scholarly journals Methodology for predicting oily mixture properties in the mathematical modeling of molecular distillation

2017 ◽  
Vol 68 (2) ◽  
pp. 193 ◽  
Author(s):  
M. F. Gayol ◽  
M. C. Pramparo ◽  
S. M. Miró Erdmann

A methodology for predicting the thermodynamic and transport properties of a multi-component oily mixture, in which the different mixture components are grouped into a small number of pseudo components is shown. This prediction of properties is used in the mathematical modeling of molecular distillation, which consists of a system of differential equations in partial derivatives, according to the principles of the Transport Phenomena and is solved by an implicit finite difference method using a computer code. The mathematical model was validated with experimental data, specifically the molecular distillation of a deodorizer distillate (DD) of sunflower oil. The results obtained were satisfactory, with errors less than 10% with respect to the experimental data in a temperature range in which it is possible to apply the proposed method.

Author(s):  
Oleksandr Dzevochko ◽  
Mykhaylo Podustov ◽  
Alona Dzevochko ◽  
Vladimir Panasenko

The processes that occur in film absorbers during the sulfation of two-component mixtures of organic substances are quite complex and require mathematical modeling. This paper reports the construction of a mathematical model that makes it possible to adequately describe the process of sulfation involving gaseous sulfur trioxide in the production of surfactants. Based on the model, it became possible to investigate this process for higher alcohols of fractions С12–С14 and monoethanolamides of higher fatty acids of coconut oil. The data are given on the comparison of mathematical modeling results based on the mathematical model built with known experimental data and results of alternative mathematical modeling for different ratios of the length of the reaction pipe to its diameter (l/d). It is shown that the error in comparing the experimental data was 4.8–9.6 % at l l/d=29; 1.1–8.7 % at l/d=70; 3.9–12.3 % at l/d=144. The error in comparing known results of alternative mathematical modeling was, respectively, 6.3–7.2 %, 0.1–6.5 %, 0–1.0 %. These results were obtained for the molar ratio in the range of 1.0–1.15 and the SO3 concentration in the stream of 4.0–6.0 %. Such findings suggest that the established dependences of the basic parameters for the sulfation process are adequate in terms of the absorber length and its radial direction. Therefore, the mathematical model built does hold within the considered ranges of input variables. Consequently, it could be used in the theoretical study of the process of sulfation of two-component mixtures of organic substances by gaseous sulfur trioxide in a film absorber with a downward flow of phases. The results obtained could be used in practice, in particular in the manufacture of high-quality products for the cosmetic industry.


2020 ◽  
pp. 44-49
Author(s):  
V. V. Kharlamov ◽  
◽  
D. I. Popov ◽  
P. S. Sokolov ◽  
L. E. Serkova ◽  
...  

The article presents the results of comparison of experimental studies and mathematical modeling of the stand for testing induction motors by the method of mutual load. A detailed description of the composition of the experimental equipment, which is based on a pair of frequency converters and connected to them a pair of engines of the АИС71В4 type with a nominal power of 0,75 kW, the shafts of which are rigidly connected by a coupling. The mathematical model of the electromechanical system used in the calculations is presented, and its main assumptions are listed. A table of parameter values and graphs obtained from calculated and experimental data are presented. The analysis of the obtained data shows the possibility of using the considered mathematical model with the existing assumptions in the design of electrical complexes intended for testing induction motors by the method of mutual load


Author(s):  
Ērika Teirumnieka ◽  
Ilmārs Kangro ◽  
Edmunds Teirumnieks ◽  
Harijs Kalis ◽  
Aigars Gedroics

Bogs have been formed by an accumulation of peat - a light brown-to-black organic material, built up from partial decomposition of mosses and other bryophytes, sedges, grasses, shrubs, or trees under waterlogged conditions. The total peatlands area in Latvia covers 698 918 ha or 10.7% of the entire territory. Knowledge’s of peat metals content are important for any kind of peat using. Experimental determination of metals in peat is very long and expensive work. Using experimental data mathematical model for calculation of concentrations of metals in different points for different layers can help to very easy and fast to find approximately concentration of metals or trace elements. The results of the research show that concentrations of trace elements in peat are generally low. Concentrations differ between the superficial, middle and bottom peat layers, but the significance decreases depending on the type of mire. The mathematical model for calculation of concentration of metals in different points for different 3 layers in peat blocks is developed. As an example, mathematical models for calculation of Ca and Fe concentrations have been analyzed.


Volume 3 ◽  
2004 ◽  
Author(s):  
Janez Gale ◽  
Iztok Tiselj

The paper presents results of the 1D computer code WAHA, developed for the water hammer simulations, applied for the simulation of the critical flashing flow in the “Super Moby Dick” convergent-divergent nozzle. The mathematical model of the code is briefly introduced with special emphasis on applied dispersed flow homogeneous-relaxation model of inter-phase heat and mass transfer. The results of the simulations of the critical flashing flow are compared to the experimental data.


2003 ◽  
Vol 7 (3) ◽  
pp. 533-538 ◽  
Author(s):  
Mariângela Amendola ◽  
Anderson L. de Souza ◽  
Denis M. Roston

The aim of this research was to use experimental planning to collect data and also to establish a methodology to compare them with theoretical data, where both are associated to the dynamics of reduction in pollutants in a natural treatment system for wastewater. The experimental data were collected and evaluated from two of these systems, built according to Valentim & Amendola (1999) and Collaço (2001), at the Center of Mechanization and Agricultural Automation of the Agricultural Institute of Campinas, located in Jundiaí, SP, Brazil. These systems were rectangular in shape; one with crushed stone and another with chopped tires used as support bed to hold the plants, both with macrophyte species Typha sp. The theoretical data were obtained from a mathematical model, adapted to describe the physical process of subsurface flow. The numerical simulations using the implicit finite difference numerical method were carried out using MATLAB 6.1 software. The results of the comparative analysis between theoretical and experimental data are presented for the two types of support beds. Some coefficients and parameters were adjusted to characterize the constructed systems. The results obtained were analyzed and some conclusions about the physical process as well as those about the adequacy of the mathematical model were made.


2012 ◽  
Vol 19 (6) ◽  
pp. 1359-1372 ◽  
Author(s):  
R.R. Aguiar ◽  
H.I. Weber

The purpose of this work is the experimental investigation and the mathematical modeling of the impact force behavior in a vibro-impact system, where an impact pendulum is mounted on a cart that moves with a prescribed displacement. The dynamics of the system will be evaluated considering different excitation frequencies and changing the impact gap. Experimental data are used to validate the mathematical model. The mathematical model allows a detailed nonlinear analysis, showing the rich response of the system, which includes dynamical jumps, bifurcations and chaos. In impact systems, discrepancies between numerical results and experimental measurements are common due to the difficulty in describing all factors that influence the resulting impact force profile. The use of wires to suspend the impacting body has the purpose to limit these uncertainties.


1999 ◽  
Author(s):  
Mahmut D. Mat ◽  
Yüksel Kaplan ◽  
Olusegun J. Ilegbusi

Abstract Subcooled boiling of water in a vertical pipe is numerically investigated. The mathematical model involves solution of transport equations for vapor and liquid phase separately. Turbulence model considers the turbulence production and dissipation by the motion of the bubbles. The radial and axial void fractions, temperature and velocity profiles in the pipe are calculated. The estimated results are compared to experimental data available in the literature. It is found that while present study satisfactorily agrees with experimental data in the literature, it improves the prediction at lower void fractions.


2021 ◽  
Vol 316 ◽  
pp. 661-666
Author(s):  
Nataliya V. Mokrova

Current cobalt processing practices are described. This article discusses the advantages of the group argument accounting method for mathematical modeling of the leaching process of cobalt solutions. Identification of the mathematical model of the cascade of reactors of cobalt-producing is presented. Group method of data handling is allowing: to eliminate the need to calculate quantities of chemical kinetics; to get the opportunity to take into account the results of mixed experiments; to exclude the influence of random interference on the simulation results. The proposed model confirms the capabilities of the group method of data handling for describing multistage processes.


Author(s):  
Sudhakar Yadav ◽  
Vivek Kumar

This study develops a mathematical model for describing the dynamics of the banana-nematodes and its pest detection method to help banana farmers. Two criteria: the mathematical model and the type of nematodes pest control system are discussed. The sensitivity analysis, local stability, global stability, and the dynamic behavior of the mathematical model are performed. Further, we also develop and discuss the optimal control mathematical model. This mathematical model represents various modes of management, including the initial release of infected predators as well as the destroying of nematodes. The theoretical results are shown and verified by numerical simulations.


Author(s):  
A I Ryazanov

This paper describes the aerohydrodvnamics of processes in chambers of Gorlov's hydro-pneumatic power system. The mathematical model is developed to determine the main parameters of the processes: water and air velocities, air pressure in the chamber, the periods of time required to fill and empty the chambers and the output of energy during the cycle. The results obtained are in agreement with experimental data and model tests.


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