Papers by Keyword: Computer Modeling

Abstract: The main objective of this study is to optimize the reverse osmosis process in order to ensure the potabilization of water from the Oued Oum Er-Rbia, by determining the most influential parameters. To the best of our knowledge, this is the first study to apply daily PCA-based monitoring on Oued Oum Er-Rbia’s raw water to optimize membrane operation under Moroccan field conditions.To better understand the interactions between quality and hydraulic parameters influencing membrane performance, data were collected from Oued Oum Er-Rbia over multiple seasons. The parameters monitored included turbidity, salinity, temperature, and Silt Density Index (SDI), all known to affect fouling and pretreatment requirements.

Abstract: Currently, mathematical modeling applying numerical methods is widely used in the study of metallurgical processes, including metal casting processes in continuous-casting machines. The authors developed a new technology and device for casting metal into a continuous-casting machine mold and metal mixing using the effect of a rotating closed-bottom submerged nozzle with eccentric holes. The theoretical study of processes of mold filling with molten metal was carried out applying a proven numerical method and a special software package. A calculation program was developed based on the numerical schemes and algorithms. The results of calculating metal casting into a rectangular mold are presented as an example. The calculation results are provided in the form of molten metal flow patterns in various sections of the mold.

Abstract: The present article discusses the cylindrical mandrel wear change during rolling using MISIS - 130 D mill depending on the type of rolled billets materials used. The research on the mandrel wear of the screw rolling mill during pipes elongation was carried out using the finite element method (FEM). The results of the wear modeling showed that the depth of the metal removed on the mandrel surface during stainless steel pipes elongation was higher as compared to alloyed and carbon steel pipes. The significant wear of the mandrel during stainless steel pipe rolling can be explained by the rise in the applied metal force resulting from the introduction of alloying components such as chromium and nickel into rolled billets materials. Consequently, the obtained modeling results can allow predicting the service life of working tools.

Abstract: Modern continuous mills FQM are high-performance technological units that allow you to get products of a wide range. The paper presents the results of the study of the effect of the time of holding the mandrel in the extreme position of the continuous mill FQM (Fine Quality Mill) on the probability of defect formation of surface defects. The problems of сcomputational simulation of the process of continuous rolling of pipes were set and solved. It is established that the increase in the holding time of the mandrel allows to reduce the sliding of the metal on the surface of the tool, and contributes to a stable process of removing the mandrel without the formation of defects on the inner surface of the draft pipe. The results of solving the problems of сcomputational modeling allowed to formulate technical recommendations aimed at reducing the probability of surface defects in the production of pipes at the FQM mill.

Abstract: The paper deals with the problems and prospects of forming thin-sheet blanks, using ABS plastic dies, made by 3D printing. This technology combines the positive properties of plastic material and 3D-printing. The mechanical characteristics of the plastic were determined experimentally. On the basis of computer modeling, the dependence between the angle of bending the blank and the stresses arising in the dies is established. As a result of computer simulation and physical experiment, the value of the maximum thickness 0.5 mm for the aluminum 3003 blank is obtained. In this case, there is no plastic deformation of the plastic tool. The use of plastic dies does not require lubrication. The technology of sheet bending, using a plastic tool, can be implemented with the greatest efficiency in single and small-scale production.

Abstract: Aiming the development of novel composites reinforced with natural fibers from vegetable origin, it is important the understanding and control of processing parameters in twin-screw extruders. The temperature profile and the screw components, as well as the extrusion speed, compromise the distribution and dispersion of the fibers in the matrix and consequently in their rheological behavior, which reflects in the mechanical, chemical and morphological properties of the composites and products obtained from them. One new tool, used to understand processing parameters in composites, is computer simulation. In this study, we used the WinTXS Software to evaluate the influence of process parameters in the polypropylene matrix composite reinforced with 30 vol% wood flour. Parameters such as shear rate, temperature, melt viscosity, and viscous dissipation were evaluated. It was observed that increasing screw speed, the temperature increased, which results from the viscous dissipation. Under these conditions, the shear rate and melt viscosity were reduced.

Abstract: A series of computer experiments using the molecular dynamics method, imitating the processes of the argon particles system cooling at different cooling rates, was carried out. As a result of modeling, solid phases of varying degrees of order were obtained, a comparative analysis of structures was performed using the calculation of the radial distribution functions of particles and using the author’s algorithm for recognizing clusters of a crystal structure.

Abstract: The paper proposes a mathematical model of the formation of a deep-hole cut when boring it; substantiates that the cut is manifested as the technological heredity of the errors of the workpiece; confirms theoretical positions by using the method of computer simulation of the process of shaping during the finishing boring of the deep holes of hydraulic-cylinder barrels made of various steels; and introduces design and technological methods for minimizing hole errors.

Abstract: The problem state of computer analysis of shrinkage defects in castings is analysed based on a review of theoretical and experimental studies the filtration permeability of solidifying alloys. It is shown that the use of the dimensionless permeability coefficient and its modification by introducing various corrections to the Karman-Kozeni equation, obtained for the stationary morphology of non-intersecting filtration channels, is inapplicable for the conditions of continuous change of their geometry during formation of dendrite structure. A computer model of the permeability for the mesoscale ensemble of secondary dendritic branches under the conditions of their diffusion-capillary coalescence is developed. Based on the thermodynamic apparatus and solidification modeling the influence of composition of Al-Cu-Mg alloys and heat removal velocity on the permeability coefficient under the evolution of the dendritic structure is analysed.

Abstract: This article deals with studying the technology of electric arc spraying of the eccentric body by selection of the copper-steel pseudo-alloy for spraying a covering. The part durability with the placed covering depends on the technology of spraying and the properties of the sprayed material. By increasing the strength of adhesion of the covering to the base it is possible to establish the optimal indicators of the coating mode. It became the main criterion of studying the arc spraying technology from the mathematical point of view.