Browsing by Subject "numerical modelling"

Now showing 1 - 20 of 27

Access status: Open Access ,
2D Electrical Resistivity Tomography interpretation ambiguity - example of field studies supported with analogue and numerical modelling
(Wydawnictwa AGH, 2013) Bania, Grzegorz; Ćwiklik, Michał
Single Electrical Resistivity Tomography (ERT) survey was carried out in the Manor and Park Complex in Nowa Huta (Krakow Branice, Poland). It was applied at a small distance and parallel to the longer wall of a monumental building containing an empty 3 m deep basement. Analogue modelling was performed in order to recreate the field study at the proper scale. The laboratory set-up consisted of a water tank where electrodes were mounted to the particular plate, which rested on water surface. The basement model was made out of a non-conducting material. The default and robust inversions were tested and these variants were also considered with the use of numerical modelling. Laboratory experiments have confirmed that zones visible in the interpreted field section are caused by the influence of the building cellar located next to the survey line. Zones of this kind are additionally disturbed by the local geological structure. The experiment has pointed out, among others, that as the distance between the survey line and the underground body increases, the inversion results are still burdened by an object influence. Thus, similar situations can be verified with the use of analogue modelling presented in this paper or 3D numerical one.
Access status: Open Access ,
A Big Data processing strategy for hybrid interpretation of flood embankment multisensor data
(Wydawnictwa AGH, 2016) Chuchro, Monika; Franczyk, Anna; Dwornik, Maciej; Leśniak, Andrzej
The assessment of flood embankments is a key component of a country’s comprehensive flood protection. Proper and early information on the possible instability of a flood embankment can make it possible to take preventative action. The assessment method proposed by the ISMOP project is based on a strategy of processing huge data sets (Big Data). The detection of flood embankment anomalies can take two analysis paths. The first involves the computation of numerical models and comparing them with real data measured on a flood embankment. This is the path of model-driven analysis. The second solution is data-driven, meaning time series are analysed in order to detect deviations from average values. Flood embankments are assessed based on the results of model-driven and data-driven analyses and information from preprocessing. An alarm is triggered if a critical value is exceeded in one or both paths of analysis. Tests on synthetic data demonstrate the high efficiency of the chosen methods for assessing the state of flood embankments.
Access status: Open Access ,
A comprehensive designation of tailings storage dams – a case study of the sangan iron mine project in Iran
(Wydawnictwa AGH, 2023) Maleki, Shaho; Khalilidermani, Mitra
Tailings storage dams are considered to be one of the most essential facilities in mining projects. In metal mines, after blasting the rocks, the blasted ore is transferred to specific industrial plants for processing operations. During such operations, a large amount of pollutant tailings are inevitably generated. Those tailings must be safely stored in previously constructed storage dams. In this research, a storage dam has been designed to store the tailings of the Iranian Sangan Iron Mine project. The geometry and capacity of the dam were designed to minimize the construction works and to maintain the stability of the facility. To assess the stability of the proposed storage dam, a numerical analysis was performed for both static and dynamic loading conditions. The results showed that the embankment is stable under these two different loading conditions. Hence, the proposed design can be successfully adopted for the construction of a tailings storage dam in the project. In addition, the methodology presented in this research can be used by geotechnic engineers to design safe tailings storage dams in mining projects.
Access status: Open Access ,
A contribution to the design of powered roof support for operations in a rockburst-hazardous environment
(Wydawnictwa AGH, 2020) Świątek, Janina; Stoiński, Kazimierz; Styrylski, Konrad
The paper presents an example of a numerical analysis using ANSYS to optimise the design of powered roof support designed to operate in rock mass tremor hazard conditions. The areas of excessive stress in the structure of powered roof support were identified, taking into account the increase in rock mass loading resulting from tremors. An increase in the load impacting on the support as a result of rock mass tremors is the cause of excessive stresses in the section structure. The paper aims to identify them and to find ways to apply the design using numerical analysis. The analysis was conducted for roof support type ZRP-15/35-POz produced in Repair and Production Plant (ZRP-Bieruń) of Polish Mining Group S.A. (PGG S.A.) The introduction of reinforcements in places of increased stress in the support section structure should increase its operational safety in the excavation.
Access status: Restricted ,
Analiza stateczności wałów przeciwpowodziowych przy Moście Kotlarskim w Krakowie, przy możliwym występowaniu zróżnicowanych, powodziowych stanów wód
(Data obrony: 2017-09-27) Zając, Łukasz
Wydział Geologii, Geofizyki i Ochrony Środowiska
W pracy przedstawiono analizę stateczności wałów przeciwpowodziowych, zlokalizowanych przy Moście Kotlarskim w Krakowie, przeprowadzonej w oparciu o modelowanie numeryczne. Uwzględniono dynamicznie zmieniające się położenie zwierciadła wody w Wiśle pomiędzy stanami charakterystycznymi dla powodzi dziesięciolecia a pięćsetlecia. Opisano metodologię przeprowadzonej analizy wraz z omówieniem wyników.
Access status: Open Access ,
Closed die forging of turbine disc to fix blades from Inconel$^®$718
(2011) Chyła, Piotr; Łukaszek-Sołek, Aneta; Bednarek, Sylwia; Chyła, Paweł
In the paper numerical analysis of closed-die forging process of turbine disc to fix blades was presented. Forging technologies which take into account conventional and isothermal boundary conditions were analysed. Forging processes were lead as one stage or as two stages - with initial upsetting. In the analysis additional influence of lubrication conditions on the process parameters was taken into account.
Access status: Open Access ,
Eksploatacja złoża w sąsiedztwie zrobów i stref upodatnionych w świetle doświadczeń praktycznych oraz modelowania numerycznego
(2007) Butra, Jan; Pytel, Witold M.
Bump and roof fall hazard potential is assessed based on the practical observations and numerical (FEM) modeling of mining operations conducted near the already mined-out and/or yielding zones.
Access status: Open Access ,
Electrical and thermal analysis for the copper removal process in an electric furnace
(Wydawnictwa AGH, 2023) Zybała, Radosław; Golak, Sławomir; Sak,Tomasz; Madej, Piotr
The article presents an electrical model of a resistance furnace with two electrodes encompassing the generation of Joule heat. The characteristic feature of this model was the consideration of contact resistance between the electrodes and the slag. A series of analyses were conducted based on this model. Firstly, the impact of contact resistance on current flow and Joule heat generation in the furnace was assessed, demonstrating its significant importance. A separate group of analyses focused on the spatial configuration of the furnace and its interaction with the aforementioned phenomena. The impact of symmetric and asymmetric electrodes immersion was analysed. In addition to the impact on current flow, the study also demonstrated the influence on the natural convection mechanism described by the proposed measures of the spatial non-uniformity of heat generation. The research showed that symmetric electrode immersion allows for the generation of more heat in the system at a constant voltage. Asymmetric electrodes immersion causes an increase in the non-uniformity of heat generation, which translates into a higher intensity of natural convection.
Access status: Open Access ,
Forging process in three tool folding die
(2008) Chyła, Paweł; Bednarek, Sylwia; Łukaszek-Sołek, Aneta; Sińczak, Jan; Skubisz, Piotr
The aim of the paper was presentation control lubrication influence on forging process and apply possibilities. Numerical modeling of the forging process in three tool folding die has been presented. Five different variants of lubrication method have been analysed in order to define lubrication influence on the filling process of the die impression. The results indicate full usefulness of presented lubrication method in planning forging technologies.
Access status: Open Access ,
Influence of initial water saturation in earthen levees on results of numerical modelling of infiltration processes
(Wydawnictwa AGH, 2017) Dwornik, Maciej; Franczyk, Anna; Leśniak, Andrzej; Krawiec, Krzysztof
Levees in Poland are mostly earthen constructions. The stability of earthen levees depends largely on factors such as the construction material, meteorological conditions and natural elements. The influence of initial water saturation of pore space on levee stability is analysed in this paper. Analysis was performed using numerical modelling and water pore pressure results were compared against data obtained from sensors located in a levee. The numerical modelling shows the moderate influence of initial water level on distribution of water pore pressure during high water level.
Access status: Open Access ,
Komputerowa symulacja stanu naprężenia w sąsiedztwie wyrobiska górniczego z uwzględnieniem przepływu gazu
(Wydawnictwa AGH, 2010) Walaszczyk, Jan; Florkowska, Lucyna
One of the natural dangers in coal mining in Poland is methane migration between rock layers. The following paper discusses that issue. The main aim of the paper was to obtain stress distribution around mining excavation area, considering the influence of methane pressure and the process of methane migration through gaps into layers previously without it. In particular, the paper presents a simulation of processes occurring in rock mass during coal exploitation when the migration of methane from lower layers is possible. The issue was solved by numerical modelling, using the Finite Element Method. MES-Abaqus code was used for calculations.
Access status: Open Access ,
Modeling of near-net forging of thin-walled parts of strain rate sensitive alloy
(2005) Bednarek, Sylwia; Sińczak, Jan; Skubisz, Piotr
Numerical modelling of a single-operation forging process of a radial bladed impeller forging as one piece is presented. The analysis have been performed using high-melting-alloy model material. A several alternative technologies differing in temperature and forming speed. Evaluation of the correctness of a forging process were based on distribution of effective strain, effective strain rate, mean stress as well as fllling of the cavities of a die-impression in thin-walled ribs type areas.
Access status: Open Access ,
Modelling of the system for cleaning up free oil products with the application of the MARS simulator
(2013) Knez, Janusz; Knez, Dariusz
Nowadays one of the most important problems in environmental protection is the pollution of groundwater by derivative products of oil. A common case of the infiltration of the oil derivative products to the ground water system is mainly connected with accidental oil spills in various types of environmental conditions. In this case we encounter numerous types of problems connected especially with the pollution in: 1) aeration zones, 2) saturation zones. The first step is a conceptual model for the proper recognition of the type and scale of the problem. After making a conceptual model it is possible to take a preliminary decision to recognize what sort of pollution is the source of the environmental problem. A study example describes modeling of free products of oil (LNAPL) floating on the groundwater table using MARS (Multiple Areal Remediation Simulator). The multiphase model was made on the basis of theoretical model concepts. In the modeling the recovery and migration of LNAPL are simulated, and the recoverable and residual spill volumes of derivate products of oil are estimated. Modeling indicates the best location of the remediation system and the pumping wells. Additionally, modelling can be applied to manage the remediation system for improving the efficiency and for decreasing the catchment area of piezometers and wells
Access status: Open Access ,
Modelowanie numeryczne górotworu wokół wyrobiska korytarzowego narażonego na wpływy ciśnień eksploatacyjnych
(2007) Prusek, Stanisław; Masny, Wojciech; Walentek, Andrzej
This paper presents results from numerical modeling of the rock mass around an excavation which is exposed to different mining-induced pressure. The numerical modeling was based on the in-situ measurement in the longwall tailgates. The measurements were carried out in the Polish hard coal mines.
Access status: Open Access ,
Modelowanie numeryczne wpływu górniczych deformacji podłoża na grupę budynków w zwartej zabudowie miejskiej
(Wydawnictwa AGH, 2009) Florkowska, Lucyna
The prediction of the influence of subsoil deformations on the condition of a building system is of great importance as, among other things, it helps prevent mining damages. Results of the numerical modelling influence of the underground mining on the buildings in the high-density housing were introduced at work. Recognizing the possibility of calculating stress and strain state on the base of standard geodetic measurements and numerical simulation was the purpose of this the work. Although the applied numerical model was simplest model, results of experiment showed themselves very much interesting.
Access status: Open Access ,
Modelowanie wpływu zaburzeń tektonicznych na drgania stropu w górotworze uwarstwionym
(Wydawnictwa AGH, 2008) Walaszczyk, Jan; Wiewiórka, Dariusz
Phenomenon of dynamic relieving present in paper and methodic of numerical modeling this problem. Numerical model of group of room present in interaction area of big fault. Diagrams in result of account received displacement, velocities and acceleration in chosen points of models. It implement analysis about diagrams of changes of tensions in pillars and enclosing of them. Numeric errors in digital filtration of result use eliminating.
Access status: Open Access ,
Numerical analysis of the influence of lubrication conditions on the filling pattern in a complex process of extruding particular high-melting materials
(2012) Krawiec, Agnieszka; Chyła, Paweł; Chyła, Piotr; Bednarek, Sylwia; Łukaszek-Sołek, Aneta
In this paper, the process of extrusion was analyzed numerically for a axisymmetric forging model where there is a complex material flow diagram (Fig. 1a). The analysis was performed assuming a different stoke slenderness ratio so you can control how to fill the die impression (direct extrusion, in direct and side - Fig. 1b)-d), using lubricants with different values of friction factor.
Access status: Open Access ,
Numerical model for dendrite growth - an application of the Rank Controlled Differential Quadrature method
(2012) Żak, Paweł; Suchy, Józef Szczepan
Rank Controlled Differential Quadrature (RCDQ) is an innovative method for numerical approximation of problems described by Partial Differential Equations (PDEs). In this paper the authors apply the RCDQ for the numerical simulation of a simplified model for dendrite growth during Al-Ti alloy crystallization. The authors put most concern on building an accurate numerical model for this phenomenon. In the simplified model the symmetry and flux on boundary condition appears. Additionally, dendrite tip growth into adjacent liquid change the computation domain size, what indicates a need for node coordinate recalculation during each new time step. The authors analyze the results of numerical modelling of alloying element concentration and dendrite growth rate. The modelling results shows that the RCDQ method can be used for modelling problems with moving grid and that the method approximation proposed by the authors is proper.
Access status: Open Access ,
Numerical modelling of continuous laser welding of S355J2 steel using a volumetric heat source
(Wydawnictwa AGH, 2023) Siwek, Aleksander; Kąc, Sławomir; Pikuła, Janusz
Numerical modelling of laser welding requires that numerous strongly coupled physical phenomena be taken into account. A laser is a source of welding heat characterized by the small size of the heating volume and the shape of the fusion zone has a marked impact on the quality of the weld. In this work, a conical heat source was used with geometrical parameters to give the appropriate profile of the fusion line. The use of the weld shape factor and the dependence of the power density on the linear welding energy increases the accuracy of matching the calculated shape of the fusion line. The heat source was tested for the continuous welding case of a sheet made of steel type S355J2. The CFD software ANSYS Fluent was used to calculate the welding model. The temperature field, calculated using the finite volume method, was used to calculate the phase composition and fusion zone profile tracking. The nodes of the model reaching the maximum solidus temperature of S355J2 steel, form the profile of the fusion zone. The laser welding model allows for tracking of the kinetics of phase transformations in the cooling stage. Continuous cooling transformation phase diagram data is loaded for the welded steel grade. The calculation results of the welding model were compared with the weld micrographs.
Access status: Restricted ,
Ocena warunków krążenia wód podziemnych w górnym fragmencie zlewni rzeki Sołokiji
(Data obrony: 2017-09-26) Smuszkiewicz, Michał
Wydział Geologii, Geofizyki i Ochrony Środowiska
The study aimed to assess the groundwater circulation conditions in the upper Solokija river basin. This evaluation was based on results of the numerical modelling conducted in Processing Modflow programme. The modelling process was preceded by the collection of bibliographic data, field study and computer data processing using the ArcGIS software package. The analyzed area is characterized by favorable hydrogeological conditions, and the little scaled anthropopressure does not pose a threat to water resources.