[Smart Innovation, Systems and Technologies] Advances in Theory and Practice of Computational Mechanics Volume 173 (Proceedings of the 21st International Conference on Computational Mechanics and Modern Applied Software Systems) ||

This book discusses physical and mathematical models, numerical methods, computational algorithms and software complexes, which allow high-precision mathematical modeling in fluid, gas, and plasma mechanics; general mechanics; deformable solid mechanics; and strength, destruction and safety of structures. These proceedings focus on smart technologies and software systems that provide effective solutions to real-world problems in applied mechanics at various multi-scale levels. Highlighting the training of specialists for the aviation and space industry, it is a valuable resource for experts in the field of applied mathematics and mechanics, mathematical modeling and information technologies, as well as developers of smart applied software systems. Preface Contents About the Editors 1 Advances in Computational Mechanics and Numerical Simulation 1.1 Introduction 1.2 Chapters in the Book 1.3 Conclusions References Part I Computational Fluid Dynamics 2 The Splitting Scheme for Mathematical Modeling of the Mixed Region Dynamics in a Stratified Fluid 2.1 Introduction 2.2 Mathematical Model. Foundation of the Problem 2.3 Splitting Scheme 2.4 Finite-Difference Scheme 2.5 Results 2.6 Conclusions References 3 Modeling of Some Astrophysical Problems on Supercomputers Using Gas-Dynamic Model 3.1 Introduction 3.2 Mathematical Models of the Evolution of the Stellar Accretion Disk 3.3 Numerical Simulation of the Evolution of the Stellar Accretion Disk 3.3.1 Simulation of the Evolution of the External Area of Stellar Accretion Disk 3.3.2 Numerical Results of the Formation of Vortex Structures in Stellar Accretion Disks 3.4 Conclusions References 4 Numerical Modeling of the Kolmogorov Flow in a Viscous Media 4.1 Introduction 4.2 Description of the Experiment 4.3 Problem Statement and Numerical Method 4.3.1 Problem Statement 4.3.2 Numerical Method 4.4 Results 4.5 Conclusions References 5 On Structures of Supersonic Flow Around Plane System of Cylindrical Rods 5.1 Introduction 5.2 Formulation of Problem 5.3 Multiblock Computing Technology 5.4 Calculation Results for Lattice of 10 Elements 5.5 Calculation Results for Infinite Lattice with Periodical Conditions 5.6 Conclusions References 6 Limiting Functions Affecting the Accuracy of Numerical Solution Obtained by Discontinuous Galerkin Method 6.1 Introduction 6.2 Discontinuous Galerkin Method for Euler Equations 6.2.1 Cockburn Limiter 6.2.2 Moment Limiter 6.2.3 Limiter Based on WENO Reconstruction 6.2.4 Limiter Based on Averaging the Solution 6.2.5 Slope Limiter 6.3 Numerical Experiments 6.4 Conclusions References Part II Numerical Simulation of Multiphase Flows, Combustion, and Detonation 7 Numerical Simulation of Detonation Initiation: The Quest of Grid Resolution 7.1 Introduction 7.2 Problem Statement 7.3 Mathematical Model and Numerical Method 7.4 Technical Features 7.5 Numerical Experiments 7.6 Conclusions References 8 On the Stability of a Detonation Wave in a Channel of Variable Cross Section with Supersonic Input and Output Flows 8.1 Introduction 8.2 Mathematical Model 8.3 Testing 8.4 The Results of Mathematical Modeling 8.5 Conclusions References 9 Physical and Kinematic Processes Associated with Meteoroid When Falling in the Earth’s Atmosphere 9.1 Introduction 9.2 Heat Transfer to the Surface of Meteoroids 9.3 Fragmentation of Meteoroids 9.4 Thermal Stress 9.5 Conclusions References 10 Computational Modeling of Rarefied Plasma and Neutral Gas Effusion into Vacuum 10.1 Introduction 10.2 Physical, Mathematical, and Computational Models of the Problem 10.3 Methodical Calculations 10.4 Results of Computational Experiments 10.5 Conclusions References 11 Numerical Simulation of the Process of Phase Transitions in Gas-Dynamic Flows in Nozzles and Jets 11.1 Introduction 11.2 Mathematical Models 11.2.1 Method of Moments 11.2.2 Quasi-Chemical Model of Homogeneous Condensation 11.3 Numerical Results 11.3.1 Test: Ideal Constant Volume Adiabatic Reactor 11.3.2 Wet Steam Flow with Spontaneous Condensation in Laval Nozzle 11.4 Conclusions References 12 Numerical Study of the Injection Parameters Impact on the Efficiency of a Liquid Rocket Engine 12.1 Introduction 12.2 Features of the Working Process 12.3 The Studied Object 12.4 Numerical Modeling of the Processes in Combustion Chamber 12.5 Study of the Fuel Injection 12.6 Conclusions References Part III Computational Solid Mechanics 13 Methods for Calculating the Dynamics of Layered and Block Media with Nonlinear Contact Conditions 13.1 Introduction 13.2 Mathematical Model 13.3 Layered Model System of Equations 13.4 Block Model System of Equations 13.5 Numerical Method 13.6 Simulation Results 13.7 Conclusions References 14 Algorithms for Calculating Contact Problems in the Solid Dynamics 14.1 Introduction 14.2 Mathematical Model 14.3 Numerical Method 14.4 Use of Lagrange Multipliers 14.5 Using Penalty Functions 14.6 Examples 14.6.1 The Impact of Two Bodies at an Angle 14.6.2 Explosion Welding Problem 14.7 Conclusions References 15 Different Approaches for Solving Inverse Seismic Problems in Fractured Media 15.1 Introduction 15.2 Direct Seismic Problem Solution 15.3 Inverse Problem Solution 15.4 Conclusions References 16 Elastic Wave Scattering on a Gas-Filled Fracture Perpendicular to Plane P-Wave Front 16.1 Introduction 16.2 Problem Statement 16.3 Elastic Wave Patterns 16.4 Amplitudes of Private Solutions Components 16.5 Scattering Amplitudes and Angles 16.6 Conclusions References 17 Discrete Element Method Adopting Microstructure Information 17.1 Introduction 17.2 Multiscale Discrete Element Model 17.3 Computational Experiments 17.4 Conclusions References 18 Durability Evaluation of Bonded Repairs for the Damaged Metallic Structures Subjected to Mechanical and Thermal Loads 18.1 Introduction 18.2 Analytical Model of the Bonded Repair 18.2.1 Stage 1. Stress Computation for Bonded Joint Without Damage 18.2.2 Stage 2. Computation of Stress Intensity Factors in the Skin with Damage 18.3 Elastic Properties Degradation of the Repair Patch Material 18.3.1 Testing Procedure and Materials 18.3.2 Results of Fatigue Tests 18.3.3 Elastic Modulus Change Evaluation Based on Fatigue Test Data 18.4 Bonded Repair Effectiveness Calculation Results 18.5 Conclusions References 19 Parametric Identification of Tersoff Potential for Two-Component Materials 19.1 Introduction 19.2 Problem Statement 19.3 Comparison of Optimization Methods 19.4 Results 19.4.1 Silicon 19.4.2 Germanium 19.4.3 Aluminum Nitride 19.4.4 Boron Nitride 19.5 Description of Software 19.6 Conclusions References Part IV Numerical Study of Dynamic Systems 20 Multi-agent Optimization Algorithms for a Single Class of Optimal Deterministic Control Systems 20.1 Introduction 20.2 Description of Multi-agent Methods 20.2.1 Optimization Problem 20.2.2 Fish School Search Algorithm 20.2.3 Krill Herd Algorithm 20.2.4 Imperialist Competitive Algorithm 20.2.5 Hybrid Multi-agent Algorithm 20.3 Application of Multi-agent Methods for Optimal Open-Loop Control Problems 20.3.1 Statement of the Problem 20.3.2 Search Algorithm of Optimal Open-Loop Control 20.3.3 Software 20.3.4 Solving the Problem of Finding Optimal Open-Loop Control 20.4 Conclusions References 21 Spectral Method for Analysis of Diffusions and Jump Diffusions 21.1 Introduction 21.2 Spectral Method Formalism 21.2.1 Multidimensional Matrices 21.2.2 Spectral Characteristics of Functions and Linear Operators 21.3 Spectral Method for Analysis of Diffusions 21.3.1 Problem Statement 21.3.2 Spectral Method for Solving Fokker–Planck–Kolmogorov Equation 21.3.3 Dryden Wind Turbulence Model 21.4 Spectral Method for Analysis of Jump Diffusions 21.4.1 Problem Statement 21.4.2 Spectral Method for Solving Kolmogorov–Feller Equation 21.4.3 Dryden Wind Turbulence Model with Jumps 21.5 Conclusions References 22 Long-Period Lunar Perturbations in Earth Pole Oscillatory Process: Theory and Observations 22.1 Introduction 22.2 Mathematical Description of the Earth Pole Oscillatory Processes 22.2.1 Celestial-Mechanical Model of the Earth Pole Motion 22.2.2 Lunar–Solar Perturbations in the Model of Earth Pole Motion 22.2.3 Variations of the Geopotential Coefficients 22.3 Gravitational and Tidal Perturbations in the Model of the Earth Pole Motion 22.3.1 Gravitational-Tidal Lunar–Solar Moment of Forces 22.3.2 The Oscillatory Process of the Earth Pole at the Frequency of the Moon’s Orbit Precession 22.4 Conclusions References 23 Application of Modified Fireworks Algorithm for Multiobjective Optimization of Satellite Control Law 23.1 Introduction 23.2 Dynamic System Model 23.3 Sketch of Solution 23.4 Solution of Multiobjective Problem 23.4.1 Multiobjective Optimization Problem 23.4.2 Modification of Multiobjective Fireworks Algorithm 23.4.3 Algorithm 23.5 Numerical Experiments 23.6 Conclusions References 24 Approximate Filtering Methods in Continuous-Time Stochastic Systems 24.1 Introduction 24.2 Optimal Filtering Problem 24.3 Equations for Conditional Probability Density 24.4 Particle Filters 24.5 Conclusions References 25 Essentials of Fractal Programming 25.1 Introduction 25.2 The Elastic Object Model 25.3 Fractal Programming 25.3.1 The Model of Container–Component Elastic Objects 25.3.2 The Model of Architectural Elastic Objects 25.3.3 The Model of Fractal Petri Nets as Elastic Objects 25.4 Conclusions References