Browsing by Subject "numerical simulation"

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Access status: Open Access ,
Analiza numeryczna zachowania się stalowego gazociągu usytuowanego na różnych wysokościach osuwiska
(Wydawnictwa AGH, 2023) Kowalska-Kubsik, Iwona
Praca dotyczy analizy numerycznej zachowania stalowego gazociągu na osuwisku. Osuwiska są powszechnym zjawiskiem geologicznym, mogącym uszkodzić gazociągi. Wykorzystano zaawansowane metody obliczeniowe, m.in. model gruntowy Druckera–Pragera i dynamiczny oraz statyczny model obliczeniowy. Analiza numeryczna pozwoliła ocenić wpływ miejsca położenia gazociągu na naprężenia, odkształcenia i ryzyko uszkodzeń. Wyniki badań dostarczyły wartościowych informacji inżynierskich do projektowania, konstrukcji i utrzymania gazociągu. Optymalizacja projektu, materiałów i systemów podparcia zmniejszy ryzyko uszkodzeń. Wnioski z analizy mogą pomóc instytucjom regulacyjnym i operatorom gazociągów w zarządzaniu ryzykiem związanym z osuwiskami, poprawiając bezpieczeństwo i niezawodność infrastruktury gazowej.
Access status: Open Access ,
Computer-aided prototyping of interdigital transducers for the structural health monitoring of planar structures
(2013) Mańka, Michał; Ambroziński, Łukasz; Uhl, Tadeusz
In recent years an intensive research activity into the application of guided waves (GWs) for structural health monitoring (SHM) can be observed. For instance, Lamb waves (LWs) have shown a great potential in monitoring of thin, planar structures. However, due to the dispersive and multimodal nature of the LWs, their snapshots can consist of many pulses even for an intact structure, which makes damage detection very complex. Moreover, small PZT transducers, most commonly used in SHM systems, act normally as omni-directional wave sources, therefore, dense or sparse transducers networks are required for damage localization. Some of the above-mentioned drawbacks of single PZT emitters and sensors can be overcome using interdigital transducers (IDT) designed to excite and sense a single, selected mode. The mode-tuning is performed by changing the span of finger electrodes to match the wavelength of the excited mode for the selected frequency. An IDT is a directional source, therefore, it generates a wave steered to the direction perpendicular to the electrodes. The width of the excited main lobe can be determined by the length of the electrodes. Since many parameters of the IDTs infl uence the LWs propagation, techniques for the simulation of the wave excitation and propagation are needed. In the paper, numerical tools for the computer aided design and virtual prototyping of the IDTs are presented. The simulation technique is based on the frequency-dependent transfer function of the structure, and due to its computational efficiency it can be used for fast testing of IDTs’ performance and for preliminary transducer design for further finite element simulations, and prototyping.
Access status: Open Access ,
Design of a solidification rate measurement experiment for cast steel in molds made of different sands using computer simulation
(AGH University Press, 2025) Mordyl, Natalia; Jakubski, Jarosław; Żak, Paweł Leszek
This article presents the design process of the casting technology for a step-shaped casting made of steel using simulation tools. A series of proposals for gating and feeding systems were simulated in the MAGMASoftÂ® software. Results of numerical simulations allowed the Authors to select the casting technology which allows defect-free casting to be obtained. A numer ical analysis of the cooling rate of a step-shaped casting made of GX70CrMnSiNiMo2 tool steel with a 5% Ti addition was carried out for the selected manufacturing technology. Due to the nature of the material used and the extended presence of martensite during cooling, in-mold hardening of the casting may occur. The simulations showed that the type of molding material affects the cooling rate, which is confirmed by the analysis of cooling curves and the morphology of shrinkage po rosity. The analysis of solidification rates provides a valuable starting point and basis for subsequent research stages, taking into account the actual properties of the molding sands and the phase transformations occurring in the selected steel type. The casting technology design, which ensures the production of sound casting, was developed as part of this study. A series of simulations using different molding materials confirms the significant impact that the choice of mold material has on the casting solidification and cooling process.
Access status: Open Access ,
Development and analysis of kinematics of working unit of self-propelled drilling machine
(Wydawnictwa AGH, 2018) Karliński, Jacek; Działak, Paulina; Bałchanowski, Krzysztof; Wudarczyk, Sławomir
Self-propelled drilling rigs are widely used in the underground mining. Their main task is to drill holes in the rocks where explosive charges are to be placed. An important feature of this type of machine is its ability to drill holes according to the blasting parameters defined in the documentation. Precision regarding the hole distribution and angular deviation is crucial for fragmentation of the rocks. This paper presents the results of a kinematic analysis of the working unit of a drilling rig designed for KGHM Polska Miedź S.A. The authors determined the design and construction aspects influencing the accuracy of the drilling boom positioning. The working field of the described system was equal to 45 m?.
Access status: Open Access ,
Development and verification of the scale growth model during high temperature oxidation for S235 steel
(Wydawnictwa AGH, 2020) Przyłucka, Aleksandra; Cebo-Rudnicka, Agnieszka; Rywotycki, Marcin; Augustyn-Nadzieja, Joanna; Malinowski, Zbigniew
Every year rapid industrialization and the following urbanization fuel the global demand for steel. The use of steel products contributes to the sustainable development of society. The scale growth mechanism accompanies the high-temperature plastic working of metals and alloys. The article focuses on the thickness of the scale formed as a result of annealing steel samples in a furnace. Samples made of S235 (A283C) steel were heated at two temperatures, 1100°C and 1200°C, for 8 minutes. The amount of scale formed was determined on the basis of photos taken with a light microscope. The transformed equations of steel oxidation kinetics were used in the computational part. The scale thickness obtained numerically corresponded to the scale formed in real conditions. The aim of the research was to adjust the scale growth model on steel so that it gives correct results in relation to the actual thickness of the formed oxidized layer.
Access status: Restricted ,
Eksperymentalne i numeryczne określanie charakterystyk wentylatora promieniowego w obudowie spiralnej
(Data obrony: 2015-07-20) Grzywacz, Katarzyna
Wydział Energetyki i Paliw
Access status: Open Access ,
Evaluation of deformation inhomogeneity in multi-layered steel-titanium and steel-magnesium systems
(Wydawnictwa AGH, 2025) Pabich, Bartłomiej; Żurowski, Bartłomiej; Kwiecień, Marcin; Majta, Janusz
In the presented study, plastometric tests using channel die compression were employed to define the boundary conditions for numerical simulations of the deformation processes of heterogeneous multi-layer systems composed of microalloyed steel, titanium, or magnesium. Various configurations, conditions, and deformation schemes were applied, which were then replicated in numerical simulations. Rheological models were used in the studies which, through computer simulations, enabled the modeling of interactions between the incoherent components of the microstructure. The primary outcome of the conducted experimental studies and numerical simulations is the ability to assess the heterogeneity of the studied multi-layer systems in terms of their mechanical states and influence on microstructural changes. This heterogeneity additionally arises from the diverse microstructural and rheological characteristics of the investigated materials (BCC vs. HCP), which, in turn, affect the strengthening mechanisms, primarily strain hardening. The results obtained from channel die compression tests were then used in simulations of multi-stage wire drawing, supporting both the design phase and the analysis of the resulting microstructural effects in the studied heterogeneous systems. It was observed that one of the key criteria for designing heterostructured wires from the examined materials is the proper selection of the volume fraction of the components, as well as the deformation history during multi-stage wire drawing, considering interpass heat treatment.
Access status: Open Access ,
Gas-condensate banking and well deliverability - a comparative study using analytical- and numerical models
(2016) Ursin, Jann Rune
Reservoir condensate blockage in the reservoir and in particular in the close vicinity of the wellbore may result in significant loss of well deliverability for medium to tight gas reservoirs. The dynamics of fluid flow in these types of reservoirs are investigated by way of analytical description and by numerical simulation of radial two phase flow behavior. The analytical model is based on a single phase semi steady-state solution, being revised for two phase flow of gas and condensate oil. As the liquid is dropping out of the gas, a saturation distribution of immovable oil is seen to develop radially in the reservoir with time. Condensed oil not being part of this saturation distribution is produced to the surface. The numerical model is a cylindrical, single well, fine gridded, simulation model run on the Eclipse E300 compositional simulator. The base case study comprises a rich gas condensate fluid (GOR ~ 1000 Sm3/Sm3), an initial gas-in-place volume of 750 MSm3, and reservoir permeability of 10 mD. A gas flow rate of 0.5 MSm3/day is leading to a production period of about 4 years. A comparative study is performed by varying parameters such as pressure development, development of bank of immovable oil both radially and as function of time, condensate blockage effects, and gas and condensate oil production and onset of reduced well deliverability. Sensitivity analysis are performed by studying variation in the productivity index, non-Darcy and mechanical skin, and sensitivities related to permeability. It has been confirmed in this study that condensate blockage has a direct and negative impact on well deliverability, where both the plateau period and the bottom hole pressure are reduced. We also show that the analytical model compares well with the numerical models and that many features describing gas-condensate banking and well deliverability are adequately described in the model. The analytical model also offers insight into the process of reservoir liquid storage in gas condensate reservoirs.
Access status: Open Access ,
Influence of ladle shroud and change in its position on liquid steel flow hydrodynamic structure in six-strand tundish
(Wydawnictwa AGH, 2018) Bartosiewicz, Michał; Cwudziński, Adam
This paper presents the numerical simulation results of the liquid steel flow in a six-strand tundish used for casting billets. The influence of using a ladle shroud, changing its immersion depth in liquid steel on the transition zone, and shaping the liquid steel volume flow were tested. Three positions of the ladle shroud immersion depth in liquid steel were checked. The computer calculation results have shown that the use and position change of the ladle shroud locally influences the shape of the liquid steel hydrodynamic structure in the tundish. The numerical simulations were carried out using the Ansys-Fluent computer program.
Access status: Open Access ,
Numerical simulation heat transfer in the slab tundish
(2007) Cwudziński, Adam; Jowsa, Jan
The article presents the results of computer simulations of heat transfer in a slab tundish. The tundish was equipped with a dam with two holes. The authors employed the CFD (Computational Fluid Dynamics) numerical modelling technique to demonstrate the effect of change of steel temperature flow to tundish on the distribution of temperature field. The computer simulations were performed for non-steady conditions. As a result of computations, time characteristics of temperature change and fields of temperature for slab tundish were obtained. Results of simulation were examined through industrial experiment.
Access status: Open Access ,
Numerical simulation of drilling fluid flow in annular the space of the borehole
(2015) Kowalska-Kubsik, Iwona
This paper presents the numerical results of a numerical analys is of drilling fluid flow through annular space in the borehole. The analysis used the Herschel–Bulkley rheological fluid model. The obtained results of the analysis for three cases with variable geometry. Variable geometry is associated with a larger diameter drill in the joints of drill pipes, and consequently, with reduced flow cross-section. A comparison of pressure values at the end of the analyzed examples showed that in the example of a simple drill pipe with out joints, pressure values were 30% higher than in the case, which takes into account changes in the geometry of the joints.
Access status: Open Access ,
Optimization of casting technology of the pressure die cast AZ91D Mg-based alloy
(2010) Piwowarski, Grzegorz; Krajewski, Witold; Lelito, Janusz
Pressure die casting has become the next area of experimentation on virtual models in computer memory. The article presents an attempt to optimize the manufacturing process of an item made of magnesium AZ91D alloy, which was cast using the pressure technology on a machine with a hot pressing chamber. Special attention was paid to the flow velocity in individual parts of the gating system and in the mould cavity, as well as to the air evacuation from the mould cavity. The aim was to achieve a flawless casting, especially in terms of porosity.
Access status: Open Access ,
Optimization of simulation model parameters for solidification of metals with use of agent-based evolutionary algorithm
(Wydawnictwa AGH, 2008) Kluska-Nawarecka, Stanisława; Smolarek-Grzyb, Agnieszka; Byrski, Aleksander; Wilk-Kołodziejczyk, Dorota
The finite elements method (FEM) is currently widely used for simulation of thermal processes. However, one of still unresolved problems remains proper selection of mathematical model parameters for these processes. As far as modelling of cooling casts in forms is concerned, particular difficulties appear while estimating values of numerous coefficients such as: heat transport coefficient between metal and form, specific heat, metal and form heat conduction coefficient, metal and form density. Coefficients mentioned above depend not only on materials properties but also on temperature. In the paper the idea of optimalization of simulation method parameters based on adaptive adjustment of curve representing simulation result and result obtained in physical experiment is presented along with the idea of evolutionary and agent-based evolutionary optimization system designed to conduct such optimizations. Preliminary results obtained with use of ABAQUS system available in ACK CYFRONET and software developed at AGH-UST conclude the paper.
Access status: Open Access ,
Optimization of well placement and control to maximize CO₂ trapping during geologic sequestration
(2016) Stopa, Jerzy; Janiga, Damian; Wojnarowski, Paweł; Czarnota, Robert
The $CO_{2}$ injection into geological formations such as saline aquifers can be effective method of sequestration enabling efficient immobilization of gas by surface and capillary forces. The main objective of presented method of optimization was to determine optimal well position and injection rates that maximize residual trapping. This would mitigate the risk of the $CO_{2}$ leakage outside of storage zone. A genetic algorithm and particle swarm optimization have been developed and coupled with reservoir simulator to optimally examine various placement and injection control strategies for vertical as well as horizontal well. Optimization was carried out in 3D heterogeneous real field model with water-$CO_{2}$ -formation rock relationship. Numerical examples confirm that developed algorithm can find a promising optimal solution effectively within a partial number of simulation runs.
Access status: Open Access ,
Simulation analysis for the efficiency enhancement of Sb2S3 solar cell using SCAPS-1D
(Wydawnictwa AGH, 2023) Oglah, Mubarak Hamad; Mahmood, Watban Ibrahim; Basheer Adday, Nawras
The simulation analysis was performed to enhance the efficiency of Sb2S3 solar cells using the SCAPS-1D software. The $Sb_{2}S_{3}$ compound was used as the absorber layer in the solar cell. The simulation was conducted to verify the efficiency and accuracy of the results obtained from the program. The results were found to be in agreement with the practical results. The original cell’s efficiency was 11.47% with a fill factor of 61.18%, and after the simulation, the efficiency was found to be 11.43% with a fill factor of 61.2%. To enhance the efficiency of the solar cell, a reflective background layer (BSL) was added. Different BSL layers were examined, including SnS, Si, CIGS, CZTSSe, and $CU_{S}bS_{3}$, and the best reflective layer was found to be $CU_{S}bS_{3}$. The solar cell structure was designed as follows: $glass/Mo/CUSbS_{3}/Sb_{2}S_{3}/CdS/i:ZnO/AL:ZnO$. After adding the reflective layer, the efficiency of the solar cell was found to be 20.59% with a fill factor of 87.53%. The results suggest that adding reflective layers to solar cells can enhance their performance and increase their efficiency.
Access status: Open Access ,
Simulations of the behavior of a pipeline made from three different types of materials on a landslide
(Wydawnictwa AGH, 2024) Kowalska-Kubsik, Iwona
The study presents numerical analyses of the behavior of pipelines made from various materials (steel, polypropylene, composite) under landslide conditions. Landslides are phenomena most commonly occurring in foothill and mountainous areas, and pipelines located on slopes can sustain damage during the landslide process. To determine the nature and extent of potential damage, numerical simulations were conducted based on advanced computational methods. The analysis employed the Drucker-Prager constitutive soil model. Numerical analyses make it possible to determine the deformation and stress states in pipelines without the need for costly experimental studies. By comparing simulation results for different materials, it is possible to assess the suitability of various pipes for placement on slopes.
Access status: Open Access ,
Symulacja numeryczna obróbki cieplnej odlewu ze staliwa i jej weryfikacja doświadczalna
(Wydawnictwa AGH, 2023) Żołynia, Szymon; Sobula, Sebastian
The problem of the heat treatment technology of cast steel with use of modern simulation tools is important to the today’s engineer. The main purpose of thesis was experimental verification of the numerical simulation results of L500-II carbon cast steel heat treatment. In accordance to the assumption, a computer simulation of the heat treatment process was carried out using the Visual-Weld (Sysweld) software. Experimental tests, during which the cooling curves were recorded, were carried out simultaneously. After conducted quenching in water, the hardness distribution on the cross-section of the sample was examined, as well as the microstructure in selected areas, using a light microscope and ImageJ software. It was shown, that the results of the numerical simulation are different from those obtained in the experiment.