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An Investigation into the Effect of Design Parameters on Plasma Density in DBD (Dielectric Barrier Discharges) Jong-Bong Kim1, a and Myoung-Soo Shin2,b 1Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul, 139-743, Korea 2LED Lighting Development group, LG Innotek, Hyuam-Ro 570, Munsan-Eup, Paju-Si, Gyeonggi- Do, 413-90,1Korea ajbkim@seoultech.ac.kr, bmsoo82@lginnotek.com Keywords: DBD (Dielectric Barrier Discharges), Plasma, Simulation.
In this study, the plasma density is predicted by a coupled simulation of gas flow, chemistry mixing and reaction, plasma generation, and electric field.
The analyses were carried out using commercial software CFD-ACE [11], and analysis modules for fluid dynamics, chemical reaction and mixing, electromagnetic field, and plasma transportation were included.
The analysis is carried out using commercial software ‘CFD-ACE’.
Fig. 8 Photos of water droplet on the Polyamide film (a)before plasma treatment and after plasma treatment with electric power of (b)150 W, (c)180 W, (d)210 W, and (e)240 W Fig. 9 Measured contact angle and calculated ion density for (a) gas velocity and (b) electric power Summary A curtain type DBD plasma generator, which is often used for the surface cleaning of semiconductors, has been subjected to analyses using the commercial code ‘CFD-ACE’.

The three dimension CAD model is imported into the commercial CFD software.
Figure 6 The result of signal processing unit simulation in original design.
Figure 9 The result of signal processing unit simulation in creating vents.
Table 1 COMPARSION OF THE TWO SIMULATIONS RESULTS Components Temperature of the original design in the simulation Temperature of the modified design in the simulation D2 122˚C 104˚C D8 128˚C 105˚C D9 126˚C 105˚C D10 127˚C 105˚C D11 126˚C 105˚C Figure 11 Result of signal processing unit simulation in modified design.
CFD Analysis of an Avionic Module for Evaluating Power Distribution as a Thermal Management Measure for a Double-sided PCB.

This paper studies the spatial concentration distribution and particle tracks of students talking continuously in a classroom with two air distribution methods, including mixing ventilation (MV) and displacement ventilation (DV) using CFD simulations.
This paper studies the spatial concentration distribution of student talking continuously in a classroom with two air distribution methods, including mixing ventilation and displacement ventilation using CFD simulations.
At present, there are three simulation methods for turbulence, which are Direct Numerical Simulation (DNS), Large Eddy Simulation (LES) and Reynolds-Averaged Navier-Stokes (RANS).
The simulation results could be in good agreement with experiment results using RNG k-εmodel, so this study using RNG k-ε model to simulate the indoor airflow.
Because of the high turbulence intensity and the small particle with the size of 5μm used in the simulation, the particles’ movement is mostly influenced by the indoor airflow.

Focus on the unfavorable effects of initial operation to the performance of ground heat exchangers, a three-dimensional CFD simulation of full-scale ground heat exchanger under dynamic load was established to investigate the heat transfer performance of a 120-meter vertical U-Tube ground heat exchanger under different initial operating time.
In order to find possible reasons, a three-dimensional CFD simulation of full-scale ground heat exchanger under dynamic load was established.
Two simulations under the same annual dynamic load and different initial operating time were conducted.
This paper combined with the engineering practice and used building thermal environment simulation software DeST to calculate the dynamic load of a public building in Xi'an for the whole year.
☆ Yan Ling Guan, female, born in April 1957, Ph.D, professor, The College of Environmental Science and Engineering, Chang’an University, Xi’an, Shaanxi, 710054, China E-mail:guanyl@chd.edu.cn References [1] Ingersoll L R, O J Zobel, Ingersoll A C: Heat conduction with engineering, geological, and other applications (USA 1954) [2] Kavanaugh, S P: Simulation and experimental verification of vertical ground coupled heat pump systems (Oklahoma State University 1985) [3] Nairen Diao: Heat Transfer Analyses of Ground Heat Exchangers and Their Engineering Applications (Tsinghua University 2004) [4] Eskilson P: Thermal analysis of heat extraction boreholes( Sweden Lund University 1987) [5] Min Li, Alvin C.K.

Numerical Predication of Two-Phase Flow in Mixing Chamber of the Quick-Contact Cyclone Reactor Yuchun Zhang 1, a, Zhenbo Wang 1,b and Youhai Jin 1,c 1 State Key Laboratory of Heavy Oil, China University of Petroleum, Qingdao 266555, Shandong, China azhangyuchun29@163.com, bwangzhb@upc.edu.cn, cjinyh@upc.edu.cn Keywords: Eulerian model; gas-solid two-phase flow; quick-contact cyclone reactor; numerical simulation; FCC Abstract.
In this paper, the numerical simulation analysis of the quick-contact reactor was carried by using CFD software.
We used CFD software FLUENT6.3.26.
The simulation results are shown in figure 3.
The simulation results indicate that the two-phase flow in mixing chamber is very complex duo to the VGO injection and high turbulence intensity.

The muffler attenuation performance of work is directly related to noise size of vehicle, it relates to environmental pollution[5].In this paper presence problem of exhaust muffler is analyzed, using three three-dimension fluid numerical calculation(CFD) tool velocity and pressure distribution are performed, and sound field also calculated, after improvement experiment is certificated .
Then after exported into computational fluid dynamics (CFD) software flow field simulation is analyzed.
Due to the steady-state condition is equal to the simulation of initial conditions boundary condition, so boundary conditions can be input.
Conclusions Through the above CFD and acoustic field numerical calculation of a vehicle exhaust silencer analysis and calculation, we can get conclusions that in the range of the analyzing speed the insertion loss of 28dB (A) standard is satisfied firstly, and in care of frequency band, set-net tail pipe noise is about small 5 dB (A) than target, secondly compared with the original muffler 7.6 kPa, pressure loss is dropped about 32%.

Impacts of the improvement on the SiC CVD modeling are presented in computational fluid dynamics (CFD) calculations, manifesting the significance of an accurate database.
Computational Fluid Dynamics (CFD) Calculations.
CFD calculations were employed to analyze an impact of thermochemical properties on the deposition rates of SiC CVD.
An impact of the improved thermochemistry on the SiC-CVD simulations at two different pressures, 100 mbar and 1 bar, is shown in Fig. 2.
At low pressure (100 mbar), both simulations show small contributions from CH3SiH2SiH, giving no significant difference between the two databases.

Haitao Bao, used the dynamic meshing technique of the computational fluid dynamics (CFD) software to analyze the distribution and its mechanism of piston wind[3]; Lihui Wang had set up a scale model for the metro operation, in order to make clear the variation law of wind speed from the three- dimensional direction, which makes up for some research black about this part[4].
Many scholars have deeply study the influence of the piston effect on the velocity and temperature field of the subway station: Kuichao Yin analyzed the influence of the piston effect on the velocity and temperature field and long-term variation law of temperature in different seasons and at different times according a large number of experimental data and CFD simulation at Tianjin subway station, he also analyzed the applicability of shielding door with vent[11]; Tao Li took the Dongdan subway station of Beijing Subway Line 1 as example to study the influence of the piston effect on the velocity and temperature in the subway station, and proposd measures to control piston wind effectively and improve the subway environment[12]; Li Jia and his partners simulated the transient process when train entered and left the station using Computational Fluid Dynamics (CFD) software, and analyzed the piston effect on air flow and discussed the role of piston effect on natural ventilation at the station
Shuyun Dong summed ​​up the impact of the piston wind on load through experiment and numerical simulation, and confirmed that effective use of the piston wind is one of energy-saving measures, which could reduce the energy consumption of subway ventilation and air conditioning system[15].
Yun Han, Lei Zhao used numerical simulation to study the effect on subway tunnel ventilation for different shaft forms, and pointed out that direct draught relief shaft was more advantaged then the skew shaft[17].
Xi'an: Xi'an University of Architecture and Technology, 2010 [3] Haitao Bao: The Numerical Simulation of the Piston Wind in Subway Station[D].

The implementation of developed procedures called User Defined Functions (UDFs) working interactively with Fluent CFD code, and a dynamic mesh method, allows to treat the problem with its specific and complex boundary conditions.
Modeling could be used to simulate these complex mechanisms, it allows saving much time and money, and yields to interesting results that could be exploited to optimize the process.The implementation of developed procedures called User Defined Functions (UDFs) working interactively with Fluent CFD code [3], and a dynamic mesh method, allows to treat the problem with its specific and complex boundary conditions.
Fig. (2) Simulation of four layers formation by laser cladding, using the VOF method Dynamic mesh approach.
Fig. (3) Sequences of butt joint formation We consider in our simulation the calculation field with its dimensions as given on figure (4).
The UDFs were used interactively with the CFD Fluent code, during the calculation process.

Investigation of Drag Reduction due to Dimpled Surfaces in Narrow Channels by Means of Flow Simulations Julian Praß1,a*, Jörg Franke2,b and Stefan Becker1,c 1Institute of Processmachinery and Systems Engineering, Cauerstraße 4, 91058 Erlangen, Germany 2Institute for Factory Automation and Production Systems, Egerlandstraße 7-9, 91058 Erlangen, Germany apr@ipat.uni-erlangen.de, bjoerg.franke@faps.fau.de, csb@ipat.uni-erlangen.de *corresponding author Keywords: CFD, RANS, Dimples, Drag Reduction Abstract.
All geometries were studied under two different flow conditions ReH ≈ 2 430 and ReH ≈ 4 860 using Reynolds averaged Navier-Stokes equations (RANS) within the commercial computational fluid dynamics (CFD) code ANSYS CFX®.
For this reason, the simulations were run until residuals fell below 10−6.
Afterwards, the average pressure difference ∆P was calculated from the last 300 iterations of each simulation which was uses as new boundary condition for a second simulation on the corresponding geometry.
This result proves the suitability of the meshes used for the simulations of dimpled walls.