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Numerical simulation of the effecion of inlet velocity in GaN growth by MOCVD Dongsheng Peng*, Zhigang Chen, Congcong Tan Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China E-mail:* pengdongsheng@163.com Keywords: Numerical simulation, Inlet velocity, GaN, MOCVD Abstract.
Based on the simulation results, discussion is presented in this paper to offer the possibility of better control of the GaN film growth process and to ultimately lead to an optimization of the process.
Previous studies on the temperature in MOCVD reactor chamber focused on the simulations of parameters such as the gas flow in the reactor and the shape of the reactor [5,6].Computational fluid dynamics (CFD) simulation is considered as a significant approach to predict the GaN film growth rate and to examine the dependence on various critical parameters.
CFD simulations, considering gas-phase and surface chemical reactions, were carried out using the commercial software Fluent, based on a finite-volume approach.
Conclusions The CFD has been used to simulate a two dimensional mode of GaN deposition in a vertical MOCVD reactor.

The objective of this work is to show key steps of the simulation process focusing on interactions between fluid and structure domain and to review relevant simulation results.
In the field of shock absorber research, Martins et al. [4] presents a development and validation of a CFD model to investigate the oil flow in a shock absorber.
Guzzomi et. al [5] present an FSI approach towards prediction of a valve system performance by coupling the valve disc stack deflection with the CFD pressure results.
The most import process affecting the quality of simulation is the preparation of the mesh.
Spogis: Development and validation of a CFD model to investigate the oil flow in a shock absorber, SAE Technical Paper 2005-01-4030

Numerical Study of Fluid Behavior Induced by Anchor Impeller in a Stirred Vessel AMINE Benmoussaa*, LAKHDAR Rahmanib and MEBROUK Rebhic ENERGARID Laboratory, University of Bechar, BP417, Bechar 08000, ALGERIA *abenmoussa.a@hotmail.fr, brahmani_l1@yahoo.fr, cmerebhi@yahoo.fr Keywords: Agitated vessel, Anchor impeller, Laminar flow, yield stress, Finite Volume Method, CFD.
In the present paper, we have described in-depth numerical study of the basic fluid mechanics problem of yield stress fluid flow with regularization model of Berovier and Engelman in a cylindrical vessel not chicaned equipped with an anchor stirrer by using computational fluid dynamics (CFD) based on the finite volumes method discretization of Navier - Stokes equations formulated in variables (U.V.P).
Nowadays, computer simulation of mixing flow (CFD) in the vessel is widely used to optimize the stirrer geometries and to get a better insight into the complex flow patterns produced by the interaction between the impeller, the tank internals, and the vessel wall [2].The capability of CFD tools to forecast the mixing behavior in terms of mixing times, power consumption, flow pattern and velocity profiles is considered as a successful achievement of these methods and acceptable results have been obtained [4].
Stirred system Fluid model To study the yield stress fluids which constitute the purpose of this paper, mixing systems are dealt with by numerical simulation.
In the regions where the material behaves like a rigid solid, and in the regions where the material flow with an apparent viscosity [5]: (5) The major difficulty with the constitutive equation (1) and (2) when used for numerical simulation is the discontinuity associated with infinite value of the viscosity whenapproaches τ0.

Discretization For the mesh generation the STL-CAD geometry was imported into ANSYS ICEM CFD 5.1® .
Within the simulation the CFD-code ANSYS CFX-10® was combined with the FEM-code ANSYS 10 Multiphysics® .
The interpolations of the pressure, as the results of the CFD simulation, the pressure onto the woven fibre fabricate (Fig. 8), resulting from the infiltration, are applied as boundary conditions onto the FEA model.
The displacements as structural solution of the FE analysis are feed back as boundary conditions into the CFD mesh.
This interaction between the CFD and FE analysis is continued iteratively until the solution criteria is reached.

The internal flow field and the noise of inlet blocking fault and trouble-free for control valve are numerical simulated by CFD.
In this paper, three dimensional flow model of inlet blocking fault and trouble-free for control valve are established, the internal flow field and noise distribution are numerical simulated by CFD, the results provides the theoretical foundation for further study on the blocking fault of control valve.
Fig. 2 Trouble-free flow channel model Fig. 3 Inlet blocking flow channel model Simulation Settings Meshing Before the CFD simulation, the flow channel models need to mesh.
Fig. 11 Trouble-free local acoustic power Fig. 12 Inlet blocking acoustic power Conclusion Establishing the valve trouble-free and inlet blocking flow model, and applying the CFD numerical simulation of internal flow field and noise, obtained the following conclusions
References [1] Yantao An, Rujian Ma, Yong Wang, Simulation and Analysis the Internal Flow Field of Control Valve Bonnet Leakage, Applied Mechanics and Materials [J], 2013, 425, 2078-2081

This paper adopts the method combining wind tunnel test and numerical simulation, using CFD software to establish the representative building model of round monolayer Earth Building and get the wind load characteristics in different wind direction.
Therefore numerical simulation result is credible, and it is feasible to take CFD simulation technology used in the study of Hakka Earth Building wind load characteristics.
Computer simulation of wind environmental conditions around buildings [J].
Civil Engineering CFD Simulation of Parameters Settings[C].
Evolution of CFD software from academic code to practical engineering software[J].Journal of Wind Engineering and Industrial Aerodynamics,1999,81

By using CFD software, the important parameters of velocity and pressure in the flotation column are analyzed and contrasted.
Three-phase flow field simulation study of oil, gas and water based on microbubble flotation Numerical simulation technology for the three-phase flow studies propose a new research method, this paper will research the three-phase flow field of flotation column based on the commercial CFD software FLUENT.
Since the simplified model is relatively simple, column flotation uses ICEM CFD modeling and meshing.
The geometric model and numerical simulation meshes This model doesn’t exist negative meshes, the minimum is Min = 0.970185, so it can be imported to FLUENT to complete the simulation calculation
Conclusions (1) By using CFD software, the important parameters of velocity and pressure in the flotation column are analyzed and contrasted.

Optimization Design of Gasoline Engine Intake based on CFD Zhou Bin XiChang College XiChang City SiChuan Province China 153104941@qq.com Keywords: Gasoline Engine, Intake, Design, Test, FLUENT, CFD Abstract: This paper analyzed the structure of the intake about 65-gasoline engine, which take into account t of the shortcomings of the lack of intake, a new intake system was re-designed.
(4)Re-arrangement of the cylinder head inlet position, full use of the guiding role of the cylinder wall, form an effective intake swirl. 3 Original and improved CFD simulation contrast In order to shorten the development cycle, save development costs, During new product trial before, first numerical simulation of the original and improved intake, contrast design effect. 3.1 Geometric modeling In order to accurate numerical simulation, as far as possible to simulate the actual intake, used 3D modeling software Pro/Engneer establish geometric model, shown in Figure 3 to Figure 6.
Fig.7 Simulations model Grid Fig.8 Mesh refinement at the valve Seat 3.3 The calculation results Meshed model imported Fluent software to numerical simulation, separately simulated the gas flow that Valve lift of 2mm, 4mm, 6mm, 8mm, 9mm, 10mm, And were calculated the original and improved Ricardo swirl ratio and Ricardo flow coefficient, shown in Figure 9 and Figure 10.
(a) 4500r/min (b) 4000r/min (c) 3000r/min (d) 2000r/min Fig.14 Original and improved p-φ Indicator diagram contrast The result show that, the cylinder head inlet improved design, maximum cylinder pressure elevated, it proved engine combustion been improved, this is the root causes of engine power and economy both improved[3]. 5 Conclusion 1) Through structural analysis of the original 65-type gasoline engine cylinder head intake, improved design of the inlet structure. 2) Fluent simulation results show that, improved inlet swirl ratio and flow coefficient have increased, especially in the valve lift when the larger, swirl ratio improving effect is more apparent. 3) Test results shown that, engine power are significant improvement, improved engine available torque on each speed. 4) Cylinder head intake improved, Engine fuel economy becomes better, engine fuel consumption decreased on each speed.
Thermal structural analysis and optimization of cylinder head and block with different configuration by simulation and measurement.

Furthermore, Izadi MJ[11] carried out CFD simulations for different floor heating models.
A standard model was employed in these simulation .
In this simulation, ˚C，AUST=18˚C.
In this simulation, ˚C;˚C.
CFD Simulation of Temperature Distribution in a Room with Various Under Floor Heating System Models.PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE,2009(1):2319-2329

The solution and the analysis were carried out using finite volume CFD solver FLUENT 6.2.
In this section the three turbulence models used in the numerical simulation are described briefly.
Simulation CFD Model Validation.
In order to validate the proposed CFD model and implement in the presented study, the above mentioned model had been run.
The CFD model was validated through comparison with the ISO pressure drop correlation.