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Gdańsk University of Technology

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Publications from the year 2019

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  • Nowa koncepcja poprawy elastyczności bloków parowych z zastosowaniem magazynów pary
    • Janusz Badur
    • Paweł Ziółkowski
    2019 INPE: Informacje o Normach i Przepisach Elektrycznych

    Celem niniejszej pracy jest krótki przegląd sposobów magazynowania energii i odniesienie się do sposobu, który byłby najdogodniejszy dla bloków parowych klasy 370-390 MWe. W niniejszej pracy zaproponowano innowacyjny magazyn pary, który jest integralną częścią obiegu parowego i dzięki temu szybko odpowiada na zmiany zapotrzebowania na energię elektryczną, a zatem może usprawniać świadczenia usługi regulacji pierwotnej przy jednoczesnym zachowaniu wysokiej sprawności konwersji energii. W odniesieniu do bloków energetyki zawodowej poprawia bezpieczeństwo pracy jednostek wytwórczych, gdyż zapobiega przeciążaniu termicznemu kotłów i turbin w przypadku wysokiego zejście z mocą lub w przypadku gwałtownych najazdów. Elektrownia parowa dostosowana do szybkich zmian mocy staje się bardziej konkurencyjna na rynku mocy poprzez poprawę charakterystyki dynamicznej.

  • NOWE MATERIAŁY ANODOWE DLA TLENKOWYCH OGNIW PALIWOWYCH (SOFCs) ZAPEWNIAJĄCE WYDAJNĄ PRACĘ W SYSTEMACH ZASILANYCH BIOGAZEM.
    • Patryk Błaszczak
    2019

    Tlenkowe ogniwa paliwowe (z ang. Solid Oxide Fuel Cells, SOFCs) zasilane paliwami innymi niż czysty wodór podlegają procesom szybszego niszczenia i utraty zdolności do generowania prądu. Głównymi przyczynami takiego zachowania jest osadzanie się węgla na powierzchni anody oraz zatruwanie materiałów ceramicznych śladowymi ilościami siarki, fosforu lub chloru w paliwach węglowodorowych. W niniejszej pracy dokonano przeglądu przez wybrane metody modyfikowania materiałów oraz struktury SOFC w celu poprawy wydajności ogniw zasilanych biogazem. Najnowsze badania dowodzą, że stosowanie warstw ochronnych opartych o tlenek ceru (CeO2) mogą może mieć korzystny wpływ na jakość działania ogniw paliwowych. Dodatkowo szereg materiałów wykazujących zdolność do tzw. eksolucji może zastąpić szeroko stosowany cermet Ni-YSZ. Materiały te są bardziej odporne na zatruwanie siarką, wspomagają usuwanie nagromadzeń węgla oraz stanowią doskonały materiał katalityczny po wprowadzeniu metali aktywnych takich jak Ni, Cu, Fe lub Co.

  • Nowe substancje psychoaktywne - nowe wyzwania analityczne
    • Laura Banaszkiewicz
    • Mateusz Kacper Woźniak
    • Marek Biziuk
    • Jacek Namieśnik
    2019 Full text Analityka: Nauka i Praktyka

    Nowe substancje psychoaktywne stanowią poważny problem ekonomiczno-społeczny i zdrowotny ze względu na swoje właściwości psychoaktywne oraz uzależniające. Niejednokrotnie zdarza się, że właściwości fizykochemiczne oraz wpływ na organizm człowieka związków z grupy NPS nie są zbadane zanim trafią do nielegalnego obrotu. Wśród substancji należących do NPS wyróżnia się takie grupy chemiczne jak: syntetyczne kannabinoidy, katynony, piperazyny, tryptaminy, fenyloetyloaminy, fentanyle inne. Każdego roku syntezowane są kolejne związki, co utrudnia ich oznaczanie na potrzeby analiz chemiczno-toksykologicznych. Różnorodność tych substancji implikuje konieczność opracowywania nowych procedur ich oznaczania. Obecnie, najczęściej wykorzystywaną techniką do oznaczania związków z grupy NPS w próbkach o złożonym składzie matrycy jest chromatografia cieczowa sprzężona z tandemową spektrometrią mas (LC-MS/MS), a na etapie przygotowania próbek coraz częściej stosuje się nowe metody ekstrakcji oparte na zasadach zielonej chemii analitycznej. W pracy dokonano przeglądu aktualnie używanych procedur oznaczania związków z grupy NPS (głównie syntetycznych katynonów i kannabinoidów, które są nadal najczęściej spotykanymi substancjami psychoaktywnymi) wraz z ich parametrami walidacyjnymi. Skupiono się na danych literaturowych z lat 2016-2018.

  • N-phosphonomethylglycine utilization by the psychrotolerant yeast Solicoccozyma terricola M 3.1.4.
    • Natalia Stosiek
    • Agata Terebieniec
    • Adam Ząbek
    • Młynarz Piotr
    • Hubert Cieśliński
    • Magdalena Klimek-Ochab
    2019 Full text BIOORGANIC CHEMISTRY

    SolicoccozymaterricolaM 3.1.4., the yeast strain isolated from soil sample from blueberry cultivation in MiedzyrzecPodlaski in Poland, is capable to split of phosphorus to nitrogen and nitrogen to carbon bonds inN-phosphono-methylglycine (PMG, glyphosate). The biodegradation process proceeds in the phosphate-independent manner. Itis the first example of a psychrotolerant yeast strain able to degrade PMGviaCeN bond cleavage accompanied byAMPA formation and not like in most microorganismsviaCeP bond disruption followed by the sarcosine pathway.Glyphosate oxidoreductase (GOX) type activity was detected in cell-free extracts prepared fromS.terricolaM 3.1.4.pregrown on 4 mM PMG as a sole phosphorus and nitrogen source in cultivation medium

  • Numerical Analysis of an Impact of Planned Location of Sewage Discharge on Natura 2000 Areas – The Dead Vistula Region Case Study
    • Piotr Zima
    2019 Full text Polish Maritime Research

    This article presents results of an analysis of impact of a designed discharge of contaminated water into the Dead Vistula (Wisła Martwa) in the region of the Isthmus (Przesmyk) with the aim of determination of a possible effect of the pollution onto protected areas of Natura 2000 (bird habitats and sites, especially the Bird Paradise – Ptasi Raj) nature reserve. The analysis was conducted on the basis of the two-dimensional modelling of unsteady transport of non-degradable dissolved matter. To this end, a numerical model of a section of the Dead Vistula was worked out. Four scenarios of hydro-dynamical conditions (2 – for average weather conditions and 2 – for stormy weather conditions) were selected. To solving the equation of pollution migration the finite volumes method (MOS) was applied. Two localizations of contaminated water discharge outlet were considered, namely: the first from the side of Siennicki Bridge before the Isthmus and the other in the section of the Brave Vistula (Wisła Śmiała) downstream the Isthmus. The obtained results made it possible to assess positively the first localization of the designed discharge outlet. In the other case there is a fear that at unfavourable hydro-meteorological conditions a water pollution may happen over Natura 2000 protected areas.

  • Numerical Analysis of Recharge Rates and Contaminant Travel Time in Layered Unsaturated Soils
    • Adam Szymkiewicz
    • Julien Savard
    • Beata Jaworska-Szulc
    2019 Full text Water

    This study focused on the estimation of groundwater recharge rates and travel time of conservative contaminants between ground surface and aquifer. Numerical simulations of transient water flow and solute transport were performed using the SWAP computer program for 10 layered soil profiles, composed of materials ranging from gravel to clay. In particular, sensitivity of the results to the thickness and position of weakly permeable soil layers was carried out. Daily weather data set from Gda´nsk (northern Poland) was used as the boundary condition. Two types of cover were considered, bare soil and grass, simulated with dynamic growth model. The results obtained with unsteady flow and transport model were compared with simpler methods for travel time estimation, based on the assumptions of steady flow and purely advective transport. The simplified methods were in reasonably good agreement with the transient modelling approach for coarse textured soils but tended to overestimate the travel time if a layer of fine textured soil was present near the surface. Thus, care should be taken when using the simplified methods to estimate vadose zone travel time and vulnerability of the underlying aquifers.

  • Numerical analysis of size effect in RC beams scaled along height or length using elasto-plastic-damage model enhanced by non-local softening.
    • Ireneusz Marzec
    • Andrzej Tejchman-Konarzewski
    • Zenon Mróz
    2019 Full text FINITE ELEMENTS IN ANALYSIS AND DESIGN

    Artykuł omawia wyniki numeryczne dotyczące efektu skali w belkach żelbetowych uzyskane stosując metodę elementów skończonych. Dwuwymiarowe obliczenia wykonano dla belek żelbetowych podczas 4-punktowego zginania. Belki były skalowane wzdłuż wysokości lub długości. Beton został opisany prawem sprężysto-plastycznym z degradacją sztywności, rozszerzonym o nielokalność w osłabieniu. Wyniki numeryczne zostały porównane z wynikami doświadczalnymi. Uzyskano bardzo dobrą zgodność między wynikami numerycznymi i doświadczalnymi.

  • Numerical Analysis of TB32 Crash Tests for 4-cable Guardrail Barrier System Installed on the Horizontal Convex Curves of Road
    • Krzysztof Wilde
    • Dawid Bruski
    • Marcin Budzyński
    • Stanisław Burzyński
    • Jacek Chróścielewski
    • Kazimierz Jamroz
    • Łukasz Pachocki
    • Wojciech Witkowski
    2019 Full text INTERNATIONAL JOURNAL OF NONLINEAR SCIENCES AND NUMERICAL SIMULATION

    Horizontal curves are one of the elements of road infrastructure where statistically a relatively high number of accidents have been reported. In the last ten years in Poland approx. 10% of all road accidents happened on horizontal curves of roads and was responsible for approx. 14% of all fatalities on Polish roads. Thus, this issue is important and requires extensive research and proper road safety treatments. One possible measure that may contribute to improvement of safety on road curves may be barriers. The purpose of this work is to assess, with use of numerical simulations, the performance of the 4-cable barrier systems installed on horizontal road convex curves. The most important parameters for road safety barriers are presented including the effect of various impact velocities and the radiuses of the road curves.

  • Numerical analysis of the container vessel's self-propulsion at different rudder deflection angles
    • Radosław Kołodziej
    • Wawrzusiszyn Michał
    • Bielicki Sebastian
    2019

    Nowadays, CFD becomes one of the most commonly used research method in ship hydrodynamics, limited to the analyses of hull resistance in calm water. With continuously improving computing power and increasingly more accurate numerical methods it is possible to simulate more complex cases. State of the art CFD tools also enable development of new ways of assessing ship maneuvering performance. This paper presents an attempt on using CFD for evaluation of the coefficients used in the formulation of rudder forces applied in the ship manoeuvring model. These coefficient are normally evaluated in captive tests of the hull with working propeller and rudder deflected at different angles; the paper presents the results of CFD simulation of this kind of experiment. The test case used in the analyses is the well known the KRISO Container Ship (KCS). The computations were carried out at model scale 1:50, for which the reference model test results are available. Comparison of CFD and experimental results is presented.

  • Numerical investigation of multiphase blood flow coupled with lumped parameter model of outflow
    • Bartłomiej Melka
    • Wojciech Adamczyk
    • Marek Rojczyk
    • Marcin Nowak
    • Maria Gracka
    • Andrzej J. Nowak
    • Adam Golda
    • Ryszard Białecki
    • Ziemowit Ostrowski
    2019 INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW

    Purpose The purpose of this paper is the application of the computational fluid dynamics model simulating the blood flow within the aorta of an eight-year-old patient with Coarctation of Aorta. Design/methodology/approach The numerical model, based on commercial code ANSYS Fluent, was built using the multifluid Euler–Euler approach with the interaction between the phases described by the kinetic theory of granular flow (KTGF). Findings A model of the blood flow in the arches of the main aorta branches has been presented. The model was built using the multifluid Euler–Euler approach with the interaction between the phases described by the KTGF. The flow and pressure patterns, as well as the volumetric concentration of the blood components, were calculated. The lumped parameter model was implemented to couple the interaction of the computational domain with the remaining portion of the vascular bed. Originality/value The multiphase model based on the Euler–Euler approach describing blood flow in the branched large vessel with a three-element Windkessel model in the coarcted geometry was not previously described in the literature.

  • Numerical investigation of the core eccentricity effect on wave propagation in embedded waveguide
    • Beata Zima
    • Rafał Kędra
    2019 Full text Diagnostyka

    The paper presents results of theoretical and numerical investigation of guided wave propagation in two-layer bars with geometric imperfections in the form of eccentric location of steel core. Steel rod of diameter equal to 1 cm embedded in composite mortar-type cover with external diameter equal to 5 cm has been taken into consideration. Several different rods with variable size of eccentricity are analysed. Results for rods with misalignment of the cover and the core are presented as dispersion curves which were calculated using SAFE method (semi-analytical finite element) and compared with results obtained for perfect axisymmetric rod. Moreover, numerical calculation for several cases of imperfect rods were conducted and results given in the form of displacements and accelerations maps and time-domain signals.

  • Numerical investigation on dynamic response of a steel lattice tower under various seismic events
    • Tomasz Falborski
    • Natalia Lasowicz
    2019

    The present paper presents the results of the numerical study designed to investigate the soil-structure flexibility effects on modal parameters (i.e. fundamental frequencies) and time-history analysis response (represented by the top relative displacements) of a 46.8 m high steel lattice tower subjected to a number of ground motions including also one mining tremor. In addition to the fixed-base condition, three different soil types (i.e. dense soil, stiff soil, and soft soil) were considered in this investigation. Site conditions were characterized by their average effective profile velocities, Poisson’s ratios, and finally mass densities. Soil-foundation flexibility was introduced using the spring-based approach, utilizing foundation springs and dashpots. The first step was to investigate the influence of different base conditions on modal parameters of the steel lattice tower. In the final part of the current study time-history analysis was performed using different two-component ground motion records (in two horizontal, mutually perpendicular directions). The results obtained indicate that modal parameters and dynamic response of the structure may be considerably affected by the soil-structure interaction effects. Therefore, the present paper confirms the necessity of utilizing soil-flexibility into numerical research.

  • Numerical investigation on the performance of a small counter-rotating wind turbine
    • Michał Pacholczyk
    • Krzysztof Blecharz
    • Dariusz Karkosiński
    2019 Full text E3S Web of Conferences

    The article presents the results of the investigation on the performance of a small counter-rotating wind turbine. The wind turbine has been simulated using Computational Fluid Dynamics methods. Actuator Line Model has been successfully used to represent rotors in the computational domain. A parametric study has been carried out, taking into account changes in the tip speed ratio of the rotors while maintaining a constant distance between upwind and downwind rotor. Study results revealed a noticeable increase in power coefficient for optimal configuration. Dynamic interaction between rotors has been investigated exposing no significant interference in both torque and power.

  • Numerical modeling and experimental validation of full-scale segment to support design of novel GFRP footbridge
    • Jacek Chróścielewski
    • Tomasz Ferenc
    • Tomasz Mikulski
    • Mikołaj Miśkiewicz
    • Łukasz Pyrzowski
    2019 Full text COMPOSITE STRUCTURES

    The paper contains analysis of full-scaled three meters long segment of a novel composite footbridge. Both numerical modeling and experimental validation were performed. Analyzed object is a shell type sandwich channel-like structure made of composite sandwich with GFRP laminates as a skin and PET foam as a core. Several static load schemes were performed including vertical and horizontal forces. In FEM analysis multilayered laminate was modeled by means of Equivalent Single Layer (ESL) method while the foam was assumed as three-dimensional continuum. Results were compared with the ones obtained from experiments. Good agreement in comparison showed the correctness of conducted assumption what was a great support in designing process of fourteen-and-half meters long footbridge.

  • Numerical modeling of exciton impact in two crystalographic phases of the organo-lead halide perovskite (CH3NH3PbI3) solar cell
    • Damian Głowienka
    • Jędrzej Szmytkowski
    2019 Full text SEMICONDUCTOR SCIENCE AND TECHNOLOGY

    To improve the power conversion efficiency of solar cells based on organo–lead halide perovskites, a detailed understanding of the device physics is fundamental. Here, a computational analysis of excitons impact is reported for these types of photocell. Numerical calculations based on the model, which take into account electronic charge carriers (electrons and holes), excitons and ions, have been carried out. The role of excitons in two crystallographic phases associated with different temperatures (80 K and 295 K) have been studied with the Saha relation, which clearly distinguishes a domination of free charge carriers or excitons. We have confirmed that excitons prevail in the orthorombic phase. Our work provides information about the photophysics of the lead halide perovskite, which allows for a better understanding of the operation of devices based on perovskite materials.

  • Numerical Modelling of Shear Localization in Granular Bodies using MPM and Non-local Hypoplasticity
    • Jakub Krzyżanowski
    • Michał Wójcik
    • Andrzej Tejchman-Konarzewski
    2019 Full text AIP Conference Proceedings

    The paper deals with modelling of shear localization in granular bodies by means of an enhanced hypoplastic constitutive model and material point method (MPM). The calculations were carried out for plane strain compression of non-cohesive sand. In order to properly capture the width and inclination of shear zones, the constitutive model was enriched by a characteristic length of micro-structure by means of a non-local theory. The approach offered a good correspondence between numerical results and experimental ones.

  • NUMERICAL SIMULATIONS OF HONING PROCESS OF THIN WALL CYLINDER LINERS, WITH CONSTANT AND WITH VARIABLE THICKNESS OF WALL OF HONED PARTS
    • Piotr Sender
    2019

    Numerical simulations of honing process of thin-wall cylinder liners, with constant and with variable thickness of the wall of honed workpieces can improve and can help to conduct the experimental research of honing process and can improve the honing process. A very valuable research assumption, before performing the numerical analysis of computer simulation of honing process, is the measurement of the real geometry of the honing head using a CNC coordinate measuring machine and measuring of the honed workpiece’s temperature occurring in the honed workpiece during honing process with a thermal infrared camera. Thick-walled workpieces do not create machining and technological performance problems. In a predictable way, it’s possible to plan the machining time remaining to receive the desired diameter of the hole being honed. Deformations of a thin-walled workpiece with varying wall thickness occurring during honing, which were measured after machining, showed that there is no linear correlation of holes deformation received for a different crosssection thicknesses of wall of honed cylinder liners for various oilstone pressure and due to the workpiece temperature increase.

  • Numerical simulations of overflow experiments on a model dike
    • Witold Tisler
    • Wioletta Gorczewska-Langner
    • Rafał Ossowski
    • Marcin Cudny
    • Adam Szymkiewicz
    2019 Full text MATEC Web of Conferences

    Dike failure due to overtopping is one of the important factors, which should be considered in the dike designing process. Although the overflow is characterized by the relatively low risk of occurrence, in many cases dikes are totally destroyed or seriously damaged. An interesting phenomenon occurring during overflow is the trapping of air in pores of the unsaturated soil material. As the infiltration progresses from all sides, the air pressure in the unsaturated region increases, which may ultimately lead to damage of the dike structure. It happens when the air is expulsed in form of bursts and forms large macropores. Such a behaviour evidenced in laboratory experiments. In this study we attempt to simulate the evolution of stress field in the model dike subjected to overtopping. The results are in qualitative agreement with observations, showing that formation of the first macropores occurs in the direction perpendicular to the minor principal stress in the soil mass along the dike slope edge.

  • Numerical Study on Mitigation of Flow Maldistribution in Parallel Microchannel Heat Sink: Channels Variable Width Versus Variable Height Approach
    • Ritunesh Kumar
    • Gurjeet Singh
    • Dariusz Mikielewicz
    2019 JOURNAL OF ELECTRONIC PACKAGING

    Microchannel heat sink on one hand enjoys benefits of intensified several folds heat transfer performance but on the other hand has to suffer aggravated form of trifling limitations associated with imperfect hydrodynamics and heat transfer behavior. Flow maldistribution is one of such limitation that exaggerates temperature nonuniformity across parallel microchannels leading to increase in maximum base temperature. Recently, variable width channels approach had been proposed by the current authors to mitigate the flow maldistribution in parallel microchannels heat sinks (MCHS), and in the current numerical study, variable height approach is opted for flow maldistribution mitigation. It is found that variable height microchannels heat sinks (VHMCHS) approach mitigates flow maldistribution rapidly in comparison to variable width microchannels heat sinks (VWMCHS) approach, almost 50% computational time can be saved by VHMCHS approach. Average fluid-solid interface temperature fluctuation across parallel microchannels reduces 3.3 degrees C by VHMCHS in comparison to VWMCHS approach. The maximum and average temperatures of the base of the heat sink are further reduced by 5.1 degrees C and 2.7 degrees C, respectively, for the VHMCHS. It is found that overall heat transfer performance of the heat sink improves further by 3.8% and 5.1% for the VWMCHS and VHMCHS, respectively. The pressure drop penalty of the VHMCHS is found to be 7.2% higher than VWMCHS.

  • Numerically efficient algorithm for compact microwave device optimization with flexible sensitivity updating scheme
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2019 Full text INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING

    An efficient trust-region algorithm with flexible sensitivity updating management scheme for electromagnetic (EM)-driven design optimization of compact microwave components is proposed. During the optimization process, updating of selected columns of the circuit response Jacobian is performed using a rank-one Broyden formula (BF) replacing finite differentiation (FD). The FD update is omitted for directions sufficiently well aligned with the recent design relocation. As the algorithm converges, the alignment threshold is gradually reduced so that the condition for using BF becomes less stringent. This allows for further reduction of the number of EM simulations involved in the optimization process. The presented flexible Jacobian update scheme allows for considerable reduction of the computational cost with only slight degradation of the design quality. Robustness of the presented algorithm is validated through multiple optimization runs from random initial designs. The verification experiments are conducted for a range of microwave components, including a compact microstrip coupler as well as a threesection compact microwave resonant cell-based impedance transformer. The effects of the alignment threshold value on the computational efficiency of the algorithm and the design quality are investigated. Significant savings reaching 50% as compared to the reference algorithm are demonstrated.