Outline of the three dimensional simulation code

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Validation of a Three-Dimensional Ablation and Thermal Response Simulation Code

Validation of a Three-Dimensional Ablation and Thermal Response Simulation Code

ELORET Corporation, Sunnyvale, CA 94086 The 3dFIAT code simulates pyrolysis, ablation, and shape change of thermal protection materials and systems in three dimensions. The governing equations, which include energy conservation, a three-component decomposition model, and a surface energy balance, are solved with a moving grid system to simulate the shape change due to surface recession. This work is the first part of a code validation study for new capabilities that were added to 3dFIAT. These expanded capabilities include a multi-block moving grid system and an orthotropic thermal conductivity model. This paper focuses on conditions with minimal shape change in which the fluid/solid coupling is not necessary. Two groups of test cases of 3dFIAT analyses of Phenolic Impregnated Carbon Ablator in an arc-jet are presented. In the first group, axisymmetric iso-q shaped models are studied to check the accuracy of three- dimensional multi-block grid system. In the second group, similar models with various through-the-thickness conductivity directions are examined. In this group, the material thermal response is three-dimensional, because of the carbon fiber orientation. Predictions from 3dFIAT are presented and compared with arcjet test data. The 3dFIAT predictions agree very well with thermocouple data for both groups of test cases.
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Three-Dimensional Liver Surgery Simulation: Computer-Assisted Surgical Planning with Three-Dimensional Simulation Software and Three-Dimensional Printing

Three-Dimensional Liver Surgery Simulation: Computer-Assisted Surgical Planning with Three-Dimensional Simulation Software and Three-Dimensional Printing

3D-printed liver model There have been several reports of the use of the 3D-printed models for living-donor liver transplantation, hepatectomy, cardiovascular surgery, and maxillofacial surgery. 20-23 Three-dimensional printing is more useful for understanding spatial relations than 3D models in a 2D display. However, because of the transparent loading material, the conventional 3D-printed model costs approximately $2,000, which is cost-prohibitive (Fig. 4A). Moreover, intrahepatic vessels are difficult to observe because of distortion due to light refraction. Therefore, we have developed a novel 3D-printed frame model (Fig. 4B). 23 Our novel 3D print is produced at a 50% scale and does not use transparent loading material. In addition, the liver surface is covered with several frames along its shape. The user can recognize the external forms by the frames and can see directly inside the structure. Accordingly, our model is less expensive and allows superior visualization. The total cost of the model is US $600, which includes not only materials but also labor, among other costs. The cost of only the materials is less than US
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Three-Dimensional Simulation of Qeshm Channel Currents

Three-Dimensional Simulation of Qeshm Channel Currents

Received: April 2010 Accepted: December 2010 © 2011 Journal of the Persian Gulf. All rights reserved. Abstract Qeshm Channel is a shallow and narrow waterway located between Qeshm Island and the mainland in the vicinity of Hormuzgan Province, Islamic Republic of Iran. This channel is important because of its economic, industrial, fisheries and navigation role it plays as well as environmental issues it presents in the region. A prognostic study was performed to simulate currents in this channel, using COHERENS model. This model is a three-dimensional hydrodynamic model. Simulation of currents was carried out in 20 sigma levels from the seabed to the water surface during one month. It was assumed that the variations of seawater temperature and salinity, four main tidal constituents and the regional wind were the most effective factors in the numerical simulation. Finally, sensitivity analysis was carried out for each factor and the outputs of simulation were verified using the field data recorded by the experts from Iranian National Center for Oceanography. Very good agreements were found between the numerical results and the field data.
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Design And Simulation Of Three Dimensional Bending Machine

Design And Simulation Of Three Dimensional Bending Machine

2 Simulation is very significant in a U-bending design process. Simulation enables to analyze the design in factors of quality, performance, characteristics, and properties of the U-bending before development process. In simulation, finite element method, FEM is used to investigate the precision of U-bending process. The FEM simulation enable to make a clearly identified of the stress distribute in specimen and the parameters changed after visual U-bending process.

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Development of Three Dimensional Simulation on Colon Cancer

Development of Three Dimensional Simulation on Colon Cancer

For Group 1, the user understanding testing is conducted to the waiting patients at Klinik Kesihatan Hutan Percha Melaka. Public viewers will test the product and evaluate on their level of understanding about colon cancer simulation presented. Content testing is the testing that is conducted to the medical staff, including doctor, medical assistants and nurses. These medical staff will test the product and evaluate the validity of the information provided by the product. There are three aspects that user from Group 2 will evaluate on, which are functionality, usability and also user interface. In the functionality testing, the respondent will test the functionality and the smoothness of the animation. The evaluation aspects include animation, content, design, sound, video effects and other multimedia aspects. Meanwhile, in the usability testing, the respondent will evaluate the product after the demonstration process has been carried out. The user will check the contents, whether it is suitable to be used in the hospital and clinic or not. User interface is the process of testing the product’s user interface to ensure it fulfills its specification. The respondents will evaluate whether the interfaces are suitable for this project. Table 2 below shows the details of the testing schedule.
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Development and Verification of the Three-Dimensional 
Electrostatic Particle Simulation Code for the Study of Blob and Hole Propagation Dynamics

Development and Verification of the Three-Dimensional Electrostatic Particle Simulation Code for the Study of Blob and Hole Propagation Dynamics

The blob and the hole, which are intermittent fila- mentary coherent structures along the magnetic field line, are universally observed in the boundary layer plasmas of various magnetic confinement devices [1, 2]. Such struc- tures are considered to play an important role in the ra- dial transport in the boundary layer plasmas. The width of such structures is considered to be in meso-scale. In other words, the width of a small blob or a small hole is slightly larger than the ion Larmor radius. The microscopic, that is, the kinetic e ff ects on blob and hole dynamics should be investigated because of such situations. Thus, we devel- oped the three-dimensional (3D) electrostatic particle-in- cell (PIC) simulation code called “p3bd” (particle-in-cell 3-dimensional simulation code for boundary layer plasma dynamics) in order to study the kinetic effects on blob dy- namics [3–5]. Since the sheath potential in the vicinity of the end plate or the wall is reproduced in the p3bd code, we are able to investigate the sheath effects on blob dy- namics by using the code. In this study, we have updated the p3bd code in order to investigate the dynamics of hole (holes are thought to transport impurity ions [6–8]) and we have verified the code by comparison with the theoretical estimation of blob and hole dynamics. In Sec. 2, we briefly describe the simulation methodology. In Sec. 3, we derive the theoretical estimation of blob and hole propagation dy-
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Nonlinear Three Dimensional Trajectory Following: Simulation and Application

Nonlinear Three Dimensional Trajectory Following: Simulation and Application

Figure 4.6: The vehicle is simulated flying along a pitched, cornered, closed circuit. In (a) are shown the control signals commanded in response to this technically infeasible path. There is one high-frequency pulse in the thrust command, but it is damped quickly. Each pulse in the moment actuator commands corresponds to the start of a cornering turn, and their even spacing implies roughly constant speed throughout. The four most instructive state traces are shown in (b). The hiccup in the speed corresponds to the second turn, from the descending segment into the lower level segment. Each increase in bank angle is a successive right turn. In (c) the vehicle’s simulated flight path is overlaid on the nominal path. As expected, the lookahead guidance logic leads the turns with small overshoot of around two meters on a 40 meter path segment. The trajectory ends after completing a full circuit and turning into the descending segment a second time; until the simulation ends, the simulated path through the final turn in the second circuit is within centimeters of the same path in the first circuit.
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SIMULATION OF TRAIN CONTROL SYSTEMS IN THREE DIMENSIONAL ENVIRONMENT

SIMULATION OF TRAIN CONTROL SYSTEMS IN THREE DIMENSIONAL ENVIRONMENT

Unlike these systems, our developed tools are fully three dimensional. It means that each object has a spatial position and orientation. The three dimensional approach makes pos- sible to create accurate dynamic models, to test new technologies like GPS/GSM-R, or to per- form realistic test runs. Thus, the tool can be efficiently used not just for planning, but e.g. for training locomotive drivers or for demonstrating the operation of various railway safety equip- ments.

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THREE-DIMENSIONAL INSERT MOLDING SIMULATION IN INJECTION MOLDING

THREE-DIMENSIONAL INSERT MOLDING SIMULATION IN INJECTION MOLDING

However, the plastic insert reduce the cooling effects. This paper develops a numerical approach to simulating the mold insert molding in injection-molded part of complex geometry. This developed approach is proved from numerical experiments to be a cost-effective method for true 3D simulation in mold insert molding analysis.

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MOCASSIN: a fully three-dimensional Monte Carlo photoionization code

MOCASSIN: a fully three-dimensional Monte Carlo photoionization code

Once the initial conditions are specified, the frequency depen- dent total emissivities are calculated in each grid cell in order to set up the probability density functions for re-emitted radiation, which are used for the determination of the frequency distribution of the re-emitted energy-packets during the Monte Carlo simula- tion. The energy packets are then fired through the grid and their trajectories computed. Once all the energy packet trajectories have been computed, the Monte Carlo estimators for the mean inten- sity of the stellar and the diffuse radiation fields can be obtained, as described in Section 2.5. The ionization fraction and the elec- tron temperatures and densities must now be updated to be self- consistent with the current estimates of the radiation field at each grid point. This means solving the local ionization balance and ther- mal equilibrium equations simultaneously. The entire procedure is repeated until convergenge is achieved. The convergence criterion that is used in this work is based on the change of the local hy- drogen ionization structure between successive iterations. In some cases, however, this is not a suitable convergence criterion (e.g. in hydrogen-deficient environments), for this reason, other criteria are also implemented in the code (e.g. based on the change of the lo- cal helium ionization structure, or of the local electron temperature between successive iterations), and these can be easily selected by using the appropriate switches in the input file.
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Three Dimensional Numerical Simulation of Stably Stratified Flows over a Two Dimensional Hill

Three Dimensional Numerical Simulation of Stably Stratified Flows over a Two Dimensional Hill

Research Institute for Applied Mechanics, Kyushu University, Kasuga-shi, Japan Abstract Stably stratified flows over a two-dimensional hill are investigated in a channel of finite depth using a three-dimensional direct numerical simula- tion (DNS). The present study follows onto our previous two-dimensional DNS studies of stably stratified flows over a hill in a channel of finite depth and provides a more realistic simulation of atmospheric flows than our previous studies. A hill with a constant cross-section in the spanwise ( y ) direction is placed in a 3- D computational domain. As in the previous 2- D simulations, to avoid the effect of the ground boundary layer that develops upstream of the hill, no-slip conditions are imposed only on the hill surface and the surface downstream of the hill; slip conditions are imposed on the surface upstream of the hill. The simulated 3- D flows are discussed by comparing them to the simulated 2- D flows with a focus on the effect of the stable stratification on the non-periodic separation and reattachment of the flow behind the hill. In neutral ( K = 0, where K is a non-dimensional sta- bility parameter) and weakly stable ( K = 0.8) conditions, 3- D flows over a hill differ clearly from 2- D flows over a hill mainly because of the three-dimensionality of the flow, that is the development of a spanwise flow component in the 3- D flows. In highly stable conditions ( K = 1, 1.3), long-wavelength lee waves develop downstream of the hill in both 2- D and 3- D flows, and the behaviors of the 2- D and 3- D flows are similar in the vi- cinity of the hill. In other words, the spanwise component of the 3- D flows is strongly suppressed in highly stable conditions, and the flow in the vicin- ity of the hill becomes approximately two-dimensional in the x and z direc- tions.
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Three dimensional numerical simulation of thermohaline currents of the Persian Gulf

Three dimensional numerical simulation of thermohaline currents of the Persian Gulf

4. Bower, A. S., W. E. Johns, D. M. Fratantoni and H. Petters, Equilibrium and circulation of Red sea outflow in the western Gulf of Aden, American Meteorological Society, 35:11, 1963-1985, 2005. 5. Blumberg, A. F. and Mellor, G. L., A description of a three-dimensional coastal ocean circulation model. In Three-Dimensional Coastal Ocean Models. ed. N. Heaps, American Geophysical Union, pp. 1-16, 1987.

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Multi-material three dimensional printed models for simulation of bronchoscopy

Multi-material three dimensional printed models for simulation of bronchoscopy

Authors ’ contributions BHHK conducted the study and collaborated with the other authors with respect to the following: CCJ assisted in writing and formatting the manuscript; GJST provided radiological resources, including computed tomography (CT) scans of the thorax, advice on segmentation technique and feedback about the segmented models; WYY supervised the three- dimensional printing of the models; JTHK produced the three-dimensional prints and assisted in post-processing refinement of the models; ALYH assisted in logistics and study planning; MAF assisted in reviewing the study methodology and manuscript reading; SRM proposed the study and super- vised its conduct. All authors read and approved the final manuscript.
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Three dimensional modeling of simulation scene in campus navigation system

Three dimensional modeling of simulation scene in campus navigation system

Keywords: Three-dimensional Modeling; Campus navigation; Simulation scene; Texture _____________________________________________________________________________________________ INTRODUCTION Virtual reality, multi-media and network are said three of the best prospects for computer technology. Virtual reality technology has emergenced as a high-tech in recent years. Virtual reality technology has been one research hot spots in computer science. Virtual reality technology plays an irreplaceable role in the aerospace, military, medical, education and many industries since birth. Its application includes simulation modeling, computer-aided design and manufacture, visualization, simulated driving training, remote machines control, data and model visualization, entertainment and the arts, urban design and planning, and long-distance operation, and so on[1-5]. In China, there has been an increasing number of research institutes and enterprises to do research and product development for virtual reality technology. Virtual reality is a kind of advanced computer interfaces technology in essence. According to applications of virtual reality technology to different objects, its role can be expressed as different forms, such as a concept or idea of visual design and operation, the remote site-to-life effect to any complex environment of cheap simulation training purposes, and so on. It provides users real-time interactive means to maximize user-friendly operation by vision, hearing, touch and other natural and intuitive sense.
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Three-dimensional Simulation of the Field Patterns Generated by an Integrated Antenna

Three-dimensional Simulation of the Field Patterns Generated by an Integrated Antenna

In this paper, we consider a fully three dimensional Voxel based model whose principal aim is to provide a far- field simulation of the radiative field generated by the near-field scattering effects associated with an integrated multi-model antenna. After providing a brief overview of the issues associated with cellular antennas in Section II, Section III introduces the electromagnetic model start- ing from Maxwell’s equations and derives the inhomoge- neous wave equation whose solution is required and con- siders the principal conditions associated with the deriva- tion. Section IV investigates the solution used to evalu- ate the three-dimension electric wavefield pattern in the Fresnel and Fourier zones. This is achieved using a con- ventional free space Green’s function method but using a non-conventional approach to obtaining a series solu- tion for the scattered field. The solution obtained is used in Section V to introduce the principal steps associated with the simulation for a simplified source-reflector sys- tem. Finally, in Section VI, we consider the simulation of radiation field patterns focusing on, by way of an ex- ample, fractal antennas which have properties that are ideally suited for operations over a range of frequencies.
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THREE-DIMENSIONAL SIMULATION OF WATER QUALITY IN A WASTEWATER STABILIZATION POND

THREE-DIMENSIONAL SIMULATION OF WATER QUALITY IN A WASTEWATER STABILIZATION POND

For design purposes, wastewater stabilization ponds (WSPs) are typically assumed to be one- dimensional (1D) plug flow or zero-dimensional (0D) continuously stirred tank reactors (CSTRs). Critically, these models neglect three-dimensional (3D) spatial variability in hydrodynamics; leading to poor characterization of in-pond variability in residence time, waste dispersion and nutrient removal efficiency. This chapter discusses the reliability in using 0D, 1D and 3D models to predict WSP effluent water quality. Comparison of model results reveals that 0D and 1D models overpredicted surface effluent concentrations, with the exception of pH and dissolved oxygen, because they neglect density stratification in the vertical dimension, which was modelled in 3D sequestering nutrients near the bottom. During vertical mixing events, from wind and or influent dynamics, the three models predictions converge.
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Cloth Simulation with Adaptive Force Model in Three- Dimensional Space

Cloth Simulation with Adaptive Force Model in Three- Dimensional Space

Correspondence to: Xuan Luo email: 653011306@qq.com ABSTRACT An adaptive force model is proposed to achieve better performance between the accuracy and the speed of cloth simulation in three-dimensional (3D) space. The proposed force model can be expressed with a general mathematical form demonstrated by the distance between the clothing and the human body. This paper defines how a continuous adaptive area can be established with a shape “block”. It is clarified that, within a specific block, a force model is expressed with the gravity of the clothing, the forces of the adjacent blocks and the anti-force of the human body to the block. In this manner, the force model of the desired clothing can be obtained through a general mathematical expression. The simulations and experimental results demonstrate that the acceptable clothing simulation in 3D space can be achieved with higher speed by saving about 20.2%
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Computer simulation of the dipole artifact in three-dimensional NMR imaging

Computer simulation of the dipole artifact in three-dimensional NMR imaging

A resulting histogram in the absence of the dipole effects with the gradient along the z axis is shown in Figure 6a. The flat region at the center of the projection corresponds to the missing signal intensity due to the air bubble. The resulting histogram when the dipole effect is considered for the same gradient orientation is shown super imposed on the projection without the dipole in Figure 6b. The intensity shifts can clearly be seen which result in the missing intensity in the reconstructed image. This effect can be qualitatively described as the back projected intensities not converging in the reconstruction space. Normally the intensity for a point in the sample space can be represented as intensity along the frequency axis for each projection. During projection reconstruction the intensity is back projected onto an imaging space as shown in Figure 7a. When the intensity is shifted on the frequency axis due to the dipole field, the back projections from the point in the sample space do not converge in the imaging space as shown in Figure 7b and the resulting image has missing intensity at those points. The resultant image of the simulation is shown in Figure 8.
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Numerical Simulation of Three-Dimensional Tsunami Generation by Subaerial Landslides

Numerical Simulation of Three-Dimensional Tsunami Generation by Subaerial Landslides

ter waves overtopped the concrete arc dam, then flooded the village of Longarone, and finally ended 1901 lives (M¨ uller, 1964; Panizzo et al., 2005a). Although often generated in the open ocean, the effects of tsunamis are mostly confined to coastal areas. A tsunami may damage coastal structures such as breakwaters, seawalls, piers, bridges/pillars, artificial floating island/airport and even fish and wind farms (Silva et al., 2000). In addition to their threat to human communities and vital infrastruc- ture, landslides generated tsunami also menaces installations of offshore structures such as platforms, risers, FPSO, pipelines and subsea systems such as manifolds on the continental shelf and slope (Swanson and Jones, 1982; Bruschi et al., 2006). While the mechanism for generation of the initial water waves by purely tectonic mo- tions from earthquake is reasonably well understood, the understanding of landslide generated waves is marginal. More in details, landslide generated tsunami events are commonly classified as three categories based on the initial position of the landslide relative to the water body as shown in Fig. 1.2. These are
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Length estimators for two dimensional and three dimensional images using relative direction chain code

Length estimators for two dimensional and three dimensional images using relative direction chain code

8 1.6 Significance of the Study This study belongs to the mid-level process (1.1) in digital image processing. Due to the superior characteristics of the relative direction chain code over the previous chain code schemes, it is an effective effort to implement these chain codes in image processing methods which their inputs are chain codes. Some attributes of these chain codes which are essential to employ them in estimation of the discrete length have become inquiries. In 2D, the result of implementation of the VCC in length estimators for the first time is explored not only for rectangular grids but also for rectangular and hexagonal grids. In 3D, a curve is considered then it is quantized based on the most efficient quantization method which makes the length estimation more accurate. For both 2D and 3D cases local length estimator is proposed and also 2D global length estimator algorithm.
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