Software Framework UG: Parallel Simulation of a Three-Dimensional Benchmark Problem for Thermohaline-Driven Flow

2011 ◽  
pp. 553-560
Author(s):  
Michael Lampe ◽  
Alfio Grillo ◽  
Gabriel Wittum
Keyword(s):  
Three Dimensional ◽  
Parallel Simulation ◽  
Software Framework ◽  
Benchmark Problem

Consistent Tangent Stiffness of a Three-Dimensional Wheel–Rail Interaction Element

2021 ◽  
Author(s):  
Quan Gu ◽  
Jinghao Pan ◽  
Yongdou Liu
Keyword(s):  
Finite Element ◽  
Quadratic Convergence ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Light Rail ◽  
Software Framework ◽  
Tangent Stiffness ◽  
Rail Vehicle ◽  
Interaction Element ◽  
Nonlinear Equations Of Motion

Consistent tangent stiffness plays a crucial role in delivering a quadratic rate of convergence when using Newton’s method in solving nonlinear equations of motion. In this paper, consistent tangent stiffness is derived for a three-dimensional (3D) wheel–rail interaction element (WRI element for short) originally developed by the authors and co-workers. The algorithm has been implemented in finite element (FE) software framework (OpenSees in this paper) and proven to be effective. Application examples of wheelset and light rail vehicle are provided to validate the consistent tangent stiffness. The quadratic convergence rate is verified. The speeds of calculation are compared between the use of consistent tangent stiffness and the tangent by perturbation method. The results demonstrate the improved computational efficiency of WRI element when consistent tangent stiffness is used.

Advances in FEMN: The Code for Nuclear Noise Analysis Based on ICEM-CFD

2018 ◽  
Author(s):  
Baoxin Yuan ◽  
Herong Zeng ◽  
Wankui Yang ◽  
Songbao Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geometric Modeling ◽  
Noise Analysis ◽  
Three Dimensional ◽  
Noise Spectrum ◽  
Benchmark Problem ◽  
Reactor Physics ◽  
Icem Cfd ◽  
Element Method

The finite element method based on unstructured mesh has good geometry adaptability, it has been used to solve reactor physics problems, manual description of geometric modeling and meshing makes the current finite element code very complicated, it greatly restricts the application of this method in the numerical calculation of reactor physics. Using the CAD pre-processing software ICEM-CFD, three dimensional geometry is divided into tetrahedral or hexahedral meshes, two dimensional geometry is divided into triangular or quadrilateral meshes, the main code of neutron calculation for nuclear noise analysis based on finite element method is developed. The steady state parameters are calculated and tested through benchmark problem, the test results show that the code has the corresponding computing capabilities. Finally, the neutron noise spectrum is calculated for the 3D PWR benchmark problem published by IAEA, and the noise distribution under given frequency is given.

scholarly journals Binocular stereovision omnidirectional motion handling robot

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142092685
Author(s):  
Bo Tang ◽  
Li Jiang
Keyword(s):  
Real Time ◽  
High Efficiency ◽  
Recognition Rate ◽  
Three Dimensional ◽  
Image Feature ◽  
Software Framework ◽  
Matching Algorithm ◽  
Speeded Up Robust Features ◽  
Binocular Stereovision ◽  
The Relationship

Binocular stereovision has become one of the development trends of machine vision and has been widely used in robot recognition and positioning. However, the current research on omnidirectional motion handling robots at home and abroad is too limited, and many problems cannot be solved well, such as single operating systems, complex algorithms, and low recognition rates. To make a high-efficiency handling robot with high recognition rate, this article studies the problem of robot image feature extraction and matching and proposes an improved speeded up robust features (SURF) algorithm that combines the advantages of both SURF and Binary Robust Independent Elementary Features. The algorithm greatly simplifies the complexity of the algorithm. Experiments show that the improved algorithm greatly improves the speed of matching and ensures the real-time and robustness of the algorithm. In this article, the problem of positioning the target workpiece of the robot is studied. The three-dimensional (3-D) reconstruction of the target workpiece position is performed to obtain the 3-D coordinates of the target workpiece position, thereby completing the positioning work. This article designs a software framework for real-time 3-D object reconstruction. A Bayesian-based matching algorithm combined with Delaunay triangulation is used to obtain the relationship between supported and nonsupported points, and 3-D reconstruction of target objects from sparse to dense matches is achieved.

An Exploratory Framework for Combining CFD Analysis and Evolutionary Optimization Into a Single Integrated Computational Environment

2011 ◽  
Author(s):  
Douglas S. McCorkle ◽  
Kenneth M. Bryden
Keyword(s):  
Programming Languages ◽  
Transport System ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Software Framework ◽  
Computational Engineering ◽  
Geometric Models ◽  
Computational Environment ◽  
Computational Fluid Dynamics Cfd ◽  
High Level

Several recent reports and workshops have identified integrated computational engineering as an emerging technology with the potential to transform engineering design. The goal is to integrate geometric models, analyses, simulations, optimization and decision-making tools, and all other aspects of the engineering process into a shared, interactive computer-generated environment that facilitates multidisciplinary and collaborative engineering. While integrated computational engineering environments can be constructed from scratch with high-level programming languages, the complexity of these proposed environments makes this type of approach prohibitively slow and expensive. Rather, a high-level software framework is needed to provide the user with the capability to construct an application in an intuitive manner using existing models and engineering tools with minimal programming. In this paper, we present an exploratory open source software framework that can be used to integrate the geometric models, computational fluid dynamics (CFD), and optimization tools needed for shape optimization of complex systems. This framework is demonstrated using the multiphase flow analysis of a complete coal transport system for an 800 MW pulverized coal power station. The framework uses engineering objects and three-dimensional visualization to enable the user to interactively design and optimize the performance of the coal transport system.

PARALLEL SIMULATION OF EXPLOSION IN AN UNLIMITED ATMOSPHERE

2010 ◽  
Vol 24 (13) ◽  
pp. 1349-1352 ◽  
Author(s):  
TIANBAO MA ◽  
CHENG WANG ◽  
GUANGLEI FEI ◽  
JIANGUO NING
Keyword(s):  
Numerical Simulation ◽  
Parallel Algorithm ◽  
Large Scale ◽  
Three Dimensional ◽  
Parallel Simulation ◽  
Data Dependency ◽  
Empirical Results ◽  
Parallel Speedup ◽  
Good Agreement ◽  
Impact Problem

In this paper, a parallel Eulerian hydrocode for the simulation of large scale complicated explosion and impact problem is developed. The data dependency in the parallel algorithm is studied in particular. As a test, the three dimensional numerical simulation of the explosion field in an unlimited atmosphere is performed. The numerical results are in good agreement with the empirical results, indicating that the proposed parallel algorithm in this paper is valid. Finally, the parallel speedup and parallel efficiency under different dividing domain areas are analyzed.

scholarly journals A Simple Benchmark Problem for the Numerical Methods of the Cahn–Hilliard Equation

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yibao Li ◽  
Chaeyoung Lee ◽  
Jian Wang ◽  
Sungha Yoon ◽  
Jintae Park ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Convergence Rates ◽  
Temporal Integration ◽  
Three Dimensional ◽  
Problem Solution ◽  
Benchmark Problem ◽  
Runge Kutta Method ◽  
Cahn Hilliard Equation ◽  
The One ◽  
Nicolson Scheme

We present a very simple benchmark problem for the numerical methods of the Cahn–Hilliard (CH) equation. For the benchmark problem, we consider a cosine function as the initial condition. The periodic sinusoidal profile satisfies both the homogeneous and periodic boundary conditions. The strength of the proposed problem is that it is simpler than the previous works. For the benchmark numerical solution of the CH equation, we use a fourth-order Runge–Kutta method (RK4) for the temporal integration and a centered finite difference scheme for the spatial differential operator. Using the proposed benchmark problem solution, we perform the convergence tests for an unconditionally gradient stable scheme via linear convex splitting proposed by Eyre and the Crank–Nicolson scheme. We obtain the expected convergence rates in time for the numerical schemes for the one-, two-, and three-dimensional CH equations.

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