Wyniki wyszukiwania - BazTech

1

New Photometric and Spectroscopic Observations of the Eclipsing Binary V2080 Cygni

Dimitrov W., Kamiński K., Bąkowska K., Kamińska M. K., Tokarek J., Pawłowski M., Boneva D., Bartczak P., Kwiatkowski T., Schwarzenberg-Czerny A.

Acta Astronomica

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2022

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Vol. 72, No. 1

55--67

EN

We present new spectroscopic and photometric measurements of the eclipsing binary V2080 Cyg. It is a detached system with similar components and an orbital period of 4.9 d. We collected spectroscopic data with two instruments, 1.88 m DDO telescope equipped with Cassegrain spectrograph and 0.5 m PST1 connected to a fiber-fed echell\'e spectrograph. We collected 127 measurements for each component, which significantly increase the number of available radial velocity measurements for the V2080 Cyg system. Obtained masses of the eclipsing components are M1=1.189± 0.007 and M2=1.138±0.007 M☉. We also collected a multicolor photometry. The three-band light curves obtained together with the radial velocity data enabled us to calculate the model of the system. New estimations of the orbital inclination and radii of the components were computed. We obtained as well new times of minima. The O-C diagrams indicate variation, which requires more recent data to be confirmed. The possible existence of a third body could cause a light-time effect in the system. In addition, we analyze the Gaia mission results. V2080 Cyg A has three visual companions. However, according to Gaia parallaxes and proper motions, they cannot be dynamically connected with the eclipsing binary and therefore are background stars.

2

Instability issues in the server room cooling system

Kwiatkowski T., Prusiński P., Zgorzelski D., Kozioł S

Journal of Power Technologies

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2017

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Vol. 97, nr 3

252--258

EN

Since 2009, the National Center for Nuclear Research in Poland has been constructing its own High Performance Computing (HPC) Centre under the name Świerk Computing Centre (CIŚ). Now, it is ready reaching its target - 1 PFLOPS - in December 2015. However at the early operation stage, one of its major problems was the unstable work of the HPC cluster cooling system, resulting in increased maintenance costs. The main aim of this work is to thoroughly investigate the origin of the problem and to find the best solution for it based on results from a Computational Fluid Dynamics (CFD) analysis. The constructors suspected that the oscillations in the flow domain are caused by thermal flow stratification, but something else was proved. In this paper, a wide range of cases will be analyzed, covering different work regimes of the installation as well as various geometry modifications. Finally, certain improvement to the current design will be suggested by the CFD Analysis Group.

3

Nowoczesne przekrycia z dachowych tkanin membranowych

Kwiatkowski T., Patrzykowski M.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2016

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Z. 22 (172)

196-203

PL

W pracy omówiono zalety stosowania nowoczesnych tkanin technicznych, do których należą przekrycia membranowe. Przedstawiono charakterystykę konstrukcji, gdzie wykorzystywano tego typu tkaniny. Podano liczne przykłady wykorzystania tkanin membranowych w Polsce i na świecie

EN

The paper presents the advantages of using modern technical fabrics which include roof covering membrane. The characteristic design where the use of are the types of fabric. Presents numerous examples of taknin membrane in Poland and in the world.

4

Kleje konstrukcyjne

Kwiatkowski T., Rajczyk M.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2016

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Z. 22 (172)

191-195

PL

W pracy przedstawiono historię zastosowania klejów w zarysie. Zaprezentowano podział klejów i ich wykorzystanie w budownictwie. Zwrócono również uwagę na zasady i technologię wykonywania połączeń klejowych.

EN

The paper presents a historical overview of applicability of adhesives and classification of adhesives and their use in construction. It also presents the principles and technology of making glue joints.

5

Source term model for streamwise Rod Vortex Generator modelling

Kwiatkowski T., Flaszyński P.

Journal of KONES

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2016

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Vol. 23, No. 4

261--268

EN

In the article, the new method of modelling of Rod Vortex Generators (RVGs) was proposed. RVGs are inclined rods, mounted in boundary layer used to flow control. RVGs were intensively investigated in Institute of Fluid-Flow Machinery in Gdansk, Poland. The research results indicate high potential of RVGs to flow control in wide range of Mach numbers (Mach 0.3-1.45) in the main flow. Due to the flow structure details generated by RVG, it is required to create fine grids in the vicinity of RVGs, which increase the computational cost. In order to overcome this difficulty and reduce computational cost the new numerical models of RVGs are proposed, which use the modification of BAY model. Using BAY model it is not needed to resolve the shape of RVG in detail and it is possible to use orthogonal meshes. The BAY model was originally proposed to predict flows behind thin-plate vortex generators. This model works by adding momentum source term to Reynolds-Averaged Navier-Stokes equations in ANSYS Fluent. The BAY model spatial vectors orientation was modified and some simplifications were performed. The model was calibrated and simulations were carried out for the single rod. The results and effectiveness of modified BAY model were compared with wind-tunnel experiment results and grid-resolved model.

6

Analysis of effects of shape and location of micro-turbulators on unsteady shockwave-boundary layer interactions in transonic flow

Sznajder J., Kwiatkowski T.

Journal of KONES

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2016

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Vol. 23, No. 2

373--380

EN

Solutions for turbulisation of a part of laminar boundary layer upstream of shockwave on laminar airfoil in transonic flow were investigated by means of solution of Unsteady Reynolds-Averagd Navier-Stokes equations using as a closure the four-variable Transition SST turbulence model of ANSYS FLUENT solver. This turbulence model has the capability of resolving laminar-turbulent transition occurring in undisturbed flow as well as under the influence of flow-control devices. The aim of the work was to investigate possibilities of improvement of aerodynamic characteristics of laminar wing of a prospective transport aircraft in adverse conditions characterised by occurrence of a shockwave over a laminar-turbulent transition region with separation of laminar flow under the shockwave. The subject is important for application of laminar flow technology, offering economic and environmental advantages due to decreased friction drag, into civil transport aviation. Natural laminar-turbulent transition in the investigated conditions takes place with occurrence of “laminar separation bubble” under the foot of a shockwave and the resulting shockwave is intensive and prone to unsteady oscillations, the “buffet” phenomenon, limiting operational range of flight parameters. In order to counteract the harmful effects of natural laminar-turbulent transition in transonic flow two types of turbulators, placed upstream of the shockwave, were investigated. One of them consisted of delta-shaped vortex generators, producing chordwise-oriented vortices. The other consisted of rectangular micro-vanes, perpendicular to flow and to airfoil surface producing vortices of rotation axes oriented spanwise. Effectiveness of both types of turbulators was investigated for varying height and their location on airfoil chord. Both types of turbulators have proved their effectiveness in tripping laminar boundary layer. The specific effects of the tutbulators, different for each type occurred in the region where laminar separation takes place on clean airfoil. As a result, the changes of lift and drag were different for each type of turbulators.

7

Kotwy chemiczne : zalety, rodzaje i obszar zastosowania

Kwiatkowski T.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2015

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Z. 21 (171)

177--182

PL

W pracy przedstawiono kotwy chemiczne. Zaprezentowano ich podział, zalety w porównaniu z kotwami mechanicznymi oraz obszary ich wykorzystania. Omówiono też rozwiązania systemowe, w których wykorzystano kotwienie chemiczne.

EN

In the paper there were presented chemical dowels. It describes their division, their advantages in comparison to mechanical anchors and areas of their use. The article also includes system solutions that use chemical anchoring.

8

Selected aspects of introduction of a laminarflow wing into transport aviation

Sznajder J., Kwiatkowski T.

TTS Technika Transportu Szynowego

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2015

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R. 22, nr 12

1486--1489, CD

EN

The paper presents results of numerical simulation of turbulization of boundary layer interacting with a shock-wave on laminar airfoil in transonic flow. Three configurations were tested using a “2.5-dimensional” flow model: baseline configuration of clean airfoil and two configurations using microvortex generators submerged in the airfoil boundary layer in front of the shockwave. Unsteady Reynolds-Averaged Navier-Stokes equations were solved using as a closure a fourequation turbulence model capable of resolving laminar-turbulent transition. It was shown that microvortex generators submerged in the boundary layer are capable of eliminating flow separation zone at the foot of the shockwave and in effect, of achieving lower aerodynamic drag at the same lift force that occuring at natural laminar-turbulent transition at the shockwave.

PL

W artykule przedstawiono wyniki numerycznej symulacji turbulizacji warstwy przyściennej oddziałującej z falą uderzeniową w przypadku laminarnego profilu lotniczego w opływie transonicznym. Badano trzy konfiguracje stosując „2.5 wymiarowy” model opływu: konfigurację podstawową obejmującą gładki profil i dwie konfiguracje w których zastosowano miniaturowe generatory wirów w warstwie przyściennej przed falą uderzeniową. Wykazano że miniaturowe generatory wirów o kształcie "delta” umieszczone w warstwie przyściennej są w stanie wyeliminować strefę oderwania opływu pod falą uderzeniową i w efekcie uzyskać mniejszy opór aerodynamiczny przy tej samej sile nośnej co w przypadku swobodnego przejścia laminarno-turbulentnego na fali uderzeniowej.

9

Sprawność systemów automatycznego rozpoznawania tablic rejestracyjnych pojazdów w aplikacjach ITS

Rychlicki M., Kwiatkowski T., Kasprzyk Z.

Logistyka

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2015

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nr 4

888--897, CD1

PL

W pracy przedstawiono wyniki badań, których celem była ocena sprawności systemów automatycznego rozpoznawania tablic rejestracyjnych oraz określenie, jaki wpływ na tę sprawność mają parametry obrazu. Przedstawiono wyniki własnych badań oraz dokonano analizy wpływu poszczególnych parametrów obrazu na sprawność systemu rozpoznawania tablic rejestracyjnych. Przedstawiono również najczęściej występujące błędy odczytu znaków tablic, które uniemożliwiły poprawne ich rozpoznanie podczas trwania badań. Omówiono także wpływ parametrów obrazu na wielkość pliku, co ma szczególne znaczenie podczas projektowania systemów ANPR oraz ich eksploatacji, w odniesieniu do łącza transmisyjnego.

EN

The paper presents of a review and the characteristics of modern methods of vehicle registration plate recognition in the ITS applications. The nature of the problem has been indicated, which consists in the fact that suppliers of the ANPR systems overrate the efficiency of the number plate recognition. The results presented in the paper allow us to conclude that the efficiency of ANPR systems depends largely on the image resolution applied but only to a certain limit.

10

Effects of turbulence induced by micro vortex generators on shockwave : boundary layer interactions

Sznajder J., Kwiatkowski T.

Journal of KONES

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2015

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Vol. 22, No. 2

241--248

EN

Interactions between viscous and transonic effects in air flow around a laminar wing were investigated computationally by means of the solution of unsteady Reynolds-averaged Navier-Stokes Equations. The subject is important from the point of view of applications of Natural Laminar Flow technology in modern, economically efficient passenger aircraft. The research was focused on simulations and analyses of influence of turbulence induced by micro vortex generators on intensity of harmful transonic phenomena like strong shock waves and buffet. Two ways of modelling of the effects of turbulators – the micro vortex generators were taken into consideration. The first way consisted in resolving the shape and inclination angle of the generator in the grid over airfoil and setting the non-slip wall boundary condition on the surface of the generator. The second way, taking advantage of the BAY model of vortex generator, was implemented on orthogonal grid without the need of resolving the shape of the vortex generator in the grid. Calibration of the BAY model was aimed at producing similar distribution of vorticity and velocity circulation behind the model of the vortex generator, as obtained for the grid-resolved model of the vortex generator. The calibration procedure resulted, however, in overestimated turbulisation of the boundary layer in the BAY model, compared to the effects of the grid-resolved vortex generator. The flow simulations indicated, however, that turbulisation of boundary layer induced by micro vortex generators can reduce or eliminate the oscillation of strong shock wave and buffet in off-design conditions and that further adjusting of the BAY model is an efficient strategy for modelling the interactions between viscous and transonic effects in air flow around a laminar wing.

11

Ogrodzenia metalowe : konstrukcja i konserwacja

Tubielewicz-Michalczuk M., Kwiatkowski T.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2014

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Z. 20 (170)

270--275

PL

W pracy przedstawiono i opisano przykłady ogrodzeń metalowych oraz ich konstrukcje. Zaprezentowano zasadnicze części ogrodzeń kutych, odlewanych, konstrukcji specjalnych, jak również opisano sposoby ochrony przed skutkami oddziaływania warunków atmosferycznych na konstrukcje z metalu.

EN

The paper presents and describes examples of metal fences and their structures. There were presented essential elements of forged and cast fences and special constructions, as well as ways of metal structure protection against the effects of weather conditions.

12

Nowy materiał konstrukcyjny : kompozyt

Kwiatkowski T.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2014

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Z. 20 (170)

127--132

PL

W pracy przedstawiono ogólne zależności obliczania naprężeń w materiałach kompozytowych. Omówiono także ich wykorzystanie w różnych gałęziach przemysłu. Pokazano też przykłady zastosowania taśm węglowych do wzmacniania konstrukcji.

EN

The paper presents general dependences concerning the calculation of stresses in composite materials and their application in different branches of industry. The examples of the carbon tapes applications to construction reinforcement are also shown.

13

The possibilities of assessing the efficacy and comparison of the license plate recognition systems

Rychlicki M., Kwiatkowski T.

Roads and Bridges - Drogi i Mosty

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2014

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Vol. 13, no. 4

393--408

PL

W pracy dokonano przeglądu i charakterystyki współczesnych metod rozpoznawania tablic rejestracyjnych pojazdów. Omówiono ich wysokie i stale rosnące znaczenie dla wykorzystania w systemach inteligentnego transportu. Podkreślono ich duży wpływ na poprawę bezpieczeństwa ruchu oraz rozwój systemów pokrewnych, jak np. ważenia pojazdów w ruchu. Zwrócono uwagę na istniejące problemy w ocenie skuteczności i porównania tego typu systemów. Wskazano istotę problemu, którą jest zawyżana przez producentów oraz dostawców tego typu rozwiązań skuteczność rozpoznawania, deklarowana na poziomie nawet 100%. Z oczywistych powodów musi to rodzić wątpliwości i stwarza problemy praktyczne. Z tego powodu w pracy przedstawiono metodę oceny systemów rozpoznawania tablic, mogącą przyczynić się do ich praktycznego porównania oraz wyznaczenia realnego poziomu skuteczności. Dokonano implementacji metody w aplikacji narzędziowej i przeprowadzono analizę otrzymanych wyników. Zaproponowano projekt stanowiska badawczego, umożlwiającego ocenę tego typu rozwiązań w warunkach laboratoryjnych.

EN

The paper consists of a review and the characteri-stics of contemporary methods of vehicle registration plate recognition. Their high and increasingly growing importance for the use in intelligent transport systems has been discussed. Their large impact on improving traffic safety and the development of related systems, such as weighing vehicles in motion, have been emphasized. Attention has been paid to the existing problems in the evaluation of the effectiveness and comparison of such systems. The nature of the problem has been indicated, which consists in the fact that manufacturers and suppliers of such solutions overrate the effectiveness of the recognition, declared to be even 100%. For obvious reasons, it raises questions and poses practical problems. For this reason, the paper presents a method for assessing the license plate recognition systems, which mightcontribute to their practical comparison and determination of the real level of effectiveness. The implementation of the method in the tool application has been performed and the analysis ofthe obtained results has been carried out. A design of the test stand has been proposed, that would enable the evaluation of such solutions in the laboratory conditions.

14

Przegląd i konserwacja drewnianych kościołów w wybranych regionach Polski

Tubielewicz-Michalczuk M., Kwiatkowski T.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2013

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Z. 19 (169)

204--210

PL

W pracy przedstawiono i opisano obiekty architektury sakralnej w wybranych regionach Polski. Opisano sposoby impregnacji drewna w celu konserwacji architektury drewnianej. Zaprezentowano także podstawowe gatunki drewna do wznoszenia konstrukcji budowlanych.

EN

The paper presents and describes the objects of religious architecture in selected Polish regions. Methods wood treatment in order to preserve the wooden architecture. It also presents the basic types of wood for the construction of building structures.

15

The PSA analysis of PWR emergency coolant injection availability following SBLOCA

Borysiewicz M., Bronowska K., Kopka P., Kowal K., Kwiatkowski T., Prusiński A. M., Prusiński P. A., Siess G.

Nukleonika

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2013

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Vol. 58, No. 2

307--316

EN

The aim of this article is to briefly introduce the probabilistic safety assessment (PSA) of nuclear power plants (NPPs), its scope, main concepts and application to a real case. The results of analysis presented here have been obtained by the Probabilistic Safety Analysis Group (GPSA) at the National Centre for Nuclear Research (NCBJ, Otwock) as a part of the work done for the Polish National Atomic Energy Agency (NAEA). As a reference, NPP Surry Unit 1 (USA), equipped with 800 MWe Westinghouse triple-loop PWR (pressurized water reactor), has been chosen. The emergency coolant injection (ECI) function availability following the small break loss of coolant accident (SBLOCA) was thoroughly analyzed. The approach and data, which were adopted for the selected part of the SBLOCA sequences, were those used in the U.S. NRC Reactor Safety Study (WASH-1400). As a result of this study, the SBLOCA event tree, including ECI systems, i.e. high pressure injection system (HPIS) and auxiliary feedwater system (AFWS) reliability models, was developed and quantified. The probability of each accident sequence was evaluated using Saphire v.8, the PSA software by U.S. NRC. The choice of the software was based on earlier PSA software study. The failure probability of at least one of the considered safety systems – P(FAIL) is equal to 5.76E-3 and the most pessimistic accident branch (unavailability of both HPIS and AFWS) is about 0.05% of P(FAIL). These results were obtained based on assumption that the SBLOCA has occured. The most significant failure components are those corresponding to charging pumps unavailability, loss of electric power and human errors.

16

Scheduling problems with a common due window assignment: a survey

Janiak A., Kwiatkowski T., Lichtenstein M.

International Journal of Applied Mathematics and Computer Science

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2013

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Vol. 23, no. 1

231--241

EN

In this article a survey of studies on scheduling problems with a common due window assignment and earliness/tardiness penalty functions is presented. A due window is a generalization of the classical due date and describes a time interval in which a job should be finished. If a job is completed before or after the due window, it incurs an earliness or a tardiness penalty, respectively. In this survey we separately analyse the classical models with job-independent and job-dependent earliness/tardiness penalty functions and some other more complicated models. We describe the computational complexity of the problems and the main features of the approaches developed to solve them. Particular attention is paid to practical applications of the analysed models. As turns out, some complicated models combining classical scheduling problems with, e.g., learning and aging effects have no reasonable practical justification in the literature.

17

Aluminium w nowoczesnych konstrukcjach budowlanych

Kwiatkowski T.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2012

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Z. 18 (168)

108--115

PL

Tematem niniejszej pracy jest zastosowanie i wykorzystanie aluminium we współczesnym budownictwie i w architekturze. Zaprezentowano niekonwencjonalne konstrukcje istniejących budowli oraz rozwiązania konstrukcji, w których wykorzystano stopy aluminium.

EN

The subject of this paper is the adaptation and the usage of aluminum in the modern building industry and architecture. This work also presents both the unconventional constructions of existing buildings and other constructions, in which the aluminum alloys were used.

18

Modelling a landfill energy potential based on the monitoring investigation results

Kwiatkowski T., Żygadło M.

Structure and Environment

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2012

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Vol. 4, no. 1

43--51

EN

The objective of the investigation was to establish the main variable factors (index parameters) determining the methane production level, using for this propose static modelling with the application of Pearson's correlation coefficient (r) and multiple regression. The waste disposal site in Janik, the municipality of Kunów, was monitored in the years 2008-2011. 16 series of markings were obtained, which were analysed and the findings provided the basis for the investigation. The above mentioned investigation and field observations permitted the creation of database, which was analysed statistically using STATISTICA 10 package.

19

CFD analysis of the safety related thermal hydraulic parameters describing a flow domain of an experimental medical installation (BNCT converter) inside of the Research Reactor MARIA

Prusiński P. A., Potempski S., Borysiewicz M., Kowal K., Kwiatkowski T., Prusiński A. M.

Journal of Power Technologies

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2012

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Vol. 92, nr 4

227--240

EN

The Boron-Neutron Capture Therapy (BNCT) is an experimental radiotherapy technique used to treat the most aggressive types of brain tumors that cannot be surgically removed from the human body. To date, clinical trials of BNCT have been initiated at only a handful of reactors around the world, but advanced studies on BNCT are still being carried out in numerous research centers where the suitable or convertible reactors are available. Construction of BNCT facilities is justified only at some existing reactors. Others can possibly be adapted for BNCT by using fission converters to modify the energy spectrum of the primary neutron beam, which makes it useful for treatment purposes. The BNCT converter, designed for use in the MARIA research reactor at the National Centre for Nuclear Research [W1] (NCBJ) in Świerk near Warsaw, Poland, consists of 99 fuel rods (containing low-enriched uranium) inside of the aluminum box. Since its installation affects the core layout and possibly may affect the normal operating regime of the reactor, additional safety analyses must be performed to prove the existence of sufficient safety margins. In this study modern Computational Fluid Dynamics (CFD) techniques have been applied to assess the maximum temperature of the rod wall surfaces, the temperature difference between the inlet and outlet of the converter channel, as well as the maximum and average velocity of the fluid and to compare them with the results presented in the reference analytical study.

20

Trójwariantowa analiza dynamiczna ramy nośnej dwunawowej hali stalowej

Kwiatkowski T.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2011

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Z. 17 (167)

119-128

PL

Tematem niniejszego artykułu jest trójwariantowa analiza dynamiczna ramy nośnej dwunawowej hali stalowej. Zaprezentowano podział obciążeń dynamicznych, metody redukcji drgań oraz opisano oddziaływanie drgań na organizm człowieka, konstrukcje i urządzenia. W artykule zostały przyjęte trzy schematy statyczne dla dwunawowej hali stalowej o jednakowych gabarytach. Każdemu schematowi narzucone zostały takie same obciążenia, na podstawie których wygenerowano kombinacje normowe za pomocą programu komputerowego. Następnie przeprowadzono analizę modalną dla każdego z trzech schematów. Wszystkie obliczenia zostały przeprowadzone w programie komputerowym firmy Autodesk o nazwie Robot Millenium. Wyniki analiz przedstawiono w formie wykresów. Na podstawie danych z wykresów oraz porównania poszczególnych schematów zostało wybrane najkorzystniejsze rozwiązanie dla ramy nośnej pod względem dynamicznym.

DE

Es wurde eine Einteilung der dynamischen Belastungen, Methode der Reduktion von Schwingungen, sowohl eine Wirkung der Schwingungen auf Menschen, Konstruktionen und Vorrichtungen vorgestellt. Im Rahmen des Bauplanes wurden drei statischen Schemas mit den gleichen Abmessungen für die Stahlhalle ausgewählt. Jedem Schema wurden dieselben Belastungen zugeordnet anhand, dessen wurde eine Normkombination durch ein Computerprogramm erlangt. Dann wird eine Modalanalyse für jeden Schema durchgeführt. Alle Ausrechnungen wurden in einem Computerprogramm Autodesk - Robot Millennium ausgeführt. Die Ergebnisse der Analysen werden in Form von den Diagrammen vorgestellt. Aufgrund der Diagrammen und des Schemavergleiches wurde die günstigste Lösung in dynamischer Hinsicht für tragenden Rahmen gewählt.