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Computer simulation has been employed to understand the thermal-flow and combustion phenomena in the burner element to solve operation problems and in search for optimal solutions.
A CFD analysis provides fluid velocity, pressure, temperature, and species concentrations throughout the solution domain.
CFD can also provide detailed parametric studies that can significantly reduce the amount of experimentation necessary to identify problems and to optimize the operating conditions.
Therefore, it is possible to increase the accuracy of the simulations with a minimum number of additional grid points.
The final unstructured grid having 60,432 nodes and 256,084 elements was used in the simulation.

An extension of the model to transient flow and two-phase flow simulation has been done to see the effect of impeller rotation and gas entrainment in the centrifugal operation procedure.
Numerical simulations[4-5] show the possibility to investigate the flow pattern and phenomenon occurs during the pump operation.
Simulation Methodology Geometry Model.
The simulation of the three dimensional flow in the pump was done in the commercial CFD package Ansys Fluent 13.
After the stead state flow simulation has been done, the model is further developed to a trasient flow model with a rotation speed of 3000 rpm and a two-phase flow model of 10% air fraction.

Therefore, many researchers have used computational fluid dynamics (CFD) software to solve problems which can not be solved theoretically and experimentally.
The simulation for the flow velocity field inside and outside the abrasive water jet nozzle has been carried out [2,3].
The simulation model is divided with the hexahedron cell, one of the model is shown in Fig.1.
The k-ξ turbulence model, and the item realizable and non-equilibrium wall functions were used in simulation.
Simulation Result and Analysis The simulation result of Fig. 2 is the velocity field of the three phase flow in the X-Z plane.

In view of all above, CFD analysis had been performed in the work to investigate the aerodynamics of high speed container flat wagon. 2.
CFD numerical analysis 2.1 Governing equations and method Simulations were performed considering the flow as steady, isothermal, uncompressible and using a segregated solver.
It integrates the advantage of k-model in the near wall simulation and k - model in external area calculation [4].
The Application of SST Turbulence Model in the Aerodynamic Simulation of the Automobile.
Large-eddy simulation of the flow around a freight wagon subjected to a crosswind.

Numerical simulation and laboratory experiments was used to research the distribution law of tunnel fire at home and abroad due to the complexity of tunnel fire mechanism.
In English, Cox used CFD to analyze the tunnel fire problem early, ventilation, slope and unstable fire were simulated through establishing the mathematical model of JASM, which simulation results were consistent with experimental results of Zwenberg model [3]; In Japan, M.Dobashi and T.Imai studied vertical and horizontal emergency ventilation systems in the event of a tunnel fire through numerical simulation, and it applied to the tunnel of Higashiyama, in addition, the smoke density varying with time and space was also analyzed [4]; In France, B.Brousse and C.Moret attempted to investigate the smoke spread of different tunnel fire through a three dimensional transient simulation, and it considered the tunnel wall roughness, partial loss of inward and outward and the train piston effect [5]; In America, S.S.Levy and J.
Sandzimier pointed out the relations between the exhaust air rate and smoke control effect, and CFD program combined with Ted Williams tunnel was used to the model of fire [6]; In China, the research on numerical simulation of the tunnel fire started late, Lian Feng employed the method of three dimensional numeric simulation to analyze the fire in certain tunnel and the velocity field and temperature field.
RABT curve and HC curve can better simulate the variation of temperature in the tunnel according to full-scale simulation experiment results of UPTUN.
Mizuno, Numerical simulation of the emergency tunnel ventilation for a tunnel with longitudinal and transverse systems combined, 10th International Symposium on the Aerodynamics & Ventilation of Vehicle Tunnels (2000) [5] B Brousse and C Moret, ID-computer simulations and field fire testing using a chimney limited longitudinal smoke control system, 10th AVVT (2000) [6] S.S.Levy and J.R.Sandzimier, Smoke contral for the Ted Williams Tunnel-a comparative of extraction rate, 10th International Symposium on the Aerodynamics & Ventilation of Vehicle Tunnels (2000) [7] Lian Feng, Wandi Wang, Qixin Yang and Mingnian Wang, J.

Distribution rule analysis and research of wind loads of stadium by numerical simulation Zhixiang Yin1,a, Shuang Zhang1,b College of Architectural Engineering, Liaoning Technical University,Fuxin,Liaoning,123000, China azhixiang_yin@sohu.com, bzs8799@sina.com Keywords: long-span roof; wind load distribution; numerical simulation Abstract.
Numerical simulation method is a new method which is developed with the development of computer technology.
Therefore, in the engineering numerical simulation of wind load often use the SST k- ω model to simulation turbulent flow.
Practical engineering application Based on FLUENT finite element software platform, a gymnasium as an example, using CFD numerical simulation method carry on the research of the roof structure surface wind pressure distribution characteristics.
Numerical simulation of flows around long-span flat roof [J].

Simulation and optimization of turbine blade Shape modification Fang He Xinyu College of Mechanical Engineering 2666 Sunshine Avenue ,high tech Zone of Xinyu,Jiangxi 338004 , People’s Republic of China 514149150@qq.com Keywords:hydroturbine;runner;leaf blade shape modification;CFX;Simulation optimization Abstract:Thickness thinning repair analog simulated using fluid mechanics research tool ANSYS-CFX of mixed-flow turbine runner blade，Through the three-dimensional flow and numerical calculation and analysis of energy distribution on the blade after featheredging.
Introduction This paper used fluid mechanics research tool ANSYS-CFX to cut mixed-flow turbine runner blade thickness thinning for analog simulation.
The mainly is carries on the blade thickness thinning and analysis blade energy or speed. 2 The results of calculation and analysis of numerical simulation of turbine blades In the optimization scheme have been determined, the main numerical on runner blade from the following aspects: the simulated blade speed, blade pressure energy , kinetic energy and total energy.
Finally, the runner blade is thin 0.5cm can obtain numerical performance is relatively good simulation results. 2.1 Analysis and simulation results of velocity distribution From the velocity distribution figure 1 and figure 2, The relative speed of the blade surface in the import side is relatively low, to the outlet side of blade ,especially close to the lower ring, The velocity of the fluid change is relatively large, velocity Uniform distribution,Near the top of blade,The fluid velocity flow better.The working surface of blade inlet flow better, no flow separation, vortex phenomenon; the inlet velocity near the blade ring surface is better; in the back of the blade, no obvious flow separation, transverse flow, inverse flow ,secondary flow, flow in good condition, only near the imported 1/6 around the lower ring ,there is a low zone of velocity .the overall flow condition is good, and the design point is consistent, that leaf thickness thinning 0.5cm it is quite reasonable.
References [1] Chun mei Liu: Analysis of the internal flow in Francis turbine runner CFD [D] XiHua University.2006 [2] Wu xiaojing,liu shuhong,wu yulin.Helicity Application on Analyzing Vortex Rope in Draft tube [C] IAHR Symposiun,Yokohama,2006 [3] Thomas Vekve .The influence of the pressure gradient on draft tube flow at part load operation[C] IAHR Symposium,Stockholm-Sweden,2004

Effect of the Soil Inclination on Natural Convection in Half-Elliptical Greenhouses Djedid Taloub1,2,a*, Abdelkarim Bouras1, Zied Driss3 1Department of Physics, Faculty of Sciences, University Mohamed Boudiaf of M’sila, M’sila, Algeria. 2Laboratory of Renewable Energy and Sustainable Development (LRESD), University brothers Mentouri Constantine 1, Algeria. 3Laboratory of Electromechanical Systems (LASEM), National School of Engineers of Sfax (ENIS), University of Sfax, Sfax, Tunisia aemail: djtaloub@univ-msila.dz Keywords: Heat transfer; half-elliptical; Natural convection; Laminar flow; Multicellular; CFD simulation Abstract.
The commercial CFD code Fluent 6.3 was utilized as a solver to investigate the natural convection heat transfer.
Results and Discussion In this paper we performed numerical simulations of natural convection in a closed semi-elliptic cavity characterized by the eccentricity (e = 0.7), which contains an incompressible fluid of kinematic viscosity ν and thermal diffusivity α, this cavity comprising a half-elliptical "ceiling" upper wall and the "floor" bottom wall, for different lower wall inclination angles δ, (δ = 0 °, δ = 1 °, δ = 3 °, δ = 5 °, δ = 7 °, δ = 9 °, δ = 10 °, δ = 15 °).

Computer Simulation Verification Flow Simulation is a software fully integrated in SolidWorks for computing fluid (gas or liquid) flows inside and outside SolidWorks models, as well as heat transfer to (from, between, in) these models due to convection, radiation, and conduction with a proved computational fluid dynamics (CFD) technology.
Fig. 2 shows the information revealed in the solver of the simulation.
Fig. 4 The flow trajectory plot of the simulation.
Fig. 5 The contour plot of pressure distribution in the simulation.
Fig. 6 The vector plot of pressure distribution in the simulation.

However, they are accompanied by characteristic advantages and disadvantages, which limit their possibilities of application. 3D Computational Fluid Dynamics (CFD.
Within CFD, geometrical and physical conditions are modeled as realistic as possible and boundary conditionas are defined.
Beneficial of the CFD approach is its high accuracy and the ability to realistically model the systems.
Herrán-González et al., Modeling and simulation of a gas distribution pipeline network, in: Applied Mathematical Modelling, volume 33, no. 3, (2009), pp. 1584 -1600
Bermúdez et al., Simulation and Optimization Models of Steady-state Gas Transmission Networks, in: Energy Procedia, volume 64, (2015), pp. 130 -139