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The paper combines CFD simulation and high-speed observation experiments to analyze the forming mechanism of high-speed cavitation flowing inside V-groove.
Introduction As for the cavitation in hydraulic valves, worldwide studies have mainly focused on measuring the cavitation development state of hydraulic components using critical cavitation number, determining the critical cavitation number through simulations or experiments, and studying the correlations between cavitation number and physical quantities such as pressure, flow and temperature etc.
This paper is based on the previous research, the V-groove parameters are in reference [4], experimental setup, measurement system and simulation parameters are available in reference [5] [6].
As the cavitation phenomenon in the throttle groove is mainly related to the pressure distribution in the groove and the location of the low-pressure area, we first make an introduction by combining the simulation results in order to get an intuitive understanding of the pressure distribution situation inside the vortex.
Fig. 4 Comparison of Simulation Results of Pressure Distribution inside the Valve Port and the Visual Observations of Cavitation Flow Field (V02, see reference [4]) Summary No matter how the depth and opening of the V-valve port change, there will not be any cavitation at the bottom of the throttling groove.

Simulation model of fan cavity hydrostatic thrust bearing, three-dimensional mathematical model in guide rail is set up.
Using CFD principle, FIUENT and ANSYS Workbench software, temperature field, pressure field and deformation field of hydrostatic bearing is simulated.
Finite element numerical simulation in the application of hydrostatic bearing design [J]. bearings2005,(11):1-3 [3] ZHANG Yan-qin, YU Xiao-dong.
Numerical simulation of temperature field in large size hydrostatic bearing[J].
Numerical simulation analysis of sector and circular oil recess temperature field of heavy hydrostatic[J].

CFD Models of Internal Nozzle Flow and Spray Nozzle model.
The fuel is injected in a constant volume chamber, and the simulation for zone for the spray is simplified as a box with length of 12cm, width of 6cm and height of 6cm.
A transient nozzle flow simulation was carried out and the simulating data was written to a file with a predefined temporal resolution.
Fig.7 The structure of three types of nozzles Fig.6 Spray formation of single and coupling spray Spray simulation coupled with different types of nozzle flow.
The simulation of spray coupled with cavitating flow in nozzles performed via FIRE is helpful to disclose the relationship between the two parts.

Numerical Simulation of 3-D Chemical Non-equilibrium Flow in the Afterburning chamber of Solid Ducked Rocket Cui Li-kun 1, a, Zhang Yong-zhi 2,b and Li Zhuo 3,c 1 College of science of Inner Mongolia university of Technology, Hohhot, Inner Mongolia Autonomous Region, China； 2 Hohhot Vocational Colleges, Hohhot, Inner Mongolia Autonomous Region, China； alekuncui@sina.com, bzhangyong-zhi@sina.com, cli_zhuo@263.net Keywords: Solid Ducked Rocket; Afterburning chamber; Numerical simulation; Chemical non-equilibrium flow Abstract.
In order to reveal the complex turbulent combustion processes in the afterburning chamber of Solid Ducked Rocket(SDR), Based on the fundamental equations of hydrokinetics and elementary principles of radical reaction kinetics, using multi-component chemical reaction equation of containing Mg and Al components, the numerical simulation of chemical non-equilibrium flow in the afterburning chamber of SDR is processed and effects of the air inlet angle on the afterburning chamber is studied by using Fluent software.
Currently, many numerical simulations and experimental researches about afterburning chamber of solid ducked rocket were processed in the domestic and overseas.
In this paper, using multi-component chemical reaction equation of containing Mg and Al components, the numerical simulation of chemical non-equilibrium flow in the afterburning chamber of SDR is processed and effects of the air inlet angle on the afterburning chamber is studied.
Conclusion Based on commercial CFD software Fluent, the model of radical reaction kinetics is applied to numerical simulation of flow field.The numerical simulation of chemical non-equilibrium flow in the afterburning chamber of SDR is processed in this paper.

Analysis on Cavitation Performance in Multi-stage Centrifugal Pump Based on Cavitation Model Si Huanga, Jun Guanb School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou, China 510640 ahuangsi@scut.edu.cn, bguanjun8512@126.com Keywords: Multi-stage Centrifugal Pump; cavitation model; cavitation performance; numerical simulation.
The cavitation model and simulation were validated by comparing numerical solutions with tested curve of net positive suction head required (NPSHr) for the pump.
In particular, due to the joint evolution of computer power and the accuracy of numerical methods, it is now feasible to use CFD codes for the prediction of the complex three-dimensional cavitation flow in the entire pump and impeller-volute (or diffuser) interaction[2-4].
As shown in Fig. 5, the simulation results are close to measured results at designed condition and lower flow rates.
a) NPSH=4.91 b) NPSH=1.82 c) NPSH=1.41 d) NPSH=1.32 Fig.6 Vapor phase distribution in the front view of impeller in different NPSH a) NPSH=4.91 b) NPSH=1.82 c) NPSH=1.41 d) NPSH=1.32 Fig.7 Vapor phase distribution at the back of blade in different NPSH Conclusion Cavitation model based on Rayleigh-Plesset equation was applied in this study to simulate 3-D turbulent flow field and to predict cavitation performance of multistage centrifugal pump. 1) We know that the bubble distribution with changes of pressure and flow. 2) The comparison of calculated value and measured result of NPSHr shows that the cavitation model is more reasonable at designed condition and low flow rate condition. 3) The numerical simulation in this paper could instruct to pump optimization design.

Florian et al. investigated the effect of resonator curvature on the thermoacoustic effect using CFD simulation in his work [2].
He discussed the influence of a curved resonator on the thermoacoustic engine using CFD analysis.
However, no experimental work was carried out as he only focused on the numerical simulation.
[2] Florian Zink, Jeffrey Vipperman, and Laura Schaefer, CFD simulation of a thermoacoustic engine with coiled resonator, International Communications in Heat and Mass Transfer, (2010)

For numerical simulation of the engines the above said models were used.
Because of these assumptions the single zone model is well suited for the simulation of a HCCI engine.
The physical properties which are used in this simulation model are listed in Table 1.
[14] Kong SC, Marriott CD, Reitz RD, Modeling and experiments of HCCI engine combustion using detailed chemical kinetics with multidimensional CFD, SAE 1026 (2001) 1007-1044
[23] Noel L, Maroteaux F, Ahmed A, Numerical Study of HCCI Combustion in Diesel Engines Using Reduced Chemical Kinetics of n-Heptane With Multidimensional CFD Code, SAE 01 (2004) 1909.

The results provided by numerical simulation of wind action on the building were used to make a comparative study between different patterns of wind fences.
In order to identify an optimal solution for reducing the wind pressures on the external walls of the building, a series of numerical simulation were performed in Ansys CFX.
Comparing the results obtained from the numerical simulation, the porous wind fences represent the best solution for a small distance (1 meter) between the wind fence and the building.
Furthemore, the numerical simulation shows that for the same porosity (10%) the pattern of the pressure distribuition on the building is strongly related to the patern of the wind fence.
[8] Franke, J., Recommendations of the Cost Action C14 on the Use of CFD in Predicting Pedestrian Wind Environment, The Fourth International Symposium on Computational Wind Engineering (CWE2006), Yokohama, Japan, 2006.

The effects of three different treatment methods including introducing a gap, area contacting and cylindrically bridging on flow and heat transfer performances of structured packed beds of particles were investigated with CFD methods.
In Wang [17]’s study, mixing processes of hot and cold fluids in a tee with and without sintered copper spheres were simulated by Fluent using the large-eddy simulation (LES) turbulent flow model and the sub-grid scale (SGS) Smagorinsky-Lilly (SL) model with buoyancy.
Saturated water convection heat transfer in ordered three-dimensional porous media investigated numerically using a CFD software by Wang [18].
The operating conditions are numerically simulation with no slip adiabatic boundary conditions on the pipe wall by using Fluent software subject to uniform heat flux.
Jiang, Numerical Simulation research on heat transfer and fluid flow for pebble beds, J.

Simulations and experiments test the method of measuring flowrate by measuring the rotation frequency of ball is feasible.
Impeller of swirl generator Because of the symmetrical configuration of the swirlmeter, the field of fluid of 3-Dimensional simulation in CFD software FLUENT is half of the measuring pipe.
Altering the design parameters of impeller, all simulation values are listed in table 1.
(c) The simulation error which the simulation methods are out of accord with the fluid state in pipe.
Analyzing the data of simulations and experiments, the maximal errors of meter coefficient is 7.8%.