Search results

In recent years, with the extensive use of the fluid mechanical analysis software CFD, some researchers applied the CFD to solve the oil film performances for sliding bearing [5-8].
Simulation of pressure field in hydrostatic bearing with finite element method [J].
Application of CFD analysis for rotating machinery, part 1: hydrodynamic, hydrostatic bearings and squeeze film damper[C].
Research on the dynamic characteristics of hydrodynamic journal Bearing Based on CFD analysis [J].
Numerical simulation of flow in convergent wedge gap[J].

Using CFD type grid to mesh the unit, the substrate material is copper, and working fluid is water.
So when the number of mesh exceeds 24400, the simulation has little dependence on mesh.
Numerical simulations were performed by varying the aspect ratio of the micro-channels in the range.
In the range, 12 aspect ratio are selected to numerical simulation.
(2) From the results of the numerical simulation and analysis，the rectangular micro-channel heat sinks have good working performance when the aspect radio between 10 to 20.

ae-mail : guemmadi_samah@yahoo.fr , be-mail : ouibraah@live.fr *Corresponding author : ouibraah@live.fr Key words: Journal bearing, Lubrication, Maxwell model, Viscoelastic fluids, CFD.
Owing to the complexity of the associated hydrodynamic equations, numerical computation is widely used, involving different CFD (Computational Fluid Dynamic) analysis and programs [2, 4, 5, 8, 10, 11], compared to analytical approaches [12].
Boundary Conditions: We use of course the usual well known boundary conditions [1, 4, 5]: a) for the velocity field: (6) h(q) corresponds to a given fluid particle position in the core and is given [1, 4, 5] by : (7) b) for the pressure and the stress field: (8) Numerical Procedure The above equations systems (2) to (5) together with (6) to (8) for given geometric and kinematic characteristics of this 2D flow, are numerically solved using the CFD package Fluent 6.3 completed by UDF.
Papadopoulos, CFD analysis of journal bearing hydrodynamic lubrication by Bingham lubricant, Tribology International, Vol. 41 pp. 1190-1204. (2008)
Clermont, Numerical Simulations of non-Newtonian flow between eccentric cylinders by domain decomposition and stream tube method Journal of Non-Newtonian Fluid Mechanics, 126, pp. 175-158, (2005)

To make the high efficiency and energy-saving centrifugal pump, using multi-objective optimization design to make hydraulic design of the 500SM35 centrifugal pumps, using CFD technology to simulate the three-dimensional turbulence flow in pump, also make performance experiment and cavitation experiment of the 500SM35 centrifugal pump that have been selfdeveloped.
Make some attempt in the design process of the centrifugal pump impeller, suction chamber and spiral casing: Establishing the multi-objective function model of efficiency, cavitation characteristics and reliability; Determining the appropriate proportion of efficiency, cavitation characteristics and reliability, then make the optimal solution for multi-objective function; Using three-dimensional drawing software to make three-dimensional model of impeller, spiral casing, suction chamber; Using CFD technology to simulate the three-dimensional turbulence flow in pump; Basing the result of numerical simulation and performance experiment of sample pump, to modify the design of pump slightly, make the design more optimal.
Table3 Main parameters of the 500SM35 type centrifugal pump's discharge chamber ⅧQ [m 3/s] v [m/s] ⅧA [m 2] 0.1403 6.36 0.0055 Simulation the three-dimensional turbulence flow in pump Calculation model Basing on unsteady flow to approximated simulate the swirl flow using multiple reference frame model (MRF), solving the area of impeller, suction chamber and spiral casing at the same time, pilling in the standard k-ε turbulence model, make three-dimensional incompressible viscous flow Reynolds-averaged equations and standard k-ε turbulence model closure, and then discrete solution.

The objective of the article is to bring several numerical simulation models about building fire and smoke movement.
With the development of computer, numerical simulation is widely used in the area of fire protection design.
This kind of model is relatively simplified in the simulation.
Field Model The idea of the dynamics of a fire might be studied numerically dates back to the beginning of the CFD (Computational Fluid Dynamics) and the computer age.
[5] Information on http://www.nist.gov/el/fire_research/cfast.cfm [6] Information on http://www.fire.nist.gov/fds [7] Klote J H: Review of CFD analysis of smoke management systems, ASHRAE Trans, 108 (2002) 687-698.

The simulation results show that the new model provides improved predictions of the experimental data.
The resulting second particle source term to the turbulent kinetic energy equation has the form below: (4) Test Cases The experiment of Tsuji et al [6] is employed for the validation of the simulation results.
The simulation was carried out using the commercial CFD code CFX-TASCflow, where a modifiable source code subroutine was used to implement the particle source terms to the and equations.
The simulation results were taken from the outlet region.
For the mean velocity profile as shown in Fig.2, the selected models yield identical simulation results which are the same as the clean flow, while the new model predicts the data reasonably well.

In this paper, we give the detailed CFD analysis of cylinders moving in water according to seismic input, and then present a method suitable for practical usage.
CFD analysis of cylinders moving in water In this section, we simplify the piers as rigid cylinders moving in water, and then calculate the pressures on these cylinders using finite volume method.
For CFD analysis, viscous model is also an important factor which affects the calculating results.
Here we choose the k-epsilon model, the requirement for first wall layer grid size of the model can be determined by an empirical formula: . (2) Our CFD model is a tank filled with 6.5m deep water and air at the rest part, so it is a two-phase flow.
Numerical simulation and analysis A continuous beam bridge with piers in water is modeled into 417 nodes and 415 beam elements, which is shown in Fig4.

Numerical simulation has been conducted to provide guidance of designing the gas supply tube and the nozzles.
From the results of the simulation, the supply gas velocity distribution is very sensitive to the parameters.
In this study, supply gas velocity distribution is discussed for a proposed in-line continuous furnace, through CFD numerical analysis. 2.
Fig 4 The physical model and the mesh in the CFD software 3.
From the results of the simulation, the supply gas velocity distribution is very sensitive to the nozzle diameters.

So the SST turbulence model is chosen for all simulations in our study.
Addad in: Numerical Simulations of Flow and heat transfer over Rib-Roughened Surfaces, 17th Annual Conference of CFD Society of Canada, Ottawa, May 3-5(2009)
Behnia in: Reynolds Averaged Simulation of Flow and Heat Transfer in Ribbed Ducts, Int.
Dhanasekaran, and T.Wang in: Validation of Mist/ Steam Cooling CFD Model in a Horizontal Tube, ASME paper HT2008-56280, Summer Heat Transfer Conference, Jacksonville, Florida, August 10-14( 2008)
Wang in: Simulation of Film Cooling Enhancement with Mist Injection,” ASME paper GT2005-69100(2005).

VOF (Volume of Fluid) simulation has been used as a tool to predict the current investigation computationally by using ANSYS FLUENT CFD software.
Tundish flux simulation.
In the present work only CFD model study was done to investigate the importance of this novel shroud in tundish metallurgy.
In this modification of multiphase simulation, five phases were used.
Rest of the edges of axisymmetric simulation were treated as i.e. wall or axis.