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The flow characteristic and differential pressure-flow of inlet blockage fault and trouble-free for control valve are numerical simulated by CFD.
Fig.2 Valve core shape Fig. 3 Ideal flow characteristic curve Blockage Fault Simulation Flow Model and Meshing At the interface section of valve and pipeline, the block of 80 mm high and 45 °gradient is designed to simulate the internal flow field of inlet blockage fault.
Table 2 Simulation Settings settings solver turbulence model media boundary conditions parameters separating Standard k-ε equation mixed gas pressure inlet / outlet Analysis of Simulation Results Analysis of Flow Characteristic Fig.5 is the flow characteristic of trouble-free and inlet blockage.
Conclusion Establishing the valve trouble-free and inlet blockage flow model, and applying the CFD numerical simulation of flow characteristic and differential pressure-flow, obtained the following conclusions
Process Equipment﹠piping, 2009, 46(2):47-51. ( in Chinese) [4] 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

(a) Pipe geometry model and (b) CFD model CFD Model.
The computational grid that is used for CFD numerical simulation with CFDSOF® is shown Fig. 2(b).
CFD simulation done with inlet Reynolds number of 40900 and turbulent Prandtl number α varies by 1, 1.1, 1.2, dan 1.3.
However, as the many experimental result on curved pipe, the CFD simulation resulted that the secondary flow occur clearly at all variant of α.
Contour of Temperature Conclusions The results of CFD simulation and its analysis deduced.

Numerical Simulation of Internal Flow in Stamping and Welding Multistage Centrifugal Pump Yuanyi Liu1,a, Ruiguang Li1,b and Kai Sun1,c 1School of Mechanical Engineering, Shandong University of Technology, Zibo, 255049, China aliuyy@sdut.edu.cn, brg_lxd@yeah.net, cnetforce@163.com Keywords: Stamping and welding multistage centrifugal pump, Numerical simulation, Impeller, FLUENT Abstract.
Based on the Reynolds time-averagedequations and standardtwo-equation turbulent mode, using multiple reference model and wall function method, the inner flow fields were simulated which is a part of three different kinds of impeller on stamping and welding multistage centrifugal pump by CFD software FLUENT.
Based on this situation, numerical simulation is conducted to one components of the multistage pump containing draft-tube, guide vane and impeller.
This paper selects one component of the multistage pump to go on numerical simulation which reveals the flow condition more truly, calculated region is shown in figure 1.
Wang: Computational Fluid Dynamics—CFD principle of software and analysis (Tsinghua University press, China 2004)

Finally, the hydrodynamic performances of the amphibious robot are analyzed by using ANSYS CFD hydrodynamic calculation software, and the analysis will present a foundation for the design of amphibious robot.
The robot body model is built by the reverse engineer method in UG software, and the speed vector and air pressure distribute are deduced by the numerical simulation of aero-dynamic characters by the CFD module of ANSYS WORKBENCH.
Fig.5, Simplified model of amphibious robot The Numerical Simulation and Establish Physical Model.
According to the simulation results, the fluid smoothly through the robot body surface (the tail of the car except), and did not produce the flow separation phenomenon obviously.
Holmberg,etc: Accuracy of Drag Predictions on Cars Using CFD-Effect of Grid Refinement and Turbulence Models.

But With the development of computational fluid dynamics (CFD) and multi-field coupling technology, economic and efficient numerical methods become the main direction of the current flow structure interaction problems.
The numerical simulation of vortex-induced vibration is mainly divided into: the vortex method and the CFD methods based on different turbulence models.
Conclusion In this paper, through fluent secondary development achieve the numerical simulation about Floating Tunnel fluid-structure interaction analysis and comparison with relevant results, the main conclusions are as follows:1) Floating Tunnel fluid-structure interaction analysis can be achieved by embedding fluent udf language and observed the similar results with the test， these can provide a guideline for the numerical simulation of fluid-structure interaction.2) CFD simulation of floating tunnel vortex-induced vibration can observed the typical phenomena of non-locking and locking region.
[7] XU Feng,OU Jin-ping,XIAO Yi-qing.CFD numerical simulation of flow-induced vibration with different cross-section cylinder[J].
,Numberical simulation of vortex-induced vibration of a circular cylinder with low mass-damping in a turbulent flow[J].Journal of Fluids Engineering,2000,122:694-702

For aeroelastic problems, with the recently well-developed software and hardware, (CFD)-based, nonlinear aeroelastic simulation capabilities have shown that for low to moderate angles of attack, they can be a reliable alternative to linear theories, However, the high fidelity models generally result in very large computational domain easily involving at least 105 and usually greater than 106 degrees of freedom (DOFs).
Results shown in Fig.4 indicate FOM reproduces faithfully the response predicted by CFD, and ready for POD-based ROM construction.
Fig.3 O-type grid for aero-elastic simulation (1) Plunging response (2) Pitching response (3) Lift coefficient Fig.4 FOM and CFD comparison Reduced Order state space model (ROM) Apply a dirac delta signal individually to each structural mode and collect 200 snapshots using a time step ⊿t=5×10-4(s).Given that there are 2 displacement inputs and 2 velocity inputs, this resulted in a snapshot matrix X of primary system with 800 data samples.
Flutter Simulation and Prediction with CFD-based Reduced-Order Model [J].
Flight-Regime Dependent Reduced Order Models of CFD/FE aeroelastic systems in transonic flow [J].

or (4) Based on CFD water jet simulation of the cone straight-shaped nozzle Computational Fluid Dynamics referred to as CFD is through the computer numerical calculation and image display to analysis the system contains the relevant physical phenomena such as fluid flow and heat transfer [5, 6, 7].
Summary (1) When the injection pressure P is 10MPa, because the cone straight-shaped nozzle produce continuous straight jet, and the jet velocity of water jet obtained by the theoretical calculation is 141m/s, also the jet velocity of water jet obtained by the CFD simulation is 139m/s, these two values agree with each other
Simulation of flow field of high-pressure water-jet from nozzle with Fluent.
CFD prediction of the trajectory of a liquid jet in a non-uniform air crossflow.
FLUENT——The fluid engineering simulation examples and application.

Design of ultrasonic ejecting gun used for surface nanocrystallization based on CFD X.M.Wang 1, a , S.N.Ma1, b , C.Q.Li 1,c , J.W.He 1, d and X.Q.
Feng 1, e 1 National Key Laboratory for Remanufacturing, The Academy of Armored Forces Engineering, Beijing, China 100072 a wxm19781217@126.com, b mashining@263.net, cLi_chq@sohu.com Keywords: Surface Nanocrystallization; Ultrasonic ejecting gun; Number simulation Abstract.
The gun with excellent features is premise to obtain the nano-structured layer.This paper analysed the advantages of rectangle Laval nozzle compared to annular-shape one and calculated critical structured parameters of the nozzle.Numerical simulation analysis of flow field of the nozzle at inlet temperature 300K and inlet pressure 0.25 MP, 1.0 MP, 1.7 MP and 2.5MP and velocity field of the gun with divergent-angle extended-barrel conduced by a commercial finite volume code FLUENT software of CFD; Consequently, the overall structure of the gun was optimized and determined finally.

The cross-section area of the CVD tube used for the simulation.
The simulation is represented by the black line in Fig 2.
The simulation was done using a single gas flow without chemical reaction.
Yu et al., “A combined CFD modeling and experimental study of pyrolytic carbon deposition,” Diam.
Grulke, “CFD prediction of carbon nanotube production rate in a CVD reactor,” vol. 387, pp. 307–311, 2004

The CFD method can effectively simulate fluid flow tests [4-5], thus this research has carried out simulation study and compared with the results from NEL.
Simulation results Wall static pressure analysis.
Fig.4 OR comparisons of simulation and expriment Fig.5 Redicted errors OR predicted error of simulation.
(2) The flow process has been simplified in simulation.
Conclusions CFD simulation technology is used in this research to predict the standard Venturi OR characteristics under high pressure.