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Three-Dimensional Finite Element Method

P is the pressure, I is the unit tensor ( ), and t] is the shear-rate and temperature dependent viscosity. [Pg.127]

On the boundary 6Q of the domain Q, the boundary conditions can be either velocity or traction boundary conditions. [Pg.128]

The finite element procedure begins with the division of the computational domain Q into a set of non-overlapping elements, for example, a collection of tetrahedral elements Q,- Since the Eulerian method is used, the elements are fixed in space. Methods such as the VOF or the level set method is used to determine the moving flow front. [Pg.128]

Let V and Q denote the spaces of admissible functions for velocity and pressure. For test functions w e V and qr e Q, we try to satisfy [Pg.128]

We integrate Eq. 8.46 by part, with help of the Gauss-Green theorem, to obtain [Pg.129]


Taking these effects into account, internal pore diffusion was modeled on the basis of a wax-filled cylindrical single catalyst pore by using experimental data. The modeling was accomplished by a three-dimensional finite element method as well as by a respective differential-algebraic system. Since the Fischer-Tropsch synthesis is a rather complex reaction, an evaluation of pore diffusion limitations... [Pg.215]

The modeling of the internal pore diffusion of a wax-filled cylindrical single catalyst pore was accomplished by the software Comsol Multiphysics (from Comsol AB, Stockholm, Sweden) as well as by Presto Kinetics (from CiT, Rastede, Germany). Both are numerical differential equation solvers and are based on a three-dimensional finite element method. Presto Kinetics displays the results in the form of diagrams. Comsol Multiphysics, instead, provides a three-dimensional solution of the problem. [Pg.221]

Our current direction is to study dynamical processes in atomic and molecular two- and three-body systems. We use a technique which formally is based on the mathematical theory of dilation analytic functions. Numerically these results axe realized though a fully three-dimensional finite element method applied to a total angular-momentum representation. We here show how generalizations of our previously published two-body methods to three-body systems are possible without formal approximations. [Pg.324]

The results presented here were obtained by applying a three-dimensional finite element method (FEM) to eq.(4). However this formalism is to complicated and thus not pedagogical to be used directly in a review text like the present one. We thus first introduce a FEM-realization of the one-dimensional Schrodinger problem[33]. [Pg.332]

Abstract A newly developed numerical simulator of two-phase flow using three-dimensional finite element method is presented in this paper. It is described that the fundamental simultaneous equations, the deduction to implicit pressure explicit saturation formulation and their finite element discretization method. Furthermore, its practical application to the numerical simulation project of predicting Horonobe natural gas product is also introduced. [Pg.605]

YY Cheng, W.L. Cheung, T.W. Chow, Strain analysis of maxillary complete denture with three-dimensional finite element method, J. Prosthet. Dent. 103 (5) (2010) 309-318. [Pg.307]

Umitation by Hght (luminostat y = 1, or photo-limitation y < 1, see Comet, 2010) are presented in Table 2. They are compared with the predictive model calculations presented in this chapter, where the radiative transfer equation was solved using the one-dimensional two-flux approximation for all the simple geometric stmctures of photobioreactors except for reactor PBR 2 (as indicated in Table 2), for which we used the three-dimensional finite element method developed by Comet et al. (1994). As shown in the table, the mean deviation between the experimental results and the model calculation is less than 5% (ie, within the range of the experimental standard deviation), thus confirming the ability of the proposed predictive approach to quantify photobioreactor performance under many conditions of operation. [Pg.94]

A three-dimensional finite element method (FEM) was used for thermal analysis of the CHTR. Figure XXIX-9 shows a steady state distribution of the reactor middle plane temperature (for the case of inlet and outlet coolant temperatures of 1173 K and 1273 K,... [Pg.802]

J. Joch, J. Zemankova and J. Kazda, Analysis of a Chevron Notch Four Point Bend Specimen by the Three Dimensional Finite Element Method, Comm. Am. Ceram. Soc., C154 C155, March... [Pg.330]

The present study attempted to numerically predict residual stress and birefringence in injection molded PC specimens with different thickness, 2.0mm and 6.5mm. Numerical simulations have been done based on a viscoelastic fluid model and commercial software MOLDFLOW by three dimensional finite element methods. The former is used to compute flow-induced residual stress, while the latter for combined residual stresses, including thermal-induced and flow-induced stresses. Effects of processing conditions on the residual are considered by the numerical simulations. As for 2.0mm PC injection molded parts, the predicted residual stresses of viscoelastic model show quite precise in accordance with experimental results. But for 6.5mm PC specimen, Moldflow simulated results have less error. [Pg.824]

Pao W.K.S. Lewis R.W. 2002. Three-dimensional finite element simulation of three-phase flow in a deforming fissured reservoir. Comput. Methods. Appl. M. 191 (23-24) pp. 2631-2659. [Pg.564]

De Hoff PH, Anusavice KJ, Wang Z (1995) Three-dimensional finite element analysis of the shear bond test. Dent Mater 11(2) 126-131 Lee CH, Kobayashi S (1973) New solution to rigid-plastic deformation problems using matrix methods. Trans ASME J Eng Ind 95(3) 865-873 Lewis RW, Ravindran K (2000) Finite element simulation of metal casting. Int J Numer Methods Eng 47(l-3) 29-59 (Special Issue Richard H. Gallagher Memorial Issue)... [Pg.514]

According to the established mechanical calculation model, using the ANSYS finite element analysis software, using the method of plane link system analysis and three-dimensional finite element analysis, under the section size of selected and the load. Six different slope states of straight arch with two articulations are analyzed in stress. Plane frame calculation model shown in Figure 1, three-dimensional calculation model shown in Figure 2. [Pg.380]

Three-dimensional finite element analysis method can exactly reflect the comprehensive effect of complex stress state due to generating fold point and arching. [Pg.386]

Modeling is the method of choice for analyzing passenger car cord-reinforced rubber composite behavior. Large scale three-dimensional finite element analysis (FEIA) improves imderstanding of tire performance, including tire and tread behavior when the rubber meets the road. ... [Pg.226]

Murmane, R.A. Johnson, W.W. Moreland, N.J. The analysis of glass melting processes using three-dimensional finite elements. International journal for numerical methods in fluids, Vol 8, 1491-1511, 1988. [Pg.248]

Chen YH, Im YT, Lee ZH (1991) Three dimensional finite element analysis with phase change by temperature recovery method. Int J Mach Tools Manuf 31 1, Li BQ (1997) Numerical simulation of flow and temperature evolution during the initial phase of steady-state solidification. J Mater Process Technol 71 402-413... [Pg.372]

The AUGUR information on defect configuration is used to develop the three-dimensional solid model of damaged pipeline weldment by the use of geometry editor. The editor options provide by easy way creation and changing of the solid model. This model is used for fracture analysis by finite element method with appropriate cross-section stress distribution and external loads. [Pg.196]

Elliptic Equations Elhptic equations can be solved with both finite difference and finite element methods. One-dimensional elhptic problems are two-point boundary value problems. Two- and three-dimensional elliptic problems are often solved with iterative methods when the finite difference method is used and direct methods when the finite element method is used. So there are two aspects to consider howthe equations are discretized to form sets of algebraic equations and howthe algebraic equations are then solved. [Pg.480]

In reality, heat is conducted in all three spatial dimensions. While specific building simulation codes can model the transient and steady-state two-dimensional temperature distribution in building structures using finite-difference or finite-elements methods, conduction is normally modeled one-... [Pg.1066]

In the finite element method, Petrov-Galerkin methods are used to minimize the unphysical oscillations. The Petrov-Galerkin method essentially adds a small amount of diffusion in the flow direction to smooth the unphysical oscillations. The amount of diffusion is usually proportional to Ax so that it becomes negligible as the mesh size is reduced. The value of the Petrov-Galerkin method lies in being able to obtain a smooth solution when the mesh size is large, so that the computation is feasible. This is not so crucial in one-dimensional problems, but it is essential in two- and three-dimensional problems and purely hyperbolic problems. [Pg.58]


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