Optimization of the Navy’s three-dimensional mine impact burial prediction simulation model, Impact35, using high-order numerical methods

2021 ◽  
pp. 154851292110286
Author(s):  
Athanasios Donas ◽  
Ioannis Famelis ◽  
Peter C Chu ◽  
George Galanis
Keyword(s):  
Numerical Analysis ◽  
Numerical Methods ◽  
Prediction Model ◽  
Simulation Model ◽  
Three Dimensional ◽  
Simulation System ◽  
High Order ◽  
Alternative Methodology ◽  
Runge Kutta ◽  
Fifth Order

The aim of this paper is to present an application of high-order numerical analysis methods to a simulation system that models the movement of a cylindrical-shaped object (mine, projectile, etc.) in a marine environment and in general in fluids with important applications in Naval operations. More specifically, an alternative methodology is proposed for the dynamics of the Navy’s three-dimensional mine impact burial prediction model, Impact35/vortex, based on the Dormand–Prince Runge–Kutta fifth-order and the singly diagonally implicit Runge–Kutta fifth-order methods. The main aim is to improve the time efficiency of the system, while keeping the deviation levels of the final results, derived from the standard and the proposed methodology, low.

Development of Three-Dimensional Neutron Kinetics Code Based on High Order Nodal Expansion Method in Hexagonal-Z Geometry

2018 ◽  
Author(s):  
Guo Chao ◽  
Liu Yu ◽  
He Hangxing ◽  
Liu Luguo ◽  
Wang Xiaoyu ◽  
...  
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Expansion Method ◽  
High Order ◽  
Benchmark Problems ◽  
Weighting Method ◽  
Control Rod ◽  
Order Polynomial ◽  
Runge Kutta ◽  
Nodal Expansion Method

To solve three-dimensional kinetics problems, a high order nodal expansion method for hexagonal-z geometry (HONEM) and a Runge-Kutta (RK) method are respectively adopted to deal with the spatial and temporal problem. In the HONEM, 1D partially-integrated flux are approximated by using four order polynomial. The two order polynomial is adopted to the approximation of partially-integrated leakages. The Runge-Kutta method is adopted as a tool for dispersing the time term of 3D kinetics equation. A flux weighting method (FWM) is used for obtaining homogenized cross sections of mix node. The three-dimensional hexagonal kinetics code has been developed based on this method and tested with two benchmark problems of VVER which are the control rod ejection without any feedback and with simple adiabatic Doppler feedback. The results calculated by this code agree well with the reference results and the code is validated.

Three-Dimensional Dynamic Simulation System for Forest Surface Fire Spreading Prediction

2018 ◽  
Vol 32 (08) ◽  
pp. 1850026 ◽  
Author(s):  
Jianwei Li ◽  
Xiaowen Li ◽  
Chongchen Chen ◽  
Huiru Zheng ◽  
Naiyuan Liu
Keyword(s):  
Prediction Model ◽  
Forest Fire ◽  
Forest Fires ◽  
Large Scale ◽  
Three Dimensional ◽  
Simulation System ◽  
Dynamic Visualization ◽  
Surface Fire ◽  
Fire Spreading ◽  
The Impact

Forest fire is one of the most frequent, fast spreading and destructive natural disasters. Many countries have developed their own fire prediction model and computational systems to predict the fire spreading, however, the user interaction, display effect and prediction accuracy have not yet met the requirements for firefighting in real forest fire events. The forest fire spreading is a complex process affected by multi-factors. Understanding the relationships between these multi-factors and the forest fire spreading trend is vital to predicting the fire spreading promptly and accurately to make the strategy in extinguishing the forest fire. In this paper, we propose and develop a three-dimensional (3D) forest fire spreading simulation system, FFSimulator, to visualize the impact of multi-factors to the fire spread. FFSimultor integrates the multi-factor analysis approach with the FARSITE prediction model to improve the prediction. The FFSimulator developed applies 3D scene organization, template-based vector data mapping and overlaps visualization techniques to provide a 3D dynamic visualization of large-scale forest fire. The 3D multi-factors superposition analysis simulates the impacts of individual factor and multi-factors on the trend of surface fire spreading, which can be used to identify the key sites for the prevention and the control of forest fires. The system has been tested and evaluated using real data of Shanghan forest fire.

scholarly journals Application of Numerical Methods for the Analysis of Damped Parallel RLC Circuit

2021 ◽  
Vol 26 (1) ◽  
pp. 28-34
Author(s):  
J. Kafle ◽  
B. K. Thakur ◽  
I. B. Bhandari
Keyword(s):  
Numerical Methods ◽  
Numerical Solutions ◽  
Numerical Technique ◽  
Euler Method ◽  
Numerical Solution Methods ◽  
Rlc Circuit ◽  
Solution Methods ◽  
Series Configuration ◽  
Runge Kutta ◽  
Fifth Order

A sudden application of sources results in time-varying currents and voltages in the circuit known as transients. This phenomenon occurs frequently during switching. A simple circuit constituting a resistor, an inductor, and a capacitor is termed an RLC circuit. It may be in parallel or series configuration or both. Different values of damping factors determine the different nature of the transient response. We applied different numerical solution methods such as explicit (forward) Euler method, third-order Runge-Kutta (RK3) method, and Butcher's fifth-order Runge-Kutta (BRK5) method to approximate the solution of second-order differential equation with initial value problem (IVP). We thoroughly compared the numerical solutions obtained by these methods with the necessary visualization and analysis of error. We also examined the superiority of these methods over one another and the appropriateness of numerical methods for different damping conditions is explored. With high accuracy of the approximation and thorough analysis of the observation, we found Butcher's fifth-order Runge-Kutta (BRK5) method to be the best numerical technique. Regarding the different values of damping factors, we considered the further possibility of discussion and analysis of this iterative method.

Runge-Kutta Discontinuous Galerkin Method Using Weno-Type Limiters: Three-Dimensional Unstructured Meshes

2012 ◽  
Vol 11 (3) ◽  
pp. 985-1005 ◽  
Author(s):  
Jun Zhu ◽  
Jianxian Qiu
Keyword(s):  
Discontinuous Galerkin ◽  
Hyperbolic Conservation Laws ◽  
Three Dimensional ◽  
Unstructured Meshes ◽  
Finite Volume Methods ◽  
High Order ◽  
High Order Accuracy ◽  
Hyperbolic Conservation ◽  
Runge Kutta ◽  
Nonlinear Hyperbolic Conservation Laws

AbstractThis paper further considers weighted essentially non-oscillatory (WENO) and Hermite weighted essentially non-oscillatory (HWENO) finite volume methods as limiters for Runge-Kutta discontinuous Galerkin (RKDG) methods to solve problems involving nonlinear hyperbolic conservation laws. The application discussed here is the solution of 3-D problems on unstructured meshes. Our numerical tests again demonstrate this is a robust and high order limiting procedure, which simultaneously achieves high order accuracy and sharp non-oscillatory shock transitions.

Upon Impact Numerical Modeling of Foam Materials

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Boundary Conditions ◽  
General Character ◽  
Foam Material ◽  
Various Boundary Conditions ◽  
Specific Behaviour

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.

Sign in / Sign up

Export Citation Format

Share Document