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Haitao Bao, used the dynamic meshing technique of the computational fluid dynamics (CFD) software to analyze the distribution and its mechanism of piston wind[3]; Lihui Wang had set up a scale model for the metro operation, in order to make clear the variation law of wind speed from the three- dimensional direction, which makes up for some research black about this part[4].
Many scholars have deeply study the influence of the piston effect on the velocity and temperature field of the subway station: Kuichao Yin analyzed the influence of the piston effect on the velocity and temperature field and long-term variation law of temperature in different seasons and at different times according a large number of experimental data and CFD simulation at Tianjin subway station, he also analyzed the applicability of shielding door with vent[11]; Tao Li took the Dongdan subway station of Beijing Subway Line 1 as example to study the influence of the piston effect on the velocity and temperature in the subway station, and proposd measures to control piston wind effectively and improve the subway environment[12]; Li Jia and his partners simulated the transient process when train entered and left the station using Computational Fluid Dynamics (CFD) software, and analyzed the piston effect on air flow and discussed the role of piston effect on natural ventilation at the station
Shuyun Dong summed ​​up the impact of the piston wind on load through experiment and numerical simulation, and confirmed that effective use of the piston wind is one of energy-saving measures, which could reduce the energy consumption of subway ventilation and air conditioning system[15].
Yun Han, Lei Zhao used numerical simulation to study the effect on subway tunnel ventilation for different shaft forms, and pointed out that direct draught relief shaft was more advantaged then the skew shaft[17].
Xi'an: Xi'an University of Architecture and Technology, 2010 [3] Haitao Bao: The Numerical Simulation of the Piston Wind in Subway Station[D].

Muncii Boulevard, Technica University of Cluj-Napoca, Manufacturing Engineering Department, Cluj-Napoca, Romania anicolae.panc@tcm.utcluj.ro, bnicolae.balc@tcm.utcluj.ro, calina.luca@tcm.utcluj.ro Keywords: CFD simulation, die casting, heat transfer, investment casting Abstract.
For the numerical simulation of the casting process, several mathematical models have been developed and applied widely in the past years.
Filling up with liquid metal Considering that the liquid metal for casting is a viscous fluid, in the simulation stage occur a series of more complex problems in describing physical phenomena that accompany the flow process and filler a mold.
This is as it says [9],[10] a cell-centered finite volume methods, typical of most commercial CFD tools (Computational Fluid Dynamic tools), are computationally efficient, but can lead to convergence problems on meshes that feature cells with highly non-orthogonal shapes.
a) b) Fig. 3 Simulations results a) for flowing, b) for heat transfer The results of Comsol simulation for liquid metal flow in mold and cooling mold, it is presented in table 2.

Numerical Simulation of Two Dimensional Laminar Wall Jet Flow over Solid Obstacle.
Simulations were carried out for different Reynolds numbers.
Kanna and Das [7] carried out theoretical simulation of plane laminar wall jets over a backward facing step.
The present study aims to predict the flow pattern around a solid block under wall jet through the development and validation of an in-house CFD code.
An in-house CFD code was developed and validated with a published result.

This paper investigated the effect of runner and gating optimization in reducing the gas porosity inside casting by evaluating the fluid and thermal distribution behavior in experimental and Computational Fluid Dynamic (CFD).
This paper includes an X-ray of a sample product that shows correlation between gas porosity and CFD results.
Based on localized porosity position, runner and gating system is modified and numerical simulation is carried out for analysis.
CFD (a) Test Piece Geometry (b) Conventional Sample Mold CT Scan (c) Measured Porosity at 16 mm Thickness Probe Position of S, T and U Fig. 2.
Numerical Analysis Results Molten behavior is analyzed based on CFD flow simulation, where the surface plot color range relates to the molten parameters and values during injection molding.

The influence of the capacity-increasing in the trailing-edge cutting of HL240 turbine blade Yu LIN 1,a, Shuren HAN 2,b, Min SHENG 2，c 1 School of Mechanical and Electrical Engineering ,Guangzhou baiyun of school,GuangDong, China 2 School of Electrical Engineering and Automation, JiangXi University of Science and Technology, Ganzhou JiangXi, China 3 School of Mechanical and Electrical Engineering, JiangXi University of Science and Technology, Ganzhou JiangXi, China ajxlgjd@126.com,b yuanyuan_1025@163.com, c beancurdsm@yahoo.com.cn Keywords: Francis turbine; cutting tip; capacity-increasing rebuilding; small electric station Abstract: In the precondition of calculating the flow field around the blade with the singular distribution way, the hydraulic characteristic after cutting the mixed-flow blade is calculated by CFD software , the optimum value of output in HL240-WJ50 water turbine and the influence of the flow field are found out by using that way: when the cutting measure
Flow field’s simulation The distribution situation of the flow field around the blade ’s airfoil is calculated by the singular distribution way, and the airfoil’s pressure distribution is shown in Fig.2(a), the abscissa Arc length is the arc distance of the airfoil’s each point to feed-water edge after cutting, the ordinate is the static pressure distribution of the airfoil’s each point.
NUMECA company's core software is developed on the basis of the CFD software- Europe aerodynamic numerical solver (EURANUS), the CFD is written for the European Space Agency (ESA) by the Fluid Mechanics Department of the Free University of Brussels, Belgium in the 1980s.
FINE / TURBO software package can be used for any compressible or incompressible, steady and non-steady, two-dimensional or three-dimensional viscous or inviscid internal flow numerical simulation.

Based on the finite volume method and the pressure-velocity coupling scheme of the SIMPLE algorithm with the standard k-ε turbulent model, a CFD software was used to solve the Navier-Stokes equations to calculate pressure and velocity of the air flow.
In this study, the finite volume method and the pressure-velocity coupling scheme of the SIMPLE algorithm with the standard k-ε turbulent model were applied by using the CFD software, FLUENT, to compute air pressure and velocity.
The approach Based on the finite volume method and the pressure-velocity coupling scheme of the SIMPLE algorithm with the standard k-ε turbulence model, this study utilized the CFD software, FLUENT, to solve the three dimensional Navier-Stokes equations to study the flow field of a partially porous aerostatic thrust bearing for its velocity and pressure.
In order to simplify the numerical simulation, the following assumptions were made for the flow field: (1).
Simulation techniques Fig. 1(a) illustrated the two-sided partially porous aerostatic thrust bearing and the thrust disk.

Governing equations, turbulence and sound models Applying fluid dynamic CFD package Fluent™ Fluent Inc, this paper simulated the channel flow using superhydrophobic surfaces in 2D and unsteady state.
Based on transient flow simulation results (LES modeling is highly recommended for capturing wide band sound spectrum), time variation of acoustic pressure is calculated with the formulation of Lighthill's Acoustic Analogy.
Simulation results and analysis Receiver 1 and receiver 2 were two sensors which measured the sound pressure generated by superhydrophobic surface and plane surface respectively.
Since the distance of the two sensors were very close to their maching surface and the simulation was under 2d model, the absolute value of the sound pressure at that two point were very hign.
An analysis of superhydrophobic turbulent drag reduction mechanisms using direct numerical simulation [J].

Numerical Simulation of Flow Field in Cylinder of Gasoline Engine Jiao Yunjing; Lin Manqun; Wang Xuan; Wang Xueyan; Yan Xicheng Tianjin university Tianjin internal combustion engine institute（Tianjin ,300072） Email:jiaoyj1234567@163.com Keywords: numerical simulation; flow field; gasoline engine; combustion chamber with pent roof Abstract: By adopting CFD numerical simulation software, the transient state numerical simulation of engine is carried on.
With three-dimensional simulation software, aiming at the question that at high-speed the engine cannot work stably, the intake and compress stroke of gasoline engine with squish chamber was studied by numerical simulation.
The simulation was carried on in two work point that is the maximum power and the maximum torque.
Simulation of flow field and analysis 3.1 Simulation condition The simulation starts at the intake TDC(360°CA) and then ends at compression stroke TDC(720°CA).
In the initial setting of simulation, the area of simulation is divided into two areas that consist of combustion chamber and inlet port.

Research on external flow and heat transfer characteristics of H-type fin tube based on longitudinal vortex Jiang Bo*, Hao weidong, Hu Zhihong, Liu Fuguo (Shandong Electric Power Research Institute, Jinan 250002, China) Key words: Longitudinal vortex, H-type fin tube, CFD, Field synergy Abstract.
CFD method is adopted to study the external flow and heat transfer characteristics of the H-type fin tube based on longitudinal vortex, obtaining the flow field and temperature field distribution in the near wall region outside the fin tube.
In this paper, CFD method is adopted to study the external flow and heat transfer characteristics of the H-type fin tube. 2 Calculation model and solution conditions In order to improve calculation accuracy and precision, a representative section of the H-type fin tube is selected for numerical simulation as shown in Fig.1.

A mathematical model for the simulation of the transport phenomena occurred in the anode of a typical fuel cell is presented here.
This approach has been numerically implemented and solved by using the finite volume method being applicable through the CFD-RC© commercial package.
Further to this simple modeling approach, a more detailed 2-D simulation has also been implemented for the same processes in order to overcome superficial assumptions and mathematical manipulations.
The finite volume method was used through the commercially available software package CFD-RC © for the solution of Eqs. (14)-(17) where the simulated domain was discretized by an unstructured grid.
Eleni Vakouftsi for her technical assistantship in CFD-RC© issues and Mr.