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1

The peculiarities of applying CAD/CAE systems for the primary combustion chamber flame tube cycle life prolongation of the tactical military aircraft afterburning turbofan jet engine

Pashchenko Serhii, Kharchenko Oleksandr, Shulhin Artem, Chemerys Yevheniy

Journal of KONBiN

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2022

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Vol. 52, iss. 4

167--176

EN

In this article, the computational simulation of the workflow in the primary combustion chamber flame tube of the afterburning turbofan jet engine (ATJE) on the tactical military aircraft was carried out. The geometric model of a flame tube was created and adapted to perform the interrelated calculation of the thermal and stress-strain behaviour of the walls of the flame tube influenced by the operational loads during the computational simulation of the workflow. Quantitative and qualitative analysis of the simulation results was conducted, and the connection between the peculiarities of the workflow and the characteristic damage of the flame tubes, detected during the operation, was established. The possibility of using modern CAD/CAE systems to solve the scientific tasks towards maximizing the cycle life potential of the main and primarily important components of the ATJE on the assessment basis of their damage exhaustion degree was determined.

2

Fuzzy-based Description of Computational Complexity of Central Nervous Systems

Prokopowicz Piotr, Mikołajewski Dariusz, Tyburek Krzysztof, Kotlarz Piotr

Journal of Telecommunications and Information Technology

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2020

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nr 3

57--66

EN

Computational intelligence algorithms are currently capable of dealing with simple cognitive processes, but still remain inefficient compared with the human brain’s ability to learn from few exemplars or to analyze problems that have not been deﬁned in an explicit manner. Generalization and decision-making processes typically require an uncertainty model that is applied to the decision options while relying on the probability approach. Thus, models of such cognitive functions usually interact with reinforcement-based learning to simplify complex problems. Decision-makers are needed to choose from the decision options that are available, in order to ensure that the decision-makers’ choices are rational. They maximize the subjective overall utility expected, given by the outcomes in diﬀerent states and weighted with subjective beliefs about the occurrence of those states. Beliefs are captured by probabilities and new information is incorporated using the Bayes’ law. Fuzzy-based models described in this paper propose a diﬀerent – they may serve as a point of departure for a family of novel methods enabling more effective and neurobiologically reliable brain simulation that is based on fuzzy logic techniques and that turns out to be useful in both basic and applied sciences. The approach presented provides a valuable insight into understanding the aforementioned processes, doing that in a descriptive, fuzzy-based manner, without presenting a complex analysis.

3

Modelling of wastewater treatment plant operation under variable conditions

Kończak Beata, Zawadzki Piotr, Pieczonka Michał

Instal

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2020

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nr 4

42--49

EN

Modelling of the wastewater treatment plant in Żory, Poland was carried out using the BioWin 2.1 simulation program based on the real data regarding acquired in 2016-2017. It was made the static and dynamic calibration of the developed model of the treatment plant. The calibration and verification procedure was performed. In order to determine the optimal working conditions for the WWTP Żory, a series of simulation tests were carried out (44 simulations of the WWTP Żory model work). The simulations were carried out for: variable wastewater temperature, uniform and uneven distribution of wastewater to individual biological sequences, at variable sludge age and rate of the internal recirculation, and variable oxygen concentration in the nitrification and denitrification tanks. It was also investigated the influence of the external carbon source dosing, and the management method of wastewaters recycled from dewatering system, on the effectiveness of nitrogen removal in simulation conditions. The simulation studies resulted in determination of the optimal parameters for the WWTP Żory work, considering the variable inflow parameters, in order to intensify removal of the nitrogen compounds by biological means, and to achieve the target concentration of the total nitrogen at the outlet, i.e. 10 mgN/L.

PL

Modelowanie oczyszczalni ścieków w Żorach prowadzono z wykorzystaniem programu symulacyjnego BioWin 2.1 w oparciu o dane rzeczywiste pozyskane w latach 2016-2017. Dokonano kalibracji statycznej i dynamicznej opracowanego modelu oczyszczalni. Przeprowadzono procedurę kalibracyjną i weryfikacyjną. W celu określenia optymalnych warunków pracy dla OS Żory wykonano szereg badań symulacyjnych (44 symulacje pracy modelowej OS Żory). Symulacje prowadzono dla: zmiennej temperatury ścieków, równomiernego i nierównomiernego rozdziału ścieków do poszczególnych ciągów biologicznych, przy zmiennym wieku osadu czynnego, stopniu recyrkulacji wewnętrznej i stężeniu tlenu w komorze tlenowej i denitryfikacji. Zbadano także wpływ dozowania zewnętrznego źródła węgla i sposobu gospodarowania wodami nadosadowymi na efektywność usuwania azotu w warunkach symulacyjnych. Efektem przeprowadzonych badań symulacyjnych było wyznaczenie optymalnych parametrów pracy OS Żory z uwzględnieniem zmiennych parametrów dopływu, w celu intensyfikacji usuwania związków azotu na drodze biologicznej i osiągnięciu docelowego stężenia azotu ogólnego na odpływie, tj. rzędu 10 mgN/L.

4

Computational Simulation Analysis for Dynamics of Multibody System Coupled with Flexible Deformation of Valve Train

Sun L., Shu G.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 9b

166-171

EN

Rigid and flexible multibody dynamics simulation analysis for the valve train of gasoline engine is conducted on the basis of the different constraints conditions, which among components have been varied in accordance with the kinematic and dynamic characteristics of the system to gradually approximate actual working conditions. Based on Lagrangian equation，absolute Cartesian coordinate and the floating frame of reference formulation for multibody dynamics, the computational dynamic simulation method used in professional simulation approach within computer program of UGNX is employed hereby to compute the displacement curve, velocity curve and acceleration curve of intake valve and exhaust valve, which elaborate the feature of valve motion, dynamic properties of the parts and whole system. Simulation results illustrate that computational dynamics of multibody system is an effective approach to analyze the dynamical characteristic of complex mechanical system in the flexible multibody model on the way of being high fidelity of the real constraints and load conditions of complex mechanical system with the consideration of all nonlinear factors arising from contact and impact constraint, flexible deformation of components and valve spring with designed parameters.

PL

Analiza i symulacja dynamiki szeregu zaworów w silniku benzynowym zawiera zwykle szereg ograniczeń. Przedstawiono nową metodę analizy bazującą na równaniach Lagrange’a i płynnej zmianie odniesień. Metodę zaimplementowano w oprogramowaniu UGNX.

5

Computational Simulations of Stress Distribution in Surrounding of Graphite Particles

Kopas P., Handrik M., Jakubovičová L., Sága M.

Machine Dynamics Research

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2010

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Vol. 34, No. 3

115-123

EN

The goal of the paper has been to present a computational simulation of the stress distribution in the surrounding of graphite particles. There were designed four algorithms for creation fields with random shape of graphite particles. Based on quantitative and qualitative evaluating of these algorithms it can be seen that the only appropriate field generation procedure with graphite particles is algorithm call "diffusion of carbon". Main objective of statistical processing of analysis result is determination of the 99.8% quantile stress concentration function for one or more graphite particles.

6

Investigation of the flow conditions in a high-performance heat exchanger

Łopata S., Ocłoń P.

Archives of Thermodynamics

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2010

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Vol. 31, no. 3

37-53

EN

CFD (Computational Fluid Dynamics) computations are carried out in order to investigate the flow distribution and its influence on the heat transfer processes in the high-performance heat exchanger. The subject of this investigation is the classical model of the high-performance heat exchanger with elliptical tubes and rectangular fins. It is possible to find the flow domains where the heat transfer conditions are impaired due to the fully developed turbulent flow. Therefore, the considerable thermal loads occur that may cause the breakdown of the heat exchanger. The emphasis of this investigation is put on the zones and the locations where the tubes are not properly fed with liquid, that result in occurrence of cavitation.

7

Modelling of quenching process of medium-carbon steel

Kulawik A., Bokota A.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 1

83-88

EN

The paper refers to numerical modelling of the hardening process of steel C45. In the algorithm the heat transfer equation, equilibrium equations and macroscopic model of phase transformations, basis of CCT diagrams, are used. Coupling between basic phenomena of hardening process is considered, in particular the influence of latent heat on the fields of temperature, and also thermal, structural and plastic strains and transformation - induced plasticity in the model is taken into account as well. The method of calculating the phase transformation during heating applied by the authors uses data from the continuous heating diagram (CHT). The homogenization line of austenite determines the end of heating. The influence of austenisation temperature on the kinetics of transformations is taken into account. To calculate the increase of martensite content Koistinen-Marburger formula is used. Field of stresses and strains are obtained from solutions of finite element method equations of equilibrium in increment form.

8

Symulacja numeryczna ruchu cząstek w płynach magnetycznych

Barski M.

Czasopismo Techniczne. Mechanika

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2009

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R. 106, z. 3-M

3-21

PL

Tematem niniejszego artykułu jest komputerowa symulacja zachowania się cząstek magnetycznych w cieczy magnetoreologicznej poddanej działaniu zewnętrznego pola magnetycznego. Opisano tutaj możliwie najprostszy model teoretyczny płynu magnetycznego. Wykorzystując ten model, badano wpływ zróżnicowanej wielkości cząstek na ich ostateczny rozkład w płynie nośnym. W sytuacji, gdy wszystkie cząstki mają identyczny promień, struktura wewnętrzna składa się z izolowanych, regularnych łańcuchów, ułożonych równolegle do kierunku wektora natężenia zewnętrznego pola magnetycznego. Kształt struktury wewnętrznej, uzyskany przy założeniu różnej wielkości cząstek, jest zasadniczo różny.

EN

This article is devoted to a numerical simulation of magneto-rheological fluids behavior under external magnetic field. The most simplest theoretical model of magnetic fluid is described. Using this model, the influence of magnetic particle size on internal structure is investigated. in the case, when all particles have the same size and shape, the obtained internal structure consists of single isolated strings of particles. The direction of these strings is parallel to the direction of external magnetic field. As the size of magnetic particles is variable, the shape of internal structure is completely different and the strings form clusters.