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In this study, in order to examine the turbulent flow structure inside fuel assembly with the split-type mixing vanes, simulations were conducted with the commercial CFD (Computational Fluid Dynamics) software, ANSYS CFX R.14.
SAS (Scale-Adaptive Simulation)-SST (Shear Stress Transport) and DES (Detached Eddy Simulation), were used.
In this study, in order to examine the turbulent flow structure inside fuel assembly with the split-type mixing vanes, simulations were conducted with the commercial CFD software, ANSYS CFX R.14.
Total simulation time was 2sec.
Simulation was conducted with the commercial CFD software, ANSYS CFX R.14.

Therefore, it is necessary to take numerical analysis to flow field of recoil system and kinetic problem of recoil and counter-recoil based on computational fluid dynamics (CFD) theory.
Research on recoil mechanism based on the CFD theory The internal flow field of recoil mechanism has been numerically simulated with using CFD theory by a lot of people to study the complex process of media flow inside recoil mechanism and a variety of factors impact the performance of recoil mechanism.
Based on the CFD,Zhou Cheng[6] created a 3D incompressible and viscous model under unsteady condition simulating the turbulent and solid particles movement in the flow field.
Numerical Simulation of Flow Field in A Gun Recoil Mechanism[J].
Flow Field Numerical Simulation and Erosive Wear Prediction of Artillery Recoil Brake[D].

However, uncertainties within CFD simulations are rarely documented and difficult to quantify.
The CFD simulation used the k-ϵ{TTP}1013 turbulence model, and the injected flow was taken to be 40 degrees warmer than the bulk flow, such that flow temperature in the simulation is an analogue for activity the scanner would have detected.
This comparison further illustrates how the 3-D PET data fields can facilitate quantification of CFD simulation outcome validity.
The CFD simulations presented here are not optimized for fidelity to the flow around the rod bundle, and are only offered to illustrate the approach used to compare of PET data to CFD outcomes.
It is a promising validation technique that can use 2D, 3D, and dynamic PET data to validate CFD simulations.

Eulerian-Eulerian approach is used for simulating the two-phase flow for icing simulations in FENSAP-ICE.
All numerical simulations are carried out at the operating conditions specified in Table 1.
Operating conditions used for the simulations.
The time step is set to 1x10-6 for the transient CFD simulations.
CFD based numerical analysis also provided a good insight of the boundary layer flow behavior for both iced and un-iced profiles.

China agaofei_gaofei@126.com, b zjxlypyj@163.com, c limingph@163.com Key words: Air-jet pump; CFD modeling; Simulation; Vacuum degree; Performance Abstract.
The commercial CFD code FLUENT 6.3 was employed as a platform for CFD simulation.
The realizable version of the turbulence model was chosen in this work, since it has been applied by other authors for air-jet pump simulation [3,4].
For each simulation, the solution time is t=2s, i.e., time step size of 0.001s and number of time steps is 2000.
CFD analysis of ejector in a combined ejector cooling system.

Ltd, Hefei 230009, CHINA awangshuwang@jee-cn.com, b1065837079@qq.com, chu-junming@qq.com Keywords: Motor, Temperature Field, Simulation, CFD Abstract.
The fluid-solid-thermal coupling simulation was accomplished by CFD method and the steady state temperature field of the motor under rated condition was obtained.
Based on the calculation of losses, this article established a more accurate motor thermal simulation model, using CFD methods for a certain type of water-cooled permanent magnet synchronous motor with a fluid-solid thermal coupling simulation analysis, and got the steady-state three-dimensional temperature field of the motor.
Simulation Model Calculation Basis of CFD Fluid-Structure Coupling.
Main Simulation Parameters.

To do so, a CFD model is developed in ANSYS Fluent 12.1.
The validation of the CFD model is carried out using data obtained from published literature and good agreement is established between the simulation results and published experimental data.
CFD Simulations The operation of the Earth-Air Heat Exchanger was tested by performing conjugate heat transfer simulations in the commercial Computational Fluid Dynamics solver ANSYS Fluent 12.1.
The simulation parameters used in ANSYS Fluent are as follows: a.
General condition - Steady State, pressure based numerical simulation b.

Based on CFD software, Navier-Stokes equations, Sparlart-Allmaras turbulence model and the structure mesh method, the whole flow passage of Francis turbine were 3-D numerical simulated.
Introduction In recent years, with the development of the computer and CFD technology, 3-D numerical simulation are being applied to turbine system design and modification.
According to some specific hydropower station, To take the numerical simulation method to find the old turbine problem, On this bases improvement should be taken,then to prove its effectiveness by numerical simulation , this can save time, improve the computational efficiency [1~2].
Using Navier-Stokes turbulent equations and Sparlart-Allmaras turbulence model, numerical simulation of the internal flow field was done.
Computational fluid dynamics (CFD software analysis - principle and application ) [M].

China axdwang@mail.neu.edu.cn, b120040622@163.com, cwangtian6809@163.com Keywords: butterfly valve; large diameter; flow characteristics; CFD simulations Abstract.
A numerical approach was used to investigate the flow characteristics around a butterfly valve with the diameter of 2108 mm by the commercial computational fluid dynamics (CFD) code FLUENT6.3.
The simulation was carried out to predict flow field structure, flow resistance coefficient, hydrodynamics torque and so on, when the large diameter butterfly valve operated at various opening degrees.
Fig.1 geometric structure of butterfly valve The experimental study to the flow characteristics around a butterfly valve has been more and more difficult with the diameter of butterfly valve increasing, and the Computational fluid dynamics (CFD) is a good choice as a research tool to investigate and predict complicated flow and heat exchanging processes, and there have been some reports on the flow behavior around a butterfly valve by CFD [3-5].
Numerical Simulations The commercial CFD code FLUENT6.3 is employed as a platform for CFD simulation.

The simulation error is defined as the difference between a simulation result S and the truth T and is composed of additive modelingand numericalerrors ( ).For certain conditions, both the sign and magnitude of the numerical error can be estimated as.
Verification is a process for assessing simulation numerical uncertainty and when conditions permit, estimating the sign and magnitude of the simulation numerical error itself and the uncertainty in that error estimate.Validation is a process for assessing simulation modelling uncertainty by using benchmark experimental data and, when conditions permit, estimating the sign and magnitude of the modelling error itself. 3.2 Research and Application Progress Since the ITTC recommended procedures formed, a more in-depth study of uncertainty analysis in ship model experiment and CFD has been conducted.
Uncertainty in numerical simulation of flow field was analyzed based on the pro of verification and validation.
Uncertainty analysis in CFD for resistance and flow field [J].
Uncertainty Analysis in CFD for Flow Simulation Around Ship Using RANS and DES [J].