Browsing by Subject "simulation"

Now showing 1 - 20 of 42

Access status: Open Access ,
A simulation and experimental investigation of the thermal characteristics of refractory bricks produced using fireclay and agroforestry wastes
(AGH University Press, 2022) Obidiegwu, Eugenia Obiageli; Esezobor, David Ehigie; Mgbemere, Henry Ekene; Chiosa Odili, Cletus
Manufacturing and processing industries usually consume large quantities of materials and energy in the course of their operations. The energy supplied for high-temperature processes are used partially for the actual technical process and between 30 to 40% of the energy escapes through the walls of the reactor into the atmosphere, leading to a high degree of thermal inefficiency and fuel consumption. This paper studies the thermal behaviour of insulating refractory bricks produced from a blend of fireclay and agroforestry wastes. The fireclays used were obtained from Ukpor deposit in Anambra State (Latitude 5.95°N, Longitude 6.92°E), Osiele deposit in Abeokuta, Ogun State (Latitude 7.18°N, Longitude 3.45°E) and Kankara Katsina State (Latitude 11.93°N, Longitude 7.41°E), all of which are in Nigeria. Samples were prepared with various weight percentages (60-100 wt.%) clays and (0-40 wt.%) of agroforestry waste, with grain sizes between 212 and 600 µm. Raw materials and the developed refractory bricks were characterised using appropriate standard techniques. The chemical, mineralogical constituents and phases present in the microstructure were examined. Physical and thermo-mechanical properties were investigated. The insulating refractory bricks developed have porosity of 78.83% , cold crushing strength (CCS) 3.144 kN/m$^{2}$ and thermal conductivity 0.04-0.046 W/(m$\cdot$K) that compare favourably with imported bricks 75-85%, 2.756 kN/m$^{2}$ and 0.049 W/(m$\cdot$K) in both physical, mechanical and thermal properties respectively. The reason is that the agroforestry waste used (coconut shell), served to create the pores that improve insulation after burning. Also the ash that remains serves as reinforcement to improve the mechanical properties. The thermal behaviour of the bricks was studied using Finite Element Method and shows a strong correlation with the experimental findings. This indicates that the produced insulating bricks have the thermal properties required for insulation of furnaces.
Access status: Open Access ,
A thermal model of the building for the design of temperature control algorithms
(Wydawnictwa AGH, 2014) Skruch, Paweł
W pracy przedstawiono efektywne i skuteczne podejście do modelowania dynamiki zmian temperatury w pomieszczeniach budynków mieszkalnych i użyteczności publicznej. Konstrukcja modelu matematycznego opiera się na jednoczesnym wykorzystaniu podstawowych zasad termodynamiki oraz praktycznych metod inżynieryjnych dotyczących obliczania parametrów cieplnych elementów konstrukcyjnych budynku. Model uwzględnia moc cieplną traconą przez pomieszczenie (ciepło tracone przez przewodnictwo oraz wentylację) oraz moc cieplną dostarczoną do pomieszczenia (ciepło z instalacji grzewczej, promieniowanie słoneczne, wewnętrzne zyski ciepła). Parametry modelu są obliczane z geometrii budynku i na podstawie właściwości termicznych materiałów budowlanych. Model może być wykorzystany do projektowania i analizy algorytmów sterowania procesem ogrzewania pomieszczeń. Praca zawiera również przykład modelu matematycznego, który został zbudowany przy wykorzystaniu rozważanego podejścia dla jednokondygnacyjnego budynku mieszkalnego. W symulacjach komputerowych zbadano zmiany temperatury w poszczególnych pomieszczeniach przy typowej instalacji grzewczej, w której ogrzewanie pomieszczeń jest sterowane przez niezależnie działające baterie termostatyczne.
Access status: Restricted ,
Analiza możliwości rewitalizacji wybranego złoża ropy naftowej
(Data obrony: 2011-10-11) Ruciński, Piotr Paweł
Wydział Wiertnictwa, Nafty i Gazu
Access status: Open Access ,
Considering semi-crystallinity in molecular simulations of mechanical polymer properties - using nanoindentation of polyethylene as an example
(Wydawnictwa AGH, 2021) Fritz, Susanne
Molecular dynamic (MD) simulations have been used to investigate the response of semi-crystalline polymers in nanoindentation tests, using polyethylene (PE) as an example. To that purpose, semi-crystalline simulation boxes of linear PE with various chain lengths up to C2000 were created by homogeneous nucleation during the non-isothermal cooling of melts. The final crystallinity depended on the chain length and the cooling rate used and could be estimated using various parameters like density, fraction of bonds in trans conformation, and energy terms. The simulation boxes were transferred into surface models and subjected to nanoindentation tests using non equilibrium MD. This allowed the deformation behaviour of the material to be analysed directly. Strong dependencies on the crystallinity of the PE were found, which underlines the importance of considering crystallinity when investigating the mechanical properties of semi-crystalline polymers by means of simulations.
Access status: Restricted ,
Dynamiczny model otoczenia pojazdu
(Data obrony: 2018-10-16) Grzyb, Damian
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Open Access ,
Effect of cavitation phenomenon on the quality of high-pressure aluminium alloy castings
(AGH University Press, 2023) Brzeziński, Marcin; Wiśniowski, Jakub
This article presents an analysis of the effect of cavitation on the erosion of pressure moulds intended for the HPDC casting mould manufacturing process. Changes in the surface area of the eroded areas were investigated via photographs of castings at the begin-ning of the mould life as well as at 30%. The individual process variables were described and their influence verified via the cavitation potential module of the Flow3D simulation programme. The results are presented graphically with a description of the relationships and observations. The summary provides an explanation of the results and the dependencies that occurred.
Access status: Restricted ,
Generacja energii w elektrowni fotowoltaicznej typu „wschód-zachód”
(Data obrony: 2017-01-23) Śladowski, Arkadiusz
Wydział Geologii, Geofizyki i Ochrony Środowiska
W pracy inżynierskiej poddano analizie pracę dwóch typów elektrowni fotowoltaicznych różniących się orientacją modułów PV. W pierwszym przypadku wszystkie moduły zorientowane były w kierunku południowym, a w drugim część modułów została ustawiona w kierunku wschodnim, a część zachodnim. Symulację pracy elektrowni przeprowadzono z wykorzystaniem oprogramowania PV SOL. Na podstawie danych otrzymanych w wyniku symulacji porównano zarówno roczne uzyski energii, jak również dzienne i roczne profile generacji energii z elektrowni „wschód-zachód” oraz „południe”. Oprócz tego analizowano korelację pomiędzy profilem produkcji energii i profilem jej konsumpcji w zależności od orientacji paneli. Dane uzyskane z symulacji porównano z danymi rzeczywistymi, zarejestrowanymi dla pracującej instalacji PV.
Access status: Restricted ,
Hardware-in-the-loop simulation concept in the development of radar-based perception algorithms for active safety, advanced driver assistance and autonomous driving systems
(Data obrony: 2018-10-23) Burza, Rafał
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Open Access ,
Laser melted steel free surface formation
(2007) Siwek, Aleksander
Two-dimensional mathematical model of recasting steel by laser was presented in this paper. Surface velocity and liquid temperature for several powers of laser beams and sulfur contents were obtained as results of numerical modeling of liquid flow and heat exchange processes. The shape of free surface in a melted zone was computed with the use of iterative method proposed in this paper.
Access status: Open Access ,
Looking for big money in the grey zone. Simulation of high yield investment programs strategies
(Wydawnictwa AGH, 2015) Gniadzik, Katarzyna; Kowalik, Grzegorz; Jarczyk, Oskar; Nielek, Radosław
High Yield Investment Programs (HYIPs) are online versions of a Ponzi scheme, a fraud that offers extremely high interest rates to attract investors – and pays them up to the moment when HYIP owner decides to run away with the money accumulated in the account. This article presents a simulation focused on the connections between investments in appealing websites, advertising, and runaway strategies to explore and describe one of the grey zone areas. The model is based to a large extent on real-life data acquired from HYIP monitors. In this paper, we have proven that advertising and layout have a great impact on an HYIP’s balance. Moreover, most HYIPs are capable of gaining similar balance, however, there are also conservative strategies that significantly reduce profits.
Access status: Open Access ,
Methodics of assessing environmental noise emission while performing hydraulic fracturing operations in shale formations
(2016) Łukańko, Łukasz; Macuda, Jan
Hydraulic fracturing operations performed at the stage of gas prospection in shale formations are aimed at opening out gas residing in rock micropores. Large quantities of fracturing fluid, with physicochemical composition adjusted to their properties, are injected to the selected interval of a horizontal well. Finally, sand (proppant) is injected along with the fracturing fluid to support the newly formed fracture. The results of a computer simulation of noise emission generated by high pressure pumps during hydraulic fracturing operations, and the results of noise measurements during such work in the north of Poland are presented in the paper. The analysis of the obtained results revealed that the noise standards for day hours in the residential area localized ca. 320 m from the well pad was not exceeded for the hydraulic fracturing operations. The noise level in the night hours was considerably higher, therefore a respective sound berm should be construed.
Access status: Restricted ,
Modelowanie i symulacja ruchu w rozległej sieci drogowej
(Data obrony: 2019-01-16) Karaś, Piotr
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Restricted ,
Modelowanie węzła sieci IEEE 802.11 w pakiecie MatLab
(Data obrony: 2014-01-30) Konior, Piotr
Wydział Informatyki, Elektroniki i Telekomunikacji
Access status: Restricted ,
Nano-network performance analysis in human vascular system
(Data obrony: 2021-01-26) Wierzbicki, Mikołaj
Wydział Informatyki, Elektroniki i Telekomunikacji
Access status: Restricted ,
Narzędzia symulacyjne do testowania algorytmów sterowania autonomiczną kosiarką
(Data obrony: 2017-01-20) Kozieł, Łukasz
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Open Access ,
Numerical simulation and co-simulation in analysis of manipulators’ dynamics
(2013) Baran, Dariusz; Lisowski, Wojciech
Application of general purpose computing environments to analysis of manipulators’ dynamics gives ability to select elastically the model structure and analysis algorithms, as well as full access to the intermediate results, however, it often requires introduction of various simplifications of the model under consideration. The alternative approach consists in application of the specialized software packages that allow the use of more sophisticated models, but at the cost of restricted access to the intermediate results as well as the limited range of possible modifications of models and solution algorithms. The authors focused on application of the co-simulation technique in analysis of manipulators’ dynamics. Co-simulation consists in application of specialized software packages to formulation of the dynamic model. Next, the model is simulated with use of a general purpose computing environment and co-operating specialized software package. The authors used Matlab/Simulink computing environment and MD ADAMS software package. The paper presents comparison of results, problems of application, as well as remarks on educational applicability of manipulator dynamics analysis with use of the simulation and the co-simulation techniques. Two examples of a manipulator dynamics modelling were considered. One example with a considerably simplified mass spatial distribution, and another one with a mass distribution corresponding to a real commercial manipulator. The achieved analysis results confirmed that application of the co-simulation technique eases the use of complex models in analysis of manipulator dynamics with use of the general purpose computing environments.
Access status: Restricted ,
Numeryczna analiza rozkładu cząstek $SiC$ w stopie AZ91 na przykładzie wybranego odlewu
(Data obrony: 2014-02-04) Stojecki, Piotr Karol
Wydział Odlewnictwa
Access status: Restricted ,
Obraz religii chrześcijańskiej w reklamie w świetle teorii symulacji Jeana Baudrillarda
(Data obrony: 2013-07-04) Krzosek, Magdalena
Wydział Humanistyczny
Access status: Open Access ,
Ocena niepewności wyników statycznej symulacji sieci gazowych
(2009) Łaciak, Mariusz
Modelling and simulating gas-pipe network is a significant part of difficulties during planning as well as operating process. Most of computational methods referred to gas-pipe network, exhibit some errors in calculations. This paper presents reason-effect analysis of errors occurring in statistical simulation. Paper describes most of the parameters related to exploration gas-pipe network that can lead to an error in calculation using statistical simulation.
Access status: Restricted ,
Off-line programming of industrial robot
(Data obrony: 2014-09-30) Wu, Pengpeng
Wydział Inżynierii Mechanicznej i Robotyki