the simulation are shown in Table 1.
Table 1 The Parameters of Simulation Item Value Clearance between support surfaces 0.01mm Porous permeability 0.1 Porous material Thickness 15mm Diameter Φ80mm Inner diameter of inlet Φ4 Pressure of inlet 0.4Mpa Pressure of outlet 0.25Mpa Experiments and results Sliders with porous bearing were manufactured to test the micro-vibration resisting characteristics; their stiffness can be reached to 500N/µm.

Numerical simulation of three-dimensional transient turbulent flow in the whole flow passage of a Francis turbine were based upon the large eddy simulation(LES) technique on Smargorinsky model and sliding mesh technology.
The Physical model of simulation The simulation is for a model full-flow of the giant unit, which over-current components are: scroll, vanes, guide vanes, runner, draft tube.
Before the large eddy simulation, the standard k-ε model was used for the steady simulation, and the flow data upon steady simulation with will be as the initial conditions for the unsteady simulation.
Because the CAVATION module was not taken into account during the simulation, the simulation results do not produce steam separator, therefore, the low pressure center will not appear with steam cavity.
[4] FuJun Wang, The analysis for Computational Fluid Dynamics—the theory and application of CFD[M].TSINGHUA University Press,2004

,Ltd, Jincheng, China, 048102 awangweishu@ncwu.edu.cn bljbaihe@163.com Keywords: supercritical pressure W-flame boiler; NOx emission; coal combustion; numerical simulation Abstract.
In this paper, software CFD is used to numerically study the generation rules of NO under different conditions in supercritical W-flame boiler, the influence of pulverized coal concentration and primary air velocity to the generation of NO is analyzed, so that the NO emission at furnace exit can be decreased and references can be provided for the field operation of boiler unit.
Simulation results and analysis The influence of pulverized coal concentration to the release characteristics of NO.
(a) (b) Fig.4 (a)NO concentration distribution at furnace exit when the velocity ratio with the basic condition is 0.9 (b)Average NO concentration distribution of different velocity ratios at furnace exit Conclusion In light of a 600MW supercritical W-flame boiler, software CFD is used to numerically study the generation of NO in the furnace with different coal concentrations and different primary air velocity, the following conclusions can be obtained: ⑴ The generation of NO mainly occurs at a distance of 2m-4m from the primary air vents in the early stage of coal combustion, then the concentration of NO decreases gradually, because of the oxidation of nitrogen in coke, the concentration of NO increases a little at the nose of the furnace. ⑵ The discharge amount of NO at furnace exit can be effectively reduced by increasing coal concentration.

Simulation is conductedbased on the standard k-ε flow model.
Results and Discussion Fig.5 shows the CFD model with the velocity streamline.
Fig. 5: CFD Velocity Streamline Model.
Table 1: Simulation results of angle vs.
Feng, Two dimensional simulation and analysis of the flow in supersonic separator, J.

Simulation of the main ecological parameters Simulation of overshadowing and sunlight hours.
Simulation and prediction of environmental noise.
Simulation of wind environment.
Simulation of weak wind zone.
Wang, in: Computational Fluid Dynamics Analysis—CFD Principles and Applications, edited by Qinghua University Press, Beijing (2007) (in Chinese) [3] Z.F.

the partition period of thermodynamic calculation and the numerical simulation for lignite blended supercritical boiler Cai-ying BANa,Xu-ao LU,Jian-meng YANG,Xu RAN,Feng-ying LIANG North China Electric Power University, Baoding 071000, China Emaila:15830930756@163.com Keywords: Power plant boiler.
Numerical simulation.
The purpose of this paper is to study the impact of furnace temperature and load after blending in lignite, based on CFD software FLUENT-6.3,this paper choose the appropriate geometry model and the physical and mathematical models, and numerical simulation of the different conditions 600MW supercritical once-through boiler blending lignite furnace combustion process is curried out.
[2] Qian Wang .Bituminous coal boiler mixed burning lignite numerical simulation and experiment- al research.
[3] Qingyan Fang .Low volatile coal and blended coal combustion numerical simulation and experi- mental research.