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  1. 8 Journal of Achievements in Materials and Manufacturing Engineering
  2. 5 Przegląd Elektrotechniczny
  3. 3 Archives of Materials Science and Engineering
  4. 2 Computer Assisted Mechanics and Engineering Sciences
  5. 2 Computer Assisted Methods in Engineering and Science
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  1. 44 Nowak A. J.
  2. 14 Dobrzański L. A.
  3. 14 Smołka J.
  4. 7 Ostrowski Z.
  5. 5 Pusz A.
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1
Content available Boundary-only formulations of the boundary element method
100%
Nowak A. J.
Journal of Theoretical and Applied Mechanics
|
1998
|
tom nr 2
479-491
EN
In the paper possible treatments of the domain integrals appearing in BEM are discussed. Major approaches are compared and critically evaluated with emphasis put on the dual and reciprocity reciprocity techniques. New trends in these methods involving new interpolation functions and decomposition are presented.
PL
W artykule omówiono sposoby całek po całym obszarze występujących w metodzie elementów brzegowych. Podstawowe algorytmy obliczeniowe zostały krytycznie porównane ze szczególnym uwzględnieniem metod wykorzystujących zasady wzajemności: podwójną oraz wielokrotną. Zaprezentowano również trendy w tych technikach obliczeniowych, a w szczególności nowe funkcje interpolujące oraz metodę dekompozycji obszaru.
2
Duchowosc czlowieka a srodowisko
100%
Nowak A. J.
Środowisko i Rozwój
|
2002
|
nr 05-06(1-2)
3
Content available remote Efektywne chłodzenie cewek suchego transformatora elektrycznego za pomocą kanałów chłodzących o optymalnej konfiguracji
63%
Smołka J. , Nowak A. J.
Przegląd Elektrotechniczny
|
2011
|
tom R. 87, nr 5
218-223
PL
W pracy przedstawiono optymalizację wzajemnej konfiguracji rozdzielanych cewek GN oraz DN, a tym samym kanałów chłodzących uzwojenia dla suchego transformatora. Funkcją celu była minimalizacja temperatury najgorętszego miejsca uzwojenia, którą wyznaczano za pomocą zweryfikowanego eksperymentalnie modelu wykorzystującego numeryczną mechanikę płynów (ang. CFD). Wyniki badań pokazały, że nierównomierne rozmieszczenie kanałów oraz drutów może znacząco poprawić warunki odprowadzenia ciepła z urządzenia, co przekłada się na zmniejszenie jego strat mocy.
EN
In this work, an optimisation of mutual configuration of separated both HV and LV coils, and in the same time cooling ducts in electrical transformer is presented. An objective functions is minimization of the hot-spot temperature that is determined using experimentally validated CFD model. The obtained results showed that a non-uniform positioning of ducts and coil wires lead to a more effective heat dissipation from the device. In consequence, the coil power losses are also substantially reduced.
4
Content available remote Wear abrasive resistance of intracorporeal prosthesis of oesophagus
63%
Nowak A. J. , Dobrzański L. A.
Journal of Achievements in Materials and Manufacturing Engineering
|
2015
|
tom Vol. 69, nr 1
26--32
EN
Purpose: The main aim of the work is investigation of abrasive wear resistance of evaluated oesophageal prosthesis internal layer, considering its long-term exploitation possibility and extreme option of food consumed by patient after implementation. Design/methodology/approach: In the work, methodology of wear abrasive investigations of oesophageal prosthesis, made of long-fibre composite material based on medical silicon, internal surface is presented. The measurements have been done on equipment designed and made in Division of Materials Processing Technology, Management and Computer Techniques in Materials Science of Institute of Engineering Materials and Biomaterials. Findings: The volume of obtained samples mass loss have been determined from approximate calculations of wear trace to simple geometrical figure mapping this loss, ant then the volume of this figure haves been calculated. The CAD software has been used to verify approximation method, which allows to precisely determine mass loss. Research limitations/implications: Developed constructional model of modern, internal prosthesis of the human oesophagus will be used to design the manufacturing technology and to manufacture given prosthesis. Originality/value: Worked out construction is the part of the research project realized by authors, that will result in cognitive, constructional and technological effects, but first of all, it will enable the real help very sick people.
5
Content available Mechanical analysis of multilayer composite materials with duroplastic matrix after exposure to low temperatures
63%
Krzak A. , Nowak A. J.
Archives of Materials Science and Engineering
|
2023
|
tom Vol. 122, nr 2
49--57
EN
Purpose: Cryogenic engineering is gaining more and more interest in various industry sectors, which leads to an intensive search for effective solutions. The article presents the findings of mechanical testing conducted on glass-epoxy laminates at room temperature and after long- term contact with liquid nitrogen. Design/methodology/approach: To compare the impact properties and flexural strength, the samples were tested under cryogenic and room conditions, and then the fracture locations were identified using the Leica DVM6 microscope. The study brings value to the emerging field of cryogenic engineering by providing valuable information on the mechanical properties of glass-epoxy composites under cryogenic conditions. Findings: It has been found out that immersing the glass-epoxy composites into the Dewar had minimal influence on impact and flexural strength properties. The most noticeable changes were observed in the case of the EP_4_2 composite. The material consists of a solution of brominated epoxy resin in an organic solvent. It is used to produce laminates in electrical engineering and printed circuits in electronics, where it should exhibit excellent impact properties. Research limitations/implications: One of the prospective research directions is a thorough analysis of the mechanical properties of the developed composite materials during cryogenic cycles. Originality/value: The study aims to determine the effect of different compositions of glass fabric-reinforced resin with a weight of 205 g/m2 on the mechanical properties of the developed composite materials at both room temperature and after long-term exposure to liquid nitrogen. Those investigations serve as surveillance for developing of new material solutions directed towards cryogenic applications and are essential for subsequent stages of research.
6
Content available remote Modyfikacja konfiguracji cewek suchego transformatora elektrycznego w celu obniżenia temperatury najgorętszego miejsca
63%
Smołka J. , Nowak A. J.
Przegląd Elektrotechniczny
|
2011
|
tom R. 87, nr 7
60-63
PL
W artykule przedstawiono optymalizację wzajemnego położenia cewek GN i DN oraz kanałów chłodzących te elementy dla suchego transformatora. W przeprowadzonych obliczeniach minimalizowano temperaturę najgorętszego miejsca uzwojenia, którą wyznaczano za pomocą zweryfikowanego eksperymentalnie modelu numerycznego CFD. Wyniki badań pokazały, że najkorzystniejsze rozwiązanie, znacząco obniżające temperatury cewek, różni się od dotychczas stosowanych konfiguracji w tego typu jednostkach.
EN
In this work, an optimisation of mutual configuration of both HV and LV coils, and also air ducts cooling these parts in dry-type electrical transformer is presented. In the proposed algorithm, the hot-spot temperature is minimized using experimentally validated CFD model. The obtained results show that the optimized solution substantially reduces the maximum winding temperature comparing to a typical configuration of the actual devices.
7
Optimization of cooling duct shape in a naturally ventilated electrical transformer
63%
Smołka J. , Nowak A. J.
Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne
|
2010
|
tom Z. 15
142-149
EN
A shape optimization of cooling ducts in try-type transformers using Computational Fluid Dynamics (CFD) and Genetic Algorithm (GA) is presented in this paper. The GA algorithm was used to optimize the diameters of the ducts and both internal and external part of the HV and LV coils. The constraints in the optimization process were the minimum distance between HV and LV windings and total dimensions of the coils. Since the investigated transformer was a special unit, the objective function was to minimize the average/maximum temperature of the windings, and thus the coil power losses. Its value was determined a CFD model taking all three heat transfer mechanisms into consideration. Both coil anisotropic properties and coil power losses varied in each generated coil configuration. The results showed that the non-uniform positioning of the wires and air ducts can significantly improve the cooling conditions of the analyzed unit. In consequence, the coil losses were substantially reduced.
8
Content available Badania struktury geometrycznej powierzchni wewnątrzustrojowej protezy przełyku
63%
Nowak A. J. , Dobrzański L. A.
Przetwórstwo Tworzyw
|
2015
|
tom T. 21, Nr 4 (166)
337--342
PL
W pracy przedstawiono metodologie badań chropowatości powierzchni wewnętrznej i zewnętrznej wewnątrzustrojowej protezy przełyku wykonanej z długowłóknistego materiału kompozytowego o osnowie silikonu medycznego. W ramach rozwinięcia powierzchni zewnętrznej protezy zastosowano teksturowanie, które miało ułatwić osadzanie się ludzkich komórek i przerost tkanką własną zaiplantowanego pacjenta. Badania wykonano metodą liniowego, mechanicznego pomiaru stykowego oraz w ramach weryfikacji metodą profilometrii optycznej na mikroskopie konfokalnym. Celem pracy było zbadanie chropowatości powierzchni opracowanej protezy przełyku przed i po teksturowaniu aby ocenić jej wpływ na przyszłościowe zastosowanie protezy.
EN
The research methodology of the roughness of internal and external surface of internal oesophageal prosthesis made of long-fibre composite material with medical silicone matrix is described in the article. External surface texturing of the prosthesis was applied to facilitate human cells deposition and hypertrophy of the tissue in the body of the patient, Linear, mechanical contact-measurement method and, for verification, optical profile measurement in confocal microscope were used. The aim of the work was roughness investigation of the surface of developed oesophageal prosthesis before and after texturing, to estimate its influence on future application of prosthesis.
9
Content available remote Geometrical structure investigation of the surface of internal oesophagus prosthesis
63%
Nowak A. J. , Dobrzański L. A.
Archives of Materials Science and Engineering
|
2017
|
tom Vol. 83, nr 2
79--85
EN
Purpose: The aim of the work was roughness investigation of the surface of developed oesophageal prosthesis before and after texturing, to estimate its influence on future application of prosthesis. Design/methodology/approach: Linear, mechanical contact-measurement method and, for verification, optical profile measurement in confocal microscope were used in the work. Findings: The roughness investigation of the surface of developed oesophageal prosthesis before and after texturing was necessary to estimate its influence on future application of prosthesis. Research limitations/implications: The results of investigations of prosthesis of the human oesophagus internal and external surface roughness will be used to design the manufacturing technology and to manufacture given prosthesis. Originality/value: Investigation of geometrical structure of internal and external surface of internal oesophageal prosthesis is the part of the research project realized by authors, that will result in cognitive, constructional and technological effects, but first of all, it will enable the real help very sick people.
10
Content available remote Wykorzystanie ciepła odpadowego do przygotowania wody kąpielowej w kopalni węgla
51%
Nadziakiewicz J. , Nowak A. J. , Rudnicki Z.
Przegląd Górniczy
|
1998
|
tom T. 54, nr 5
27-34
PL
W pracy rozważono możliwości techniczne wykorzystania energii odpadowej zawartej w wodzie dołowej do przygotowania wody kąpielowej w kopalni węgla kamiennego. Zaproponowane roz-wiązanie oparte jest na sprężarkowej pompie ciepła, w której rozważono alternatywnie zarówno freonowy, jak i ekologiczny czynnik ziębniczy. Analiza uwzględnia również obliczenie kosztów przedsięwzięcia, na podstawie o oferty producentów, oraz wy-znaczenie czasu zwrotu inwestycji. W pracy wskazano także na aspekty ekologiczne zaproponowanego rozwiązania.
EN
Technical possibilities of waste energy contained in the underground water utilization for bath water preparation at a hard coal mine are considered. Proposed solution is based on the compressor heat pump in which use of freon as well as an ecological cooling agent is cosidered. The analysis includs also calculation of the project cost based on produsers tenders as well as payout time. Ecological aspects of the proposed solution are also poited out.
11
Content available remote The effect of micropores on output properties of laminate materials with assumed medical implantation
51%
Dobrzański L. A. , Pusz A. , Nowak A. J.
Journal of Achievements in Materials and Manufacturing Engineering
|
2009
|
tom Vol. 37, nr 2
408-415
EN
Purpose: Examination of elaborated composite material in terms of specific application in medicine – as internal prostheses of oesophagus. Development of the manufacturing technology of aramid-silicon laminated material and definition of the micro-cavities amount formed during production of the laminates. Design/methodology/approach: Aramid-silicon laminated material was made by a method of manual formation of laminates that is impregnation of reinforcement with matrix to hardening silicone process using hardening methods connected with heat. Created material was observed on Axiovert 450M light-microscope of Option Company at 100 x magnification. Findings: The results show that the preliminary manufacturing technology of aramid-silicon laminated materials allows creating a material with specific and special properties. Aramid-silicone laminate could be used in medicine for example as oesophagus prosthesis. Research limitations/implications: Carried out investigations show the problem with cautioning and ageing which are very important in having proper percentage of intensifier in developed material. Originality/value: Taking the material specific properties into account it seems that the aramid-silicon laminated material would be useful in medicine. Aramid silicone laminate could be attractive alternatively for composite material used for medical purposes and the others.
12
Content available remote The concept of preparation of oesophageal prosthesis based on long-fibre composite materiał
51%
Dobrzański L. A. , Nowak A. J. , Błażejewski W. , Rybczyński R.
Journal of Achievements in Materials and Manufacturing Engineering
|
2011
|
tom Vol. 46, nr 1
18--24
EN
Purpose: In the work, there was investigated the possibility of an application of long-fibrous composite material as a based material for prototype of oesophageal prosthesis (tubular element) with the use of so called arms, using coiling, plaiting and winding techniques. Design/methodology/approach: Coiling, plaiting and winding techniques were used. As a reinforcement, aramid fibres bound with different types of so called silicone rubbers. Selection of winding parameters has been made in order to fabrication of prosthesis with appropriate mechanical parameters. Findings: Technological tests have given promising results. In the summary, comments and technological remarks are described. For prototype of prosthesis manufacturing, components, which in the form of composite materials are characterized by biocompatibility, have been used, that is medical silicone and aramid fibres. Research limitations/implications: The pilot investigation of fabricated prototypes of internal oesophageal prosthesis show that it is necessary to change the fabrication technology onto dry winding followed by closing obtained reinforcement in a mould and saturation with silicone. The idea is to get better silicone content and connected with it better elasticity and tightness of the prosthesis. Originality/value: Accepted method of winding is the most effective due to fabrication of prototypes of internal oesophageal prosthesis in laboratory. In industry, probably the better method will be plaiting, e.g.: as in the case of high-pressure hose of applied hydraulics.
13
Content available remote CFD model of coupled thermal processes within coke oven battery as an example of complex industrial application
51%
Nowak A. J. , Smołka J. , Fic A. , Kosyrczyk L.
Computer Assisted Mechanics and Engineering Sciences
|
2010
|
tom Vol. 17, no. 2-3-4
161-172
EN
This paper describes results of the mathematical modelling of steady-state and transient physical phenomena taking place in the heating channels of a coke oven battery. A formulated system of standard Computational Fluid Dynamics (CFD) equations coupled with User Defined Functions is solved numerically using commercial software Ansys Fluent. Finally, the developed 3-D model is used to examine the influence of selected operating parameters on the resulting temperature, velocity and concentration fields within considered object. The obtained results are briefly discussed considering their physical correctness related to industrial measurements.
14
Content available remote Zastosowanie metody elementów skończonych do modelowania wewnątrzustrojowej protezy przełyku
51%
Nowak A. J. , Dobrzański L. A. , Rybczyński R. , Mech R.
Przetwórstwo Tworzyw
|
2013
|
tom [R.] 19, nr 4 (154)
384--389
PL
W pracy przedstawiono symulację komputerową wewnątrzustrojowej protezy przełyku, wykonanej z długowłóknistego materiału kompozytowego, z wykorzystaniem Metody Elementów Skończonych (MES). Modelowanie naprężeń wewnętrznych protezy wykonano w środowisku ANSYS Workbench. Dodatkowo w pracy przedstawiono zalety stosowania tego typu oprogramowania. Zastosowana MES pozwoliła na modelowanie naprężeń i odkształceń powstających w materiale kompozytowym, zarówno w warunkach odwzorowujących rzeczywiste badania doświadczalne, jak i w warunkach przybliżonych do panujących w organizmie człowieka po zaimplantowaniu protezy. Opracowana symulacja upraszcza oraz zmniejsza koszty optymalizacji własności wewnątrzustrojowej protezy przełyku przez symulację tych własności bez konieczności wykonywania dodatkowych badań laboratoryjnych.
EN
The general topic of this paper is the computer simulation with the use of Finite Element Method (FEM) for determining the internal stresses in the internal oesophageal prosthesis based on long-fibre composite material. Modelling of stresses in the internal oesophageal prosthesis was performed with the help of FEM in ANSYS environment. Application of FEM was discussed and essential advantages resulting from application of it are pointed. Applied FEM enables modelling of stresses and deformations arises in composite material in the conditions representing real experimental investigations as well as condition similar of those prevailing in human body after prosthesis implementation. Developed simulation simplifies and reduces cost of optimization of the internal oesophageal prosthesis properties by simulation of this properties without necessity of additional laboratory investigations.
15
Content available remote Numerical modelling and analysis of cooling system of electrical transformer dipped into polymerised resin
51%
Smołka J. , Nowak A. J. , Wrobel L. C.
TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
|
2003
|
tom Vol. 7, No 3
439-448
EN
This paper discusses a numerical model of the heat dissipation processes in an electrical transformer dipped into polymerised resin. The transformer is cooled by both natural convection (via the ambient air) and forced convection (via the water cooling system attached to one of the transformer casing walls). Two cases have been compared, i.e. the cooler connected to the bottom or the top wall of the transformer container, respectively. In order to improve the modelling of the natural convection problem, an independent geometrical model of the surrounding air was created and considered separately. The continuity of temperature and heat flux along the interface between the transformer and air was enforced by an iterative procedure. This procedure allowed one to calculate and then prescribe local heat fluxes to the external walls of the transformer. The numerical results obtained in this project have yielded information on the efficiency of the analysed cooling system.
16
Odtwarzanie kształtu obszaru w trójwymiarowym modelu ciągłego odlewania stopu aluminium
51%
Nowak I. , Smołka J. , Nowak A. J.
Rudy i Metale Nieżelazne
|
2010
|
tom R. 55, nr 2
63-71
PL
W artykule przedstawiona została metoda określania położenia i kształtu frontu zmiany fazy na podstawie pomiarów temperatury w wybranych punktach części stałej wlewka. Przedstawiony problem jest przykładem geometrycznego zadania odwrotnego, w którego opisie matematycznym brakuje informacji na temat kształtu obszaru. W pracy geometryczne zadanie odwrotne sformułowano dla trójwymiarowego modelu ciągłego odlewania stopu aluminium. Algorytm odtwarzania kształtu frontu zmiany fazy oparto na analizie wrażliwości, a do jego modelowania wykorzystano powierzchnię Beziera. W zaproponowanej metodzie określenie wrażliwości odbywa się na drodze analitycznej poprzez rozwiązanie odpowiednio zdefiniowanego zadania bezpośredniego uzyskiwanego (poprzez różniczkowanie) z problemu przepływu ciepła dla ciągłego odlewania. Artykuł jest w pewnym sensie kontynuacją opublikowanej wcześniej pracy [5], dotyczącej odtwarzania warunków brzegowych w identycznym modelu i przy wykorzystaniu analogicznych metod.
EN
In this paper, a method to determine both shape and location of the phase change front is presented. The retrieved quantities are obtained based on a temperature measured at selected internal points. The considered problem is an example of the geometry inverse problem. Its mathematical description is incomplete because the information about the shape of the body is either unknown or uncertain. The geometry inverse problem was formulated as a 3-D model of aluminium alloy continuous casting. The retrieving algorithm employed the sensitivity analysis, while the geometry of the estimated front is modelled by Bezier surface. The sensitivity is determined using the analytical method based on the solution of an appropriate direct problem obtained from relevant thermal problem of the continuous casting. The paper is a continuation of the work [5] in which the retrieving of boundary conditions for an identical model and using similar methods was discussed.
17
Content available remote Aramid-silicon laminated materials with special properties-new perspective of its usage
51%
Dobrzański L. A. , Pusz A. , Nowak A. J.
Journal of Achievements in Materials and Manufacturing Engineering
|
2008
|
tom Vol. 28, nr 1
7-14
EN
Purpose: Development of the manufacturing technology of aramid-silicon laminated material. Design/methodology/approach: Aramid-silicon laminated material was made by method of manual formation of laminates, that is impregnation of reinforcement with matrix, to hardening silicone process using hardening methods connect with hot. Created material was being observed by using MEF4A light-microscope of Leica company at 25-500x magnification. Findings: The results show that the preliminary manufacturing technology of aramid-silicon laminated materials allows to create a material with specific and special properties. Aramid silicone laminate could be attractive alternative for composite material used in medical and others purposes. Research limitations/implications: Carried out investigations show the problem with cautioning and ageing which are very important in having proper percentage of intensifier in developed material. Originality/value: Taking into account the material specific properties one can suppose that the aramid-silicon laminated material would be useful in medicine. Aramid silicone laminate could be attractive alternative for composite material used in medical and others purposes.
18
Content available remote Numerical modelling of a multi-physical problem within an encapsulated three-phase transformer and its surroundings
51%
Smolka J. , Nowak A. J. , Ingham D. B. , Elliot L.
TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
|
2006
|
tom Vol. 10, No 1
63-81
EN
The paper presents a numerical thermal model of an encapsulated three-phase electrical transformer. The model is based on the multi-physical approach and involves heat transfer analysis coupled with the examination of specific power losses in the coils and the core using electromagnetic field analysis as well as determination of thermal stresses. The thermal boundary conditions (i. e. local heat fluxes) are determined by considering a numerical model of the surrounding air. Additionally, the device is cooled via radiation (from the external walls) and forced convection (a water cooling system). A few different configurations of the cooler and the heat pipes are also analyzed. Moreover, anisotropic material properties were applied for stranded coils and the core. A partial experimental validation of the model has shown that the temperature distribution within the transformer is more realistic and closer to the measurements when compared with the previous analysis limited to heat transfer problems only with uniform internal heat sources and isotropic material properties. The total heat transfer rate indicates that forced convection is the most important heat dissipation mechanism in this model. The significance of the water cooling system has also been established in calculations of crack presence in the model.
19
Content available Wastewater treatment in constructed wetlands
51%
Nowak A. J. , Królik D. , Kostecki J.
Civil and Environmental Engineering Reports
|
2013
|
tom No. 11
93--99
EN
Constructed wetlands are an alternative and economically reasonable way for the wastewater from dispersed development treatment. Existing systems showed that the effectiveness of this treatment is high. The whole treatment process depends on many factors such as time of operation, type of filling, temperature. Constructed wetlands with proper construction and operation are safe for the environment and users.
PL
Oczyszczalnie hydrofitowe są alternatywnym i ekonomicznie uzasadnionym, sposobem na oczyszczanie ścieków pochodzących z zabudowań charakterze rozproszonym. Literatura oraz badania istniejących systemów ze złożem gruntowo roślinnym pokazują, że skuteczność oczyszczania ścieków jest wysoka. Na skuteczność wpływa wiele czynników tj. czasu eksploatacji, rodzaju wypełnienia złoża, temperatury. Hydrofitowe oczyszczalnie ścieków przy odpowiedniej budowie i eksploatacji są bezpieczne dla środowiska oraz użytkowników.
20
Odtwarzanie warunków brzegowych w trójwymiarowym modelu ciągłego odlewania stopu aluminium
51%
Nowak I. , Smołka J. , Nowak A. J.
Rudy i Metale Nieżelazne
|
2009
|
tom R. 54, nr 6
345-355
PL
W artykule przedstawiono trójwymiarowe rozwiązanie numeryczne odwrotnego zadania brzegowego sformułowanego dla ciągłego odlewania aluminium. Głównym celem prezentowanego zadania była identyfikacja strumienia ciepła wzdłuż zewnętrznych ścian wlewka na podstawie pomiaru temperatury w kilku punktach wewnętrznych. Do modelowania procesu odlewania użyto oprogramowania komercyjnego wykorzystującego technikę entalpową, w której front zmiany fazy określany był na podstawie udziału fazy ciekłej. Rozwiązane w ten sposób zadanie bezpośrednie wykorzystywano zarówno w procedurze odwrotnej, jak i do numerycznego generowania pomiarów temperatury. W procedurze odwrotnej, do estymacji odtwarzanych warunków brzegowych, wykorzystano analizę wrażliwości. W praktyce dane pomiarowe zawsze są obarczone błędami, dlatego sprawdzono, w jakim stopniu zaburzenia te przenoszą się na dokładność odtworzenia strumieni ciepła. Badano także wpływ wielkości startowych na przebieg procesu iteracyjnego oraz na dokładność uzyskanych rezultatów. W obydwu testach, zaproponowany algorytm doprowadził do zadowalających wyników. Omówiona metoda rozwiązywania odwrotnego zadania brzegowego może zostać wykorzystana do identyfikacji warunków brzegowych, także w zastosowaniach przemysłowych.
EN
Presented paper proposes an algorithm being an extension into 3D solution procedure developed for 2D boundary inverse problem. It discusses a numerical solution of the inverse boundary problem for a continuous casting process of aluminum alloy. The first task was to formulate a mathematical model and solve the direct heat transfer problem for a continuous casting using Fluent. The model served as a basis for the boundary inverse problem and was also employed to generate simulated temperature measurements for the application of the proposed inverse analysis algorithms. In the inverse heat transfer problem, the heat flux distribution along external walls of ingot is unknown. This means that the mathematical description is incomplete and needs to be supplemented, typically, by measurements. In the method presented design variables are modified in an iterative procedure on the basis of sensitivity analysis and comparison of the calculated in model temperatures and measured values. The iterative loops are repeated until the vector of estimated variables minimizes the objective function within a specified accuracy. The calculation of the sensitivity coefficients boils down to solving a set of direct problems similar to the thermal one. Each of these problems arise through differentiation of main thermal equation and corresponding boundary conditions with respect to the particular design variable determining the phase change front location. The boundary conditions along known boundaries are of the same type as in the original thermal problem, but homogeneous. The procedure developed for retrieving the cooling conditions in a continuous casting process turned out to be computationally very effective and independent on the starting value of the assumed boundary condition. A comparison of the measured and retrieved values showed a high accuracy of the computations. The satisfactory results were also obtained in calculations investigating the influence of the accuracy of measurements on the estimated heat fluxes. Some observations concerning the possibility of the calculation time reduction were also made.
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