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Furthermore, the relationship between the system pressure and the abrasive volume fraction has been investigated by a numerical simulation.
The present numerical simulation was carried out using Eulerian multiphase model and Standard k-epsilon model which are embedded in FLUENT software [8,9].
In the present numerical simulation, water is treated as primary phase and abrasive (garnet) as secondary phase.
Fig. 5 Static pressure in the flow field Fig. 6 Comparison of the system pressure equation and the pressure values with CFD results Fig. 5 shows static pressure in the flow field of the nozzle with different volume fractions of abrasive under the same inlet boundary condition that volume-flow-rate is 4.4L/min.
In this figure, the pressure values with CFD results were shown as the star symbols, at a volume fraction of 5%, 10%, 15%, 20%, 25% and 30%.

To deal with wind and wave load, a clue is to deal with it as a fluid dynamic problem, in which a Computational Fluid Dynamic (CFD) model is applied to discrete problem[1,2].
Computational Fluid Dynamics, Theory and Application of CFD Software.
Dynamic Response Simulation of Lifting Load System of Ship-mounted Cranes.
Journal of System Simulation, 2007, 39(12): 145~150
Simulation of stochastic process by spectral representation.

Critical velocity is influence by HRR, tunnel slope, cross-sectional shape and other factors, which can be obtained by equations and CFD simulations(refer with: Fig. 1).
Fig.1 Influence of longitudinal velocity on smoke progress by CFD • Failure of jet fan and efficiency change Taking into account the uncertainty of the fire source, once the fire broke out at the bottom of the jet fans, the group jet fan can’t work and therefore need to consider safety factor(for one group for reserve) .
Applied Mechanics and Materials Vols. 405-408 (2013) pp 1273-1277 [6] Eui Ju Lee, Chang Bo Oh, Kwang Chul Oh, Yong Ho Yoo Hyun Joon Shin ，Performance of the smoke extraction system for fires in the Busan–Geoje immersed tunnel[J].Tunnel and Underground [7] Space Technology,2010,Vol.25,600-606 Chi-Ji Lin, Yew Khoy Chuah: A study on long tunnel smoke extraction strategies by numerical simulation,Tunnelling and Underground Space Technology 23 (2008) 522–530[J].

Aerodynamic analysis of the rotor/wing in conversion flight Jianghao Wu1,a and Jie Hu1, b 1 School of Transportation Science and Engineering, Beihang University, Beijing, PR China abuaawjh@buaa.edu.cn, bbh38134101@qq.com Keywords: Canard Rotor/Wing, aerodynamic characteristics, conversion flight, numerical simulation Abstract.
Computational model and validation The finite volume method is used to carry out the numerical simulation of the rotor/wing in conversion flight.
To validate the effectiveness of simulation, Caradonna &Tung (C-T) rotor is tested to compare the numerical results with the experimental ones.
Figure 2 gives the comparison of pressure distribution at 0.68R and 0.96R blade section between computational fluid dynamics (CFD) results and experiment data.
It is obvious that CFD results have a good agreement with experiment data no matter at which cross section of the blade.

Study of airship stability based on a low resistance profile Shouchao Gu1, a, Dongxu Liu2,b and Yufu Wang3,c 1 School of Aeronautic Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, China agushouchao_buaa@163.com, bliubuaa@163.com, c justin-psp@163.com Keywords: Stratosphere airship; CFD; Tail layout; Stability analysis Abstract.
Numerical simulation was conducted to investigate the external flow around airships with different tail layout, with the help of FLUENT 14.5, based on the incompressible Navier-Stokes equation and SST turbulent model.
Fig 1 Airships with different tail forms Numerical Simulation Method Governing equation.

CFD method has been used widely in the researches on the flow characteristic of airflow origination.
A numerical simulation was performed on characteristics of airflow origination in CRH2 EMU, adopting the method of LES with 10 PCs parallel operations in this article.
Simulation Method of LES Adopting filtering operations for incompressible N-S equations , quality equations and energy equation ,Eq.1 can be reached
In order to improve the accuracy of the simulation, the method of extended calculation boundary is used, the revised balance layer model is used for wall-function.
[5] Grotzbach: Direct Numerical and Large Eddy Simulation of Turbulent Channel Flows.

The second phase fraction has been measured using Image analysis and Rietweld techniques to verify the simulation results.
The G and V were experimentally determined for directional solidification where as 2D heat transfer modeling was carried out in ComsolTM [6] CFD package to determine the G and V for the gravity casting experiments.
According to the present microsegregration simulation, the increasing trend of second phase fraction with cooling rate in directional solidification experiments (0.05-2.75 K/sec; G is almost constant and V is increases with cooling rate) is mainly due to the contribution of the solute (Al) back diffusion.
The 2D heat transfer simulation result for Cu mould casting (175 K/s) predicts V to be 0.015 m/s which is the highest value among all the experimental conditions in the present study.
Because G and V for the water quenching experiment could not be determined from the CFD simulation, we could not calculate the second phase fraction corresponding to this case.

The CFD analysis was performed using 3- and 5- blades.
Figure 3 shows the CFD flow field of 5- blade’s.
Fig.1 MDU’s 2kW Fig. 2 A photograph of Fig. 3 The 5- blades CFD VAWT the 4kW VAWT speed-flow analysis Fig. 4 Blades system performance Fig. 5 Vertical blade’s master model (Power Efficiency vs Peak-Speed Ratio) Fig. 6 π-shape blades Fig. 7 The completion of blade system Generator rotator poles design The electricity generator rotator poles relates to rated of rotator rotation, and are represented using the following formula [4]: (1) After finishing the rotator design, the number of slots are designed which are related to the poles, phase number and wires winding method.
Table 6 is the simulation of displacement.

Base on the model, the simulation was carried out at the experimental condition of Su et al. (1995).
But unlike normal bubbly flow, the vortex region below the cavity contain extremely high void fraction which may cause challenge for simulation.
In the vortex region, the simulation result is noticed to under-predict the void fraction in the area near the pipe centerline.
This may be caused by the phenomena of bubbles re-entrained into the cavity which is ignored in the simulation model.
Simulation results was found out to under-predict the Sauter mean bubble diameter in the pipe flow region for about 10%.

The effect of asymmetric sinusoidal motion on plunging airfoil aerodynamics was studied by numerical simulations for 2-D flow around a NACA0012 airfoil at Re=1.35×105.
Numerical Method The commercial CFD package CFX 11.0 with an unsteady incompressible and viscous flow solver was applied to simulate the unsteady flow field around the airfoil.
For all the plunging simulations 600 time steps per cycle are sufficient and yield accurate results.
As a result, kh=0.2 was chosen for the simulation at and two reduced frequency k of 2 and 4 were used.
To examine these results in detail, the thrust force and propulsive efficiency for the conducted simulations of kh=0.2 at k=2 and 4 have been investigated in Fig. 4.