Continuous Prediction Model of Carbon Content in 120 t Converter Blowing Process

A continuous prediction model of carbon content of 120 t BOF is established in this paper. Based on the three-stage decarburization theory and combined with the production process of 120 t converter, the effects of oxygen lance height and top blowing oxygen flow rate are also considered in the model. The explicit finite difference method is used to realize continuous prediction of carbon content in the converter blowing process. The model parameters such as ultimate carbon content in molten pool are calculated according to the actual data of 120 t BOF, which improves the hit rate of the model. Process verification and end-point verification for the continuous prediction model have been carried out, and the results of process verification indicate that the continuous prediction model established in the paper basically accords with the actual behavior of decarburization. Moreover, the hit ratio of the continuous prediction model reached 85% for the prediction of end-point carbon content within a tolerance of ±0.02%.

Numerical Study of Cylindrical Tropical Woods Pyrolysis Using Python Tool

In this paper, the thermal behavior of large pieces of wood pyrolysis has been modeled. Two mathematical models coupling heat transfer equations to chemical kinetics were used to predict the pyrolytic degradation of a 25 mm radius wood sample, assumed to be dry in the first model and wet in the second, when heated to 973.15 K. The reactions involved in the pyrolysis process are assumed to be endothermic. The diffusion of bounded water during the process is taken into account in the second model, where the heat transfer equation has been coupled to that of the diffusion of moisture. This model, although simple, provides more information on the drying and pyrolysis processes during the heating of wood, which is its originality. It can therefore be advantageously used to calculate the temperature distribution in a pyrolysis bed. The equations of the two models, discretized by an explicit finite difference method, were solved numerically by a program written in Python. The validation of both models against experimental work in the literature is satisfactory. The two models allow examination of the temperature profile in the radial direction of wood samples and highlighting of the effect of temperature on some thermal, physical and physicochemical characteristics.

Fast and Accurate Numerical Solution of Allen–Cahn Equation

Simulation speed depends on code structures. Hence, it is crucial how to build a fast algorithm. We solve the Allen–Cahn equation by an explicit finite difference method, so it requires grid calculations implemented by many for-loops in the simulation code. In terms of programming, many for-loops make the simulation speed slow. We propose a model architecture containing a pad and a convolution operation on the Allen–Cahn equation for fast computation while maintaining accuracy. Also, the GPU operation is used to boost up the speed more. In this way, the simulation of other differential equations can be improved. In this paper, various numerical simulations are conducted to confirm that the Allen–Cahn equation follows motion by mean curvature and phase separation in two-dimensional and three-dimensional spaces. Finally, we demonstrate that our algorithm is much faster than an unoptimized code and the CPU operation.

Modeling of Gust Energy Extractions through Aeroelastic Tailoring

A tightly coupled fluid-structure interaction model is presented for studying the performance of flexible wings that encounter atmospheric gusts. The aerodynamic module uses a higher-order potential flow method, that provides numerical robustness and efficiency. The structural dynamics is modelled through an explicit finite difference method of the time-depenedent Euler-Bernoulli equations. Coupled together, these approaches offer numerical accuracy at a fraction of the computational time than is required for higher fidelity approaches. Previous research has suggested energy gains are possible from atmospheric gusts through aeroelastic tailoring. Case studies were performed using the aeroelastic model to investigate the merit of using aeroelastic tailoring as a passive means for performance improvement. Design trends were established that highlight configurations that achieve the best energy extraction from a gust. Reductions in wing drag of between 6.9% and 10.5% were observed, while gains of 0.25% between different aeroelastic configurations were presented. The forward sweeping of the elastic axis was deemed to have the greatest effect on energy extraction capabilities.

Modeling of Gust Energy Extractions through Aeroelastic Tailoring

A tightly coupled fluid-structure interaction model is presented for studying the performance of flexible wings that encounter atmospheric gusts. The aerodynamic module uses a higher-order potential flow method, that provides numerical robustness and efficiency. The structural dynamics is modelled through an explicit finite difference method of the time-depenedent Euler-Bernoulli equations. Coupled together, these approaches offer numerical accuracy at a fraction of the computational time than is required for higher fidelity approaches. Previous research has suggested energy gains are possible from atmospheric gusts through aeroelastic tailoring. Case studies were performed using the aeroelastic model to investigate the merit of using aeroelastic tailoring as a passive means for performance improvement. Design trends were established that highlight configurations that achieve the best energy extraction from a gust. Reductions in wing drag of between 6.9% and 10.5% were observed, while gains of 0.25% between different aeroelastic configurations were presented. The forward sweeping of the elastic axis was deemed to have the greatest effect on energy extraction capabilities.

Optimization of Stabilizing Systems in Protection of Cultural Heritage: The Case of the Historical Retaining Wall in the Wisłoujście Fortress

The aim of the paper is to propose new quantitative criteria for selecting the optimal method of securing and repairing a historical object, which take into account Structural, Conservation and Architectural aspects (the S–C–A method). Construction works on cultural heritage sites tend to be challenging and require an interdisciplinary approach. Therefore, they are strictly related to the philosophy of sustainable development which seeks adequate proportions between factors indicated on the natural and social environment. Optimization of several systems stabilizing retaining structure that are a historic object was considered in the paper. Appropriate formulas for scores meeting additional conservation and aesthetic requirements were proposed. The method is used in the stabilization of the brick retaining wall, a part of the Wisłoujście Fortress located in Gdańsk, Poland. In order to compute the displacement of the wall and its stability, numerical analysis was performed by the two-dimensional explicit Finite Difference Method (using the FLAC2D software). The algorithm proposed could be beneficial to the protection of cultural heritage since it could also be applied to other structures, such as roof trusses, masonry walls, pillars, etc.

Super-Time-Stepping Scheme for Option Pricing

We solve the Black - Scholes equation for option pricing numerically using an Explicit finite difference method. To overcome the stability restriction of the explicit scheme for parabolic partial differential equations in the time step size Courant-Friedrichs-Lewy (CFL) condition, we employ a Super Time Stepping (STS) strategy based on modified Chebyshev polynomial. The numerical results show that the STS scheme boasts of large efficiency gains compared to the standard explicit Euler method.