Wyniki wyszukiwania - Biblioteka Nauki

1

Badania eksperymentalne aktywnego uszczelnienia czołowego

100%

Michalski D.

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tom Z. 7

91-96

PL

Uszczelnienia aktywne, jako konstrukcje mechatroniczne, są konstrukcjami nowymi i oryginalnymi, dotychczas niestosowanymi w przemyśle. Nieliczne są próby eksperymentalnych badań takich uszczelnień. W niniejszej publikacji pokazano wyniki przeprowadzonych badań eksperymentalnych nowej konstrukcji bezstykowego uszczelnienia czołowego z układem automatycznej regulacji wielkości szczeliny.

EN

Active face seals, as mechatronics constructions, they are new and original, no used in industry. Few tests of experimental investigations of such seals are. The results in present publication were showed the conducted experimental investigations of new construction noncontacting active face seal with automatic clearance control.

2

Badania eksperymentalne bezstykowego uszczelnienia czołowego

63%

Michalski D. , Kundera C.

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2008

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tom Z. 10, Vol. 2

65-72

PL

W artykule opisano sposób przeprowadzenia badań eksperymentalnych mechanicznego bezstykowego uszczelnienia czołowego o konstrukcji typu FMS. Przedstawiono opis stanowiska badawczego oraz wybrane charakterystyki dynamiczne badanego uszczelnienia.

EN

The results in present publication were showed the conducted experimental investigations of the FMS type Noncontacting mechanical face seal. It the description of test ring was introduced was as well as the chosen profiles of studied seal.

3

Ocena właściwości eksperymentalnego modelu bezstykowego uszczelnienia czołowego

63%

Kundera C. , Michalski D.

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tom R. 51, nr 6

20--22

PL

Praca zawiera wstępne badania eksperymentalne bezstykowego uszczelnienia czołowego. Opisano oryginalne stanowisko badawcze, które między innymi umożliwia zmianę siły dociskowej pierścienia uszczelnienia oraz bezpośredni pomiar wysokości szczeliny. Wyznaczono charakterystyki statyczne oraz skokowe badanego uszczelnienia. Otrzymane charakterystyki statyczne posiadaja pętle histerezy z siłą tarcia. Stwierdzono na charakterystykach skokowych, że im większa siła docisku tym mniejsze wzmocnienie i większa stała czasowa. Otrzymane wyniki dowodzą, że system uszczelnienia bezstykowego jest układem nieliniowym.

EN

In this paper are contain the experimental investigations of the noncontacting face seal. The original test rig is described. This test rig is enable the change of the loading force acting on the seal rings and directly measure the seal clearance. The static characteristic and step response of the seal system are determined. the static characteristics shows the hysteresis loop with the friction force. The step responses of the seal clearance indicate that a larger input step size of the closing force gives a smaller gain and larger time constant. Results obtained from the experiments are prove, that the seal system is nonlinear.

4

The Impact of Automation of Air Defence Upon the Effectiveness of Combating Air Assault Assets

63%

Radomyski A. , Michalski D.

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2018

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tom Vol. 42, No. 4

43--58

EN

The article presents the results of studies which focus on theoretical and empirical aspects of the application of automated systems of command in air defence, including the impact of automation on the efficiency of the process of command and the efficiency of using firearms in case of an aerial threat. The presented findings of proper research identify desirable characteristics which automated systems of command should feature. Apart from the theoretical aspects of implementation of modem technical systems as tools to support commanders in information and decision-making processes, attention was also drawn to their role, impact and relevance on the efficiency of combating military air assault assets. The study also uses the knowledge of experts in the field of air defence, especially at the stage of verifying the directions of development of automated systems to support air defence command. In this regard, the authors focused on the possibility of shortening the process of collection, processing, analysis and transmission of data. It constituted the basic determinant of making quick and rational decisions regarding the optimal use of weapons by commanders.

5

Genetic algorithms in pseudorandom testing of medical digitalcircuits

63%

Chodacki M. , Michalski D.

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2009

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tom Vol. 13

209--214

EN

In this paper the problem of unsatisfactory diagnostic efficiency of pseudorandom testing (PRT) technique used to detect faults of digital circuits in testing medical systems of critical importance is presented. The simulations have revealed a weakness of commonly used PRT technique that generally does not assure that all stuck at faults are detected. Thus, it is suggested that PRT technique should be supplemented with additional deterministic testing sequences to enhance fault detection. To design built-in selftesting (BIST) structures a genetic algorithm and digital system stochastic model were used. By employing the stochastic model it is possible to reduce considerably the computer simulation time required for BIST architecture design. In particular, an effect of proportional and ranking selections on the convergence of genetic algorithm in searching for a globally optimal solution, while maintaining the diversity of the population of individuals and limiting its premature stagnation.

6

Badania analityczne rozkładu ciśnienia w przepływie polimeru przy użyciu modelu Ostwalda-de Waele w kanałach stożkowych

51%

Michalski D. , Walicki E. , Walicka A. , Jurczak P.

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2006

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tom Nr 6s

154-156

EN

Flow of molten polymer in conical channels is considered in the paper. To describe the problem a model of viscoplastic fluid is used and the results obtained are illustrated by Ostwald - de Waele fluid flow. The dimensionless formulae for pressure distributions in conical annular channels with inertia effects are presented.

7

Badania teoretyczne nad przepływem zawiesiny opisanej modelem potęgowym w krzywoliniowym kanale z porowatą wkładką

51%

Jurczak P. , Walicka A. , Walicki E. , Michalski D.

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2006

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tom Nr 6s

99-101

EN

Inertia effects in the flow of suspension modelled as a power-law fluid in a curvilinear squeeze film channel with the porous pad were considered. The analysis was based on the assumption that the porous pad consisted of a system of capillaries of very small radii, which allowed the use of the Darcy law and the Mor-gan-Cameron approximation for the flow in the porous pad. A spherical channel was discussed as an example.

8

Efekty bezwładnościowe w przepływie zawiesiny opisanej modelem płynu z naprężeniami momentowymi przez kanał z porowatą wkładką

51%

Jurczak P. , Walicka A. , Walicki E. , Michalski D.

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2006

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tom Nr 6s

101-103

EN

The flow of couple stress fluid in the clearance of a curvilinear channel with the porous pad was considered. The porous pad was connected with the upper impermeable rotating surface approaching the lower fixed channel surface. The Reynolds and Poisson equations were uncoupled using the Morgan-Cameran approximation and closed-form solution was obtained, As an example the channel formed by two disks was discussed.

9

Badania analityczne rozkładu ciśnienia w przepływie polimeru przy użyciu modelu płynu Binghama w kanałach stożkowych

51%

Michalski D. , Walicki E. , Walicka A. , Jurczak P.

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2006

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tom Nr 6s

152-154

EN

Flow of molten polymer in conical channels is considered in the paper. To describe the problem a model of viscoplastic fluid is used but the final results are illustrated by Bingham fluid flow. The dimensionless formulae for pressure distributions in conical annular channels with inertia effects are presented.

10

Pomiary drgań metalowej płyty ze stopu Hastelloy X

51%

Strąk D. , Mięsikowska M. , Piasecka M. , Michalski D.

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tom Nr 59

183--186

PL

Celem artykułu jest pomiar drgań metalowej płyty ze stopu Hastelloy X i ich analiza. Badania przeprowadzono z wykorzystaniem wzbudnika magnetycznego własnej konstrukcji oraz wibrometru laserowego PSV-500. Wprowadzenie płyty w drgania o różnej częstotliwości ma na celu wytworzenie sytuacji fizycznej podobnej do występującej na powierzchni grzejnej wymiennika ciepła. W pracy przedstawiono konstrukcję stanowiska badawczego i metodykę przeprowadzenia eksperymentów. Zarejestrowane sygnały analizowano w dziedzinie czasu i częstotliwości.

EN

The aim of this article is to measure vibrations of a metal plate of Hastelloy X alloy and its analysis. The research was performed using a magnetic inductor of authors design and a laser vibrometer PSV-500. The introduction of the plate into vibrations of different frequencies is aimed at creating a physical situation similar to that occurring on the heating surface of the heat exchanger. The work presents the construction of the test stand and the methodology of performing the experiments. The recorded signals were analyzed in terms of time and frequency domain.

11

Flow of a couple-stress fluid in a curvilinear thrust bearing with one porous pad

51%

Jurczak P. , Walicka A. , Walicki E. , Michalski D.

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tom nr 3

63-75

EN

The flow of a couple stress fluid in the clearance of a curvilinear bearing with a porous pad is considered. The porous pad is connected with the upper impermeable rotating surface which approaches the lower fixed bearing surface. The Reynolds and Poisson equations are uncoupled by using the Morgan-Cameron approximation and a closed-form solution is obtained. As an example the bearing formed by two disks is discussed.

PL

W pracy rozważono przepływ płynu z naprężeniami momentowymi w krzywoliniowej szczelinie łożyska z porowatą wkładką. Porowata wkładka powiązana jest z górną nieprzepuszczalną wirującą powierzchnią, która zbliża się do dolnej nieruchomej powierzchni łożyska. Do rozwiązania równań Poissona oraz Reynoldsa wykorzystano przybliżenie Morgana-Camerona. Jako przykład rozpatrzono łożysko utworzone przez dwie kołowe tarcze.

12

Inertia effects in a curvilinear squeeze film bearing with one porous wall lubricated by a power-law fluid

51%

Walicka A. , Walicki E. , Jurczak P. , Michalski D.

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2003

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tom Vol. 8, no 1

107-116

EN

The flow of a power-law lubricant in a squeeze film bearing with one porous wall is considered. The bearing is modelled by two curvilinear surfaces and the porous wall is adhered to the curved non-porous surface. The flow in the bearing clearance is considered with inertia and the Navier-Stokes and Poisson equations are uncoupled by using the Morgan-Cameron approximation. Using the averaged inertia method the closed-form solution is obtained. A step bearing is discussed as an example.

13

Determining the shift of a bronchoscope catheter from the analysis of a video sequence of a bronchoscope video camera

51%

Michalski D. , Tabor Z. , Zieliński B.

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tom Vol. 37, no. 4

630--636

EN

In this study we have proposed an algorithm for automated monitoring of the movements of a catheter used in peripheral bronchoscopy examination. We have shown that the shift of the catheter can be controlled in an automated way with quite a good accuracy by the means of analysis of video sequence recorded by a video camera of a bronchoscope. For a catheter moving between successive frames by no more than 1/3 of the distance between successive markers associated with a catheter the accuracy of a catheter shift measurement was equal to 1% and for a catheter moving between successive frames by no more than 1/2 of the distance between successive markers associated with a catheter the accuracy of a catheter shift measurement was equal to 5%. Visual inspection proved that the observed measurement errors were associated with faster movements of a catheter. Bronchoscope redesign option is proposed to improve catheter shift measurement accuracy. The results of this study demonstrate that application of image analysis techniques to data recorded during bronchoscopy examination can at least support the existing navigation methods for peripheral bronchoscopy with respect to the determination of the location of the catheter distal tip within the lumen of the pulmonary airways.

14

The study of pressure drops in the flow of a polymer modeled as a bingham fluid in conical channels

51%

Michalski D. , Walicki E. , Walicka A.

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tom Vol. 11, no 2

359-369

EN

Technologies applied in polymers processing are permanently improved due to updating the knowledge on material proprieties, processes and phenomena during the processing. To determine the pressure distribution, one should define the geometrical shape of a channel, in the flow will be held the flow. The aim of calculations carried out is to determine the possibility of mathematical modelling of polymer flows between conical parallel surfaces. In this work, the flow of a polymer in conical channels was considered. To describe a melted polymer the model of a viscoplastic fluid was used but final results were illustrated by a flow of the Bingham fluid. The Bingham fluid chosen to modelling the flow of a polymer may by considered as legitimate, because its use will allow us to illustrate analytical methods of calculations. For the flow configuration and model under consideration the geometrical sizes of the channel and material coefficients of the fluid will be chosen on the basis of experimental data contained in literature. In the article, the on defining dimensionless pressure distribution for the flow in a conical channel as well as in a conical annular channel with the influence of inertia were presented. The results of calculations were introduced in tabular forms as well as in graphic forms.

15

Influence of rheological parameters on the mechanical parameters of curvilinear thrust bearing with one porous wall lubricated by a couple stress fluid

51%

Jurczak P. , Walicka A. , Walicki E. , Michalski D.

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tom Vol. 11, no 2

221-233

EN

The flow of a couple stress fluid in the clearance of a curvilinear thrust bearing with a porous pad is considered. The porous pad is connected with an upper impermeable rotating surface which approaches the lower fixed bearing surface. The Reynolds and Poisson equations are uncoupled by using the Morgan-Cameron approximation and a closed-form solution is obtained. Expressions for the pressure and capacity load of the bearing are given. As an example the bearing modelled by two disks and two spherical surfaces is discussed.