Development Of Numerical Simulation Model Research Articles

A Review of Biomass Thermal Analysis, Kinetics and Product Distribution for Combustion Modeling: From the Micro to Macro Perspective

Driven by its accessibility, extensive availability, and growing environmental consciousness, solid biomass has emerged as a viable alternative to enhance the diversity of renewable energy sources for electricity generation. To understand the phenomena involved in solid biomass conversion, it is necessary not only to understand the stages of the biomass combustion process but also to understand specifically the kinetics of the reaction and the release of the volatiles. The present work presents an overview of the existing literature on several topics related to the biomass combustion process, its characterization, as well as strategies to develop simple and effective models to describe biomass conversion with a view to the future development of numerical simulation models. Since the focus of most of the investigations is the development of a numerical model, a summary and identification of the different model assumptions and problems involved in thermal analysis experiments are presented. This literature review establishes the significance and credibility of the research, providing the main concepts and assumptions with a critique on their validity. Hence, this work provides specific contributions from a multi-scale perspective which can further be extended to provide insights into the design and optimization of biomass combustion technologies, such as boilers and furnaces.

Techniques for correlation of drop weight impact testing and numerical simulation for composite GFRP crash boxes using Ls-Dyna

Composite materials are being widely used in automobile industry in order to meet the ever increasing demand to achieve significant weight reduction by maintaining the performance levels. Additionally, there are a number of challenging crashworthiness criteria set by the regulating authorities in various countries for vehicle safety, which the vehicle has to qualify. In these cases composites can be very useful as they exhibit high strength to weight ratios. But, deformation modes of composites are more complex when compared to metals, due to which it is more important to analyse the behaviour of composites under impact. In this study four types of cross sections (square, cylindrical, hexagonal and decagonal) were considered for the geometric shapes of GFRP (glass fiber reinforced plastic) crash boxes. Drop weight impact testing is widely used for studying the behaviour of parts subjected to impact loadings. The drop weight impact testing is highly dynamic in nature and in addition various factors like data acquisition signal noise (disturbance) requires the user to test 3–4 samples for each test specimen, for repeatability and minimisation of errors, which thereby increases the total number of testing samples. Therefore, in practise only a limited number of specimens can be actually tested using drop weight impact test considering the number of specimen samples to be manufactured and the cost involved in it. In this paper the development of numerical simulation model for drop weight impact test and its correlation with the real time drop weight impact testing was discussed in detail. *PART_COMPOSITE model along with *MAT58 material card was used for laminated GFRP composite specimen in Ls-Dyna along with calibration of parameters like longitudinal compression stress limiting factor (SLIMC1) and softness factor (SOFT) for simulation. The numerical simulation was correlated with the experimental data using correlation factors. The deformation modes as well as the F-D (force versus displacement) curves and SEA (specific energy absorption) values were found to have a close match between experiments and finite element simulations.

Development of Numerical Simulation Models for Oxide Film and Air Inclusion Defects Using SPH Method and its Applications

Development of Numerical Simulation Models for Oxide Film and Air Inclusion Defects Using SPH Method and its Applications

固気二相流の離散粒子シミュレーションの進展

The development of numerical simulation models and methods in gas-solid two-phase flows by the author' s group in the last three decades is briefly reviewed. Eulerian-Lagrangian coupling simulations have been largely developed, especially DEM-CFD coupling simulation has become popular, and widely used in many operations of powder technology field. The establishment of the Japan society for multiphase flow played a very important role in the development of DEM-CFD coupling model.

Computational Simulation of Ultraviolet ZnO Diode Laser

This article deals with a mathematical technique for the study of functionality of semiconductor laser, by its rate equations, to be used in the simulation of high speed optical systems. We describe the development of numerical simulation model of a p-ZnO laser emitting in UV optical wavelength. A powerful dynamic algorithmical model is used to study the p-ZnO active region waveguide laser. It is based on time dependant rate equations of a quasi two levels system for the population density and time dependant for the pump and optical signal power. The model is sufficient to account for many of the observed dynamics in a single mode semiconductor laser in response to a dynamic drive current, such as relaxation oscillations and frequency chirping.

Development of numerical simulation model for FSW employing particle method

The friction stir welding (FSW) has been used widely in the field of industry. Numerical analysis models for FSW also have been developed and there are many papers about it. In these papers, the most frequently used method is finite element method or finite difference method. However, by employing these methods, it is difficult or troublesome to calculate the advective term both for momentum and temperature. It is also difficult to calculate the big deformation of the material. Moreover, complex process is required to analyse the dissimilar joining with respect to dealing with substance transfer. In this paper, to avoid these difficulties or troublesome processes, particle method is adopted for dissimilar FSW simulation. In particle method, advective term, substance transfer and surface deformation are calculated automatically mainly because that Lagrangian approach is used. Performing some of analysis for FSW, the effectivity of this method is verified.

Numerical Magnetohydrodynamic (MHD) Modeling of Coronal Mass Ejections (CMEs)

The Coronal Mass Ejection (CME) is arguably the most important discovery of solar eruptive phenomena in the 20th century. It is now also recognized that CMEs have great impact on the Earth's environment by inducing geomagnetic storms. Thus, development of simulation models to understand the physical mechanisms of CME initiation and propagation has become a challenge in the solar MHD community. In this paper we shall summarize chronologically the development of the theoretical analyses, and the successes and failures of the numerical magnetohydrodynamic (MHD) simulations of coronal mass ejections (CMEs) during the past two decades. The chronological development of numerical simulation models and the evolution of the numerical methods to treat this class of problems are presented. The most appropriate way to model CMEs is to have (i) a realistic pre-event coronal atmosphere, and (ii) realistic driving mechanisms. Details of the progress and assessment of the theoretical and modeling efforts for the understanding of the physics of the CME initiation and propagation will be presented, and the numerical methods to construct these simulation models will be discussed.