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Numerical Analysis of Hydrodynamic on Tidal Current Energy Extraction under Marine Platform Liu Jing1, a Ma Yong2, b Li Jiaxin3, c 1,2,3 Harbin Engineering University, Harbin, Heilongjiang, 150001 , China a,b,c980705492@qq.com Keywords: Tidal Current Energy, Tidal Current Energy Generator, Extraction of Hydrodynamic, Numerical Simulation Abstract.
In this paper, different numerical methods on tidal current energy extraction of near-field and far-field hydrodynamic response are used to conduct simulation study.
And the following aspects are used for simulation, including CFD model is used to establish three-dimensional numerical flume, layout plan of more tidal current energy electric generator with different spaces is designed, changes in near-field hydrodynamic are stimulated as well as the calculated results are compared and analyzed, in order to more clearly understand the influence of tidal current energy generator to the surrounding water flow, which has a certain guiding function for the optimization of tidal current energy generator group and protection for the marine environment and ecology.
Numerical Study of Hydrodynamic Response of Generator Tidal Current Energy CFD Model:Fluent is based on the finite volume method (FVM) to solve the governing equation, and it can be combined with other physical models, such as seepage model, multiphase flow model and others.
For more accurate simulation of tidal current energy extraction effect on water level, this paper uses the VOF multiphase flow model in Fluent to process free surface.

Computational fluid dynamics (CFD) has been used before to model porous medium flow in scaffolds and bioreactors [3].
It must be noted that the simulations was conducted without scaffolds because he wants to determine appropriate locations for placing the scaffolds.
However, for the CFD simulation, the scaffold is designed by using SolidWorks 2011.
The fourth step is setting up the CFD simulation.
The fluid flow analysis has been conducted by using CFD, ANSYS Fluent.

,LTD, China albj86868@163.com, b498959126@qq.com, c1020066580@qq.com Keywords: Double-channel with double-suctionpump, Impeller, Volute, Matching Abstract.In order to study the matching optimization of the impeller and volute as well asthe flow characteristics ofdouble-channel with double-suction pump ,this paper based on CFD performance prediction method uses the same impeller to match the volute with different base diameters, guaranteeing the volute inlet width, flow cross-sectional area, and tongue position unchanged .The calculation results show that scheme A with the largest volute base diameter can not only achieve theexcellent energy characteristics and the velocity-pressure uniform distributions, but also the exchange of the fluid energy is more sufficient in the volute.
Because of the above reasons, this paper based on CFD performance prediction method and predecessors' research results, using the same impeller to match different base diameter volutes,study the influence of different base diameter volutes for the internal flow characteristics of the double-channel with double-suction pump.
As can be seen from the Q-H curve, the changingtendency of the simulation and experimental values are basically the same.
In the optimum condition point, the simulation head is 12m, the experimental head is 11.74m.The relative error of the simulation and experimental values is 2.3%.
From the Q-η curve can be seen, the simulation value is slightly higher than the experimental value, which is due to the numerical simulation not considering the pump volume losses and the friction losses between the water and the plate, etc.

Predictive Models for Evaluating Mobility Buses Thermal Performance Luca Evangelisti1,a, Gabriele Battista1,b Claudia Guattari1,c, Roberto de Lieto Vollaro1,d and Luciano Santarpia2,e 1Roma TRE University – Department of Engineering – Via della Vasca Navale, 62 – Rome, Italy 2”Sapienza” University of Rome, DIAEE – Sezione Fisica Tecnica, Via Eudossiana18, 00184, Rome, Italy aluca.evangelisti@uniroma3.it, bgabriele.battista@uniroma3.it, cclaudia.guattari@uniroma3.it, droberto.delietovollaro@uniroma3.it, eluciano.santarpia@uniroma1.it Keywords: Bus, Optimization, Energy, Dynamic Simulation.
In this study two models have been developed by applying the dynamic software TRNSYS, which is widely used to analyze thermal exchanges [2-9], and a CFD model able to reproduce the thermo fluid dynamic processes inside the bus.
On the other hand, considering the frequent bus stops characterized by opened doors and subsequent air changes, the effectiveness of an “air blade system” installed upon the doors has been analyzed through a CFD analysis.
Figure 3 – Air blade system A commercial mobility bus has been implemented with a CFD software, in particular some parameters have been defined: the opening and closing doors phase, which lasts for 30 seconds, the external and internal temperatures, that are set equal to 35°C and 27°C, respectively, and the air knife velocity is fixed equal to 5m/s.
The CFD simulations have been performed within a 3D domain under steady state conditions with Reynolds-averaged Navier–Stokes (RANS) equations according to the k–ε model standard.

In recent years, advanced computer and the mature computational fluid dynamics (CFD) commercial software developed fast, and using the CFD software to acquire hydrodynamic coefficients has the advantages of low cost, variable parameter, shorter time-consuming.
Steady-state maneuverability experiment simulation The simulation of PMM experiment includes steady –state motion simulation and unsteady-state motion simulation .Some parameters in the steady-state test simulation by Fluent should be set as follows: choose the first order implicit solver, SST turbulent model; choose SIMPLEC to compute velocity-pressure coupling; Pressure discretization is Standard and momentum discretization, turbulence kinetic energy discretization and specific dissipation rate are second order upwind.
Unsteady-state maneuverability experiment simulation The unsteady-state maneuverability experiment simulation includes heave motion, sway motion, pitch motion and yaw motion.
The results and the analysis 4.1 All the simulation of experiment is completed．
Hydrodynamic prediction results by simulation system The hydrodynamic coefficients of calculation are used to the simulation system of movement. 5.1 Straight course in horizontal plan.

Moreover, the drag reduction mechanism of herringbone riblets are also confirmed and exploited by CFD. 1.
Its efficiency of drag reduction and physical mechanism are clarified by tests in water tunnel and CFD analysis, respectively. 2.
Fig.5 shows the result of simulation and experiment, the result of simulation for different surfaces have a match with the experiment result.
Fig.4 Experiment results of drag reduction Fig.5 Effect of yaw angle on drag reduction (a) 0° (b) 30° (c) 60° Fig.6 CFD analysis results for yaw angle 0°, 30° and 60° herringbone riblet Summary.
Kim, Direct numerical simulation of turbulent flow over riblets, Journal of Fluid Mechanics. 255 (1993) 503-539

Fluid flow inside radial ventilation duct is one of important facts which to decide the effect of ventilation and cooling, there is important significance to investigate.In this paper,according to the theory of Computational Fluid Dynamic(CFD),a YKK400-6, 690kW medium size high voltage asynchronous motor was taken as an example.Created its 3D stator and rotor radial duct physical and mathematical model,basic assumptions and boundary conditions are determined according to CFD theories.The fluid fields are calculated and analyzed,and fluid field distribution inside radial ventilation duct is shown.Base on the length of the stator ventilation channel as a constant,changing the radial position of the stator ventilation channel peri-axle terminal,and the fluid flow characteristics are shown when the radial position was changed.Analyzing the fluid flow characteristics on either side of the stator winding,and obtaining the influence of the radial position of the stator ventilation channel peri-axle
In this paper,the YKK400-6, 690kW medium size high voltage asynchronous motor is taken for an example.According the CFD theory and three-dimensional finite volume method for building the 3D physical and mathematical model,and solving it.Based on this,for the different radial positions of ventilation channel peri-axle terminal,analyzing their flow characteristic,and obtained some significant results.
The walls of the ventilation channel,upper and bottom layer surface of iron,and outer surface of main insulation are no slip conditions,the fluid velocity is 0on these surfaces.The model inlet pressure and outlet pressure are standard atmospheric pressure.Rotational flow field simulation using multiple reference frame model(MRF).The rotational velocity is 994[8].
● According to the theory of CFD,calculate the flow field inside the radial ventilation duct,obtain the fluid velocity in anywhere.It is found that the past that the fluid velocity is symmetrical along slot center line of radial ventilation duct is incorrect

Effect of groove on performance of splicing fiber in air splicer Zhenyu Wu1, a, Fangyuan Tian1,b and Xudong Hu1,c 1 Zhejiang Provincial Key Lab of Modern Textile Machinery, Zhejiang SCI-Tech University, Hang zhou, China azjuwuzhenyu@gmail.com, blaotian0329@163.com, c xdhu@zstu.edu.cn Keywords: splicing; simulation; axial velocity; pressure Abstract.
The result of simulation and experimental shows that: with the increase of inlet pressure, the rotational velocity and axial velocity of air flow also increase for the without groove case.
CFD Model Description Chamber’s Geometry.
The simulation model of chambers is established.
Air Flow in a Pneumatic Splicer by CFD.

Liquid-solid Hydrocyclone Numerical Simulation and Separation Efficiency Analysis Xian-ming SUN1,a*, Lei WEI2,b 1School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073, Hubei, China 2School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, Gansu, China awuhansunshine@163.com, b715480807@qq.com Key words: Hydrocyclone; Numerical simulation; Turbulent kinetic energy; Separation efficiency Abstract: This paper analyses the basic structure and the separation theory of hydrocyclone.
Three-dimension spiral flow theory and CFD method was used to simulate the Φ75mm hydrocyclone.
Results of numerical simulation shows that with the inlet velocity range from 1 to 5m/s and the particle diameters range from 2 to 5um, the hydrocyclone separation efficiency is increasing.
Hydrocyclone simulation Hydrocyclone model establish The hydrocyclone simulation mainly contains establishing physical model, mesh the physical model, confirm the boundary conditions and analysis the results.
Fig. 1 The hydrocyclone structure Fig. 2 The meshing sketch Simulation results and analysis The static pressure in different planes of hydrocyclone was shown in Fig. 3.

For these reasons, the numerical simulation based on the Computational Fluid Dynamics (CFD) is applied widely to investigate the flow character in the precalciner.
In the present work, CFD numerical simulations of three-dimensional turbulent flow in DD-precalciner are studied.
To simulation numerically, using Gambit software (preprocessor of Fluent software) to mesh, as shown in Fig. 3.
Boundary Conditions and Numerical Methods The boundary values in simulation are determined by the thermal data of cement plant with the capacity of the 5000t/d.
Conclusions This paper presented numerical simulation of the two-phase flow in DD precalciner based on Fluent software.