Search results

Later, a more complex code based on computational fluid dynamics applied to the simulation of fire development (Fire Dynamics Simulator - FDS) is used to allow a comparison between the numerical results obtained in either way, and to check to what extent some available experimental results concerning similar tunnels can be fitted.
Several models have been developed to simulate fire conditions in tunnels, ranging from simple analytical expressions to complex and computationally-demanding ``zone models'' and ``field models'', the latters based on computational fluid dynamics (CFD) [1].
Successively, a field model based on computational fluid dynamics - CFD applied to fire-development simulation - FDS is used (Pyrosim [5]).The use of CFAST is presented in some detail, as this code is based on the subdivision of a construction into compartments (but there are no compartments in a tunnel!).
A number of simulations were performed by means of CFAST for different values of the compartment length and for the same cross section.
Sharma: Numerical Simulation of Fire in a Tunnel: Comparative Study of CFAST and CFX Predictions, Tunnelling and Underground Space Technology, 2008, 23:160-170 [9] P.

Hydraulic simulation with the particle image velocimetry was adopted to verify the numerical simulation result.
Thus, to determine the velocity field before producing by numerical simulation is very important.
Experiment procedure A computational fluid dynamics (CFD) code, FLUENT, was employed for this study.
In addition, a simulation by PROCAST was conducted, to provide a comparison.
(b) (a) (a) The results in comarison with PIV and other numerical simulation methods; (b) The gate velocity in low pressure casting Fig. 2 Obtained results by PIV test and numerical simulation.

Employing the reverse engineering technology, the three-dimension LED heat sink entity was rebuilt and the heat transfer characteristics of LED heat sink were analyzed by CFD numerical simulation and experimental measurement.
Numerical Simulation.
In numerical simulation, the grid of LED heat sink was built by using Gambit software as shown in Fig. 1(b).
The test grid number was from 1,237,854 to 2,453,362 in the simulation.
In addition, according to the graph of relation, the simulation resultsget agreement with the experimental measuremental result, proving that the numerical simulation can be used to simulate the heat transfer characteristics of LED heat sink accurately.

The piezoelectric domain, structural domain and fluid domain are coupled in the simulation.
COMSOL Multi-physics and simulation analysis COMSOL Multi-physics.
Simulation and analysis.
All of the simulations are done in 2D models to evaluate pumpuing performance of the present micropump with respect to divergence angles of diffusers.
Przekwas: Coupled Fluid-Thermo-Structures Simulation Methodology for MEMS Applications (CFD Research Corporation) [7] J C Lotters, W Olthuis, P H Veltink and P Bergveld: The mechanical properties of rubber elastic polymer poly dimethylsiloxane for sensor application (J.

Green Simulation and the Corresponding Modeling Method In the design field, product design is a very complicated work.
Take green building for example, green simulation and the corresponding modeling method is illustrated.
Now these problems have been fully taken into account in the design stage through fine analysis technique based on the computer numerical simulation.
green building construction plans architectural design electrical equipment professional design main structure professional design equipment construction simulation equipment operation simulation structural stress calculation structural construction simulation wind environment simulation energy consumption simulation light environment simulation acoustic environment simulation emergency processing simulation Fig.3 The computer-aided decision-making system of green building Green Monitoring and the Corresponding Monitoring Content In the past, people put more emphasis on the end of the pollutant control and treatment, while the whole process monitoring and prevention of pollutants are ignored.
Xiang, Application of numerical simulation technology in the design of green building, Focus of attention, 11(2013):26-31 [5] Z.

The capillary jet is simulated by Computational Fluid Dynamics (CFD) method.
Water is used for the simulation and the physical properties of it keep constant at the room temperature of 293K.
The operating parameters and the material properties used in the simulation are listed in Tab.1 and Tab.2, respectively.
The simulation results show that the local micro impurity on the inner orifice wall deflects the capillary jet which deteriorates the jet direction.
The simulation results show that the capillary jet deflects as the decrease of local pressure gradient is not along the orifce axis.

It is robust and simple to program in comparison to Computational Fluid Dynamics (CFD) approaches.
Water is used as a fluid in the simulation so the particles are assigned an initial density of 1000 kg/m3.
However, in the simulation the tank is not emptied completely after about 5 s (see Fig. 3.f).
To match the numerical simulation with the analytical solution Eq. (11) was used with Cv=0.97 and Cd=0.65.
A good agreement is achieved between the numerical simulation and the analytical solution.

The lift curve of the whole aircraft without control surface deflection is gained by CFD calculation which is corrected by wind tunnel test data [3], as is shown in Fig. 1.
The Simulation of Take-off Constitution.
Johnson: Use of flight simulation to complement flight testing of low-cost UAVs.
AIAA 2001-4049, Modeling and Simulation Technologies Conference.
[8] Johnson E N, Mishra S: Flight Simulation for the Development of an Experimental UAV.

The self-sustained oscillation cycle of the open ramp cavity was got by simulation.
With the development of the computer technique, turbulent model and computational method, the use of CFD technology to simulate unsteady flow of cavity more and more.
Gangwar et al. [6] developed a lumped deterministic source term module to model the effect of cavity unsteadiness in gas-path only simulations.
The simulation methods were valid to simulate the cavity unsteady flow.
The self-sustained oscillation cycle of the open ramp cavity was got by simulation at different times.

Experimental apparatus is shown in figure 2.In the following intensive researches, based on hundreds of experimentations and numerical simulations, Purwanto[5] and Pan[6] found the experimental correlations of the slag particles diameter Dp (shown in Eqn.(1)) from the dry granulation method and the flow film thickness h shown in Figure 3 (the equation represented as Eqn.(2)) at the disc edge respectively
Figure 4: Liquid slag feeding mode Figure 5: Boundary conditions To allow for simulation of the interface location of air-liquid, the Governing Equations is given as Eqn. (3) ~ (6)
To gain the numerical simulation, several grids of size 5mm, 4mm, 2mm, 1mm, 0.5mm were used in the 2D simulation.
Xie, Ninth International Conference on CFD in the Minerals and Process Industries, 2012, pp. 10-12