Wyniki wyszukiwania - Biblioteka Nauki

1

Variability in the saline water exchange between the Baltic and the Gulf of Gdansk by the sigma-coordinate model

100%

Jankowski A.

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tom No. 45 (1)

81-105

EN

A three-dimensional baroclinic sigma-coordinate model was applied to study the circulation and thermohaline variability in the coastal zone in the south-eastern Baltic Sea. The model is based on the Princeton Ocean Model code of Blumberg & Mellor (1987), known as POM, and has the horizontal resolution of ~5 km and 24 sigma-levels in the vertical. The hydrodynamic conditions and variability of water and salt exchange between the Gulf of Gdansk and the Baltic Proper, and the renewal of water masses in the Gulf of Gdansk due to atmospheric forcing are analyzed. The numerical simulations were performed with real atmospheric forcings as well as with homogeneous (spatially uniform) wind fields over the whole Baltic Sea. The numerical simulations showed that the atmospheric forcing (winds) can play a significant role in shaping the renewal of bottom saline waters in the Gulf of Gdansk. Two regions of inflow/outflow of saline waters responsible for the salinity regime were located. The overall water exchange between the Gulf and the Baltic Proper as well as the exchange of saline bottom waters appear to be strongly dependent on wind conditions. The net flux of water of salinity >9 PSU is of the order of 48000-100000 m3 s-1. SE, E, S and NE winds were found to exert the greatest influence on salinity conditions in the Gulf of Gdansk. Estimates of saline (salinity >9 PSU) water residence time based on the model simulation yielded values from 46 days for SE winds to 153 days for NW winds.

2

Zywoploty

100%

Jankowski A.

|

nr 10

12-13

3

Water mass exchange between the Gulf of Gdansk and the Baltic Sea

100%

Jankowski A.

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1985

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tom 20

4

Modelling of combustion processes of liquid fuels

100%

Jankowski A.

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tom Vol. 19, No. 4

239-244

EN

The modelling of combustion processes of liquid fuels assumes that combustion processes of fuels always occur in gas-phase, gas-phase may be homogeneous or heterogeneous mixture. For homogeneous mixture, course of combustion processes is controlled by kinetics of chemical reactions. For heterogeneous mixture, course of combustion processes is controlled by initial processes, with reference to liquid fuels, vaporization processes of fuel occur. Flow of combustion gases (velocity and kind) intensifies combustion processes, influence of pressure on combustion processes of liquid fuels differs from the influence on combustion processes of gas fuels. The subject of the paper is the modelling of the combustion process of heterogeneous fuels, researches processes of spraying and combustion. The researches of atomization and combustion processes were performed in combustion chamber of the constant volume. To carry out the research, the test equipment was used, which allowed the visualization of atomization and combustion processes by means of the camera to high-speed photographing, measurements of distribution velocity stream atomised fuel with the laser-equipment PIV, LDV and PDPA, and measurement of the pressure in combustion chamber. The model of the combustion process of heterogeneous fuels based on properties of the boundary layer with addition of the mass was worked out.

5

Specjalizacja zawodowa inżynierów zatrudnionych w zakładach przemysłu spożywczego

100%

Jankowski A.

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nr 07

6

Wind-induced variability of hydrological parameters in the coastal zone of the southern Baltic Sea - a numerical study

100%

Jankowski A.

|

tom Vol. 29, No. 3

5-34

EN

Abstract The wind-produced variability of temperature, salinity and velocity in the coastal zone of the southern Baltic Sea have been investigated with the help of a three-dimensional F-coordinate baroclinic model. The model was based on the Princeton Ocean Model code of Mellor (1993), known as POM. The main intention of this study was to reproduce the variability of the hydrological conditions as the response of stratified seawaters to the model atmospheric forcing of three successive storms. Winds of constant speed from eight directions over the Baltic during each storm were considered. The presentation of results is limited to the area along the Polish coasts of the Baltic Sea, where the complicated bottom topography exerts a crucial influence on water movements. The numerical model runs show that winds can play an important role in the water exchange between the coastal region and the open sea, generating intense fluctuations of hydrological parameters. When winds are from the SE, E and NE, coastal upwelling is frequent along the Polish Baltic coast (Bychkova and Victorov 1987, Bychkova et al. 1988, Urbanski 1993). The results calculated with the use of the POM code are in agreement with the results obtained using the z-level model (Krauss and Brügge 1991) and from studies in the Great Lakes and in other upwelling areas (Bennet 1974, Krauss 1979, Fennel 1986).

7

Some effects of applying a new type of pistons for SU12-U diesel engine

100%

Jankowski A.

|

tom Vol. 23, No. 4

167--174

EN

In the task of research and development of internal combustion engines, the strong emphasis is placed on reducing emissions of harmful substances in exhaust gases, which include carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM, PN); while maintaining a high engine performance and, above all, adequate: power, fuel consumption, noise. One of the possibilities to reduce emissions of HC and engine working noise is to reduce the clearance between the piston and the cylinder liner. This is possible only, when the permanent deformations of the piston are reduced, which result from rapid piston temperature changes (thermal shocks). The newly developed composite aluminum alloy is characterized by high strength parameters and low dimensional hysteresis during repeated heating and cooling. The S12-U engine pistons are made of this material, and they had a slightly larger nominal diameter than the standard pistons. They were then mounted in the engine. The engine was tested on a test stand with the modern, accurate measuring equipment. Test results show, that the HC and CO content in the exhaust gas has been reduced, exhaust gas blowby to the crankcase declined, smoke emission was reduced and engine lubricating oil consumption was also reduced. Analysis of test results indicates that this has been achieved, mainly by reducing the clearances between the piston and the cylinder. The article provides detailed test results, mainly in the form of charts, on which one can compare the results, achieved by the engine with new material pistons with results of the same engine, but with the standard pistons.

8

Rough Sets and Interactive Granular Computing

63%

Skowron A. , Jankowski A.

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tom Vol. 147, nr 2/3

371--385

EN

In several papers we have discussed a computing model, called the Interactive Granular Computing (IGrC), for interactive computations on complex granules. In this paper, we compare two models of computing, namely the Turing model and the IGrC model.

9

Influence of fuel quality on mixture preparation and exhaust emissions from diesel engines with common rail system

63%

Jankowski A. , Sandel A.

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tom Vol. 10, No. 3-4

79-92

EN

The objective of mixture preparation process in Diesel engines is obtaining full combustion and minimum harmful compounds of exhaust emissions. The injection process is the most important from the viewpoint of mixture preparation process. The experimental data of fuel spray atomization and droplet velocities of three different fuels with varied viscosity are presented in the paper. The research was performed using the PIV and LDYand PDPA laser equipment. The tested fuels were Diesel oils with varied viscosity and RME. The injection pressure varied from 50 MPa to 130 MPa. The fuels were injected to test chamber with optic access in atmospherical pressure and temperature. Pressure increase caused a continuous reduction in fuel drop diameter. The fuels with higher viscosity generated bigger droplets than the fuel with lower viscosity.

10

Wpływ jakości rozpylenia paliwa na emisję toksycznych składników spalin silników spalinowych

63%

Jankowski A. , Kowalski M.

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tom No. 4 (36)

43--50

PL

W artykule podjęto się analizy wpływu jakości rozpylanego paliwa na uzyskiwaną liczbę kropel w strudze oraz na uzyskiwaną wartość pola powierzchni kropel, które mają bezpośredni wpływ na efektywność procesu spalania. Przedstawiono jak zmienia się wielkość emisji toksycznych składników spalin ze wzrostem tzw. Średniej średnicy Sautera (SMD) kropel paliwa. Prezentowane rysunki pokazały, że wzrost średniej średnicy kropel SMD w zasadzie wywołuje wzrost emisji toksycznych składników spalin, tj. głównie tlenków azotu NO, tlenku węgla CO, węglowodorów HC oraz cząstek stałych (sadzy). Ten trend nie jest jednak stały, gdyż ulega ona zmianom wraz ze zmianami wartości współczynnika równoważności Φ. Na przykład emisja tlenków azotu dla mieszanek ubogich (Φ<1), wraz ze wzrostem średnich średnic kropel wzrasta, zaś już dla mieszanek bogatych (Φ>1) ta tendencja ulega istotnej zmianie, tzn. poziom tej emisji maleje.

EN

The paper contains analysis of the impact on the quality of the fuel spray of droplets on the number and the value of the surface area of the droplets that have a direct impact on the efficiency of the combustion process. It presents a change in the level of toxic exhaust emissions with an increase in the so-called. Sauter Mean Diameter (SMD) of fuel droplets. The presented figures show that the increase in the average droplet diameter SMD in particular causes an increase of toxic exhaust gases emissions, i.e. mainly nitrogen oxides NO, carbon monoxide CO, hydrocarbons HC and Particulate Matter (PM). This tendency is not constant, because it is changing according to changes of the coefficient of equivalence Φ. For example, emissions of nitrogen oxides for the lean mixtures (Φ <1), with an increase in average droplet diameter increases, while now for the rich mixtures (Φ> 1), this trend is significantly changed, i.e. the level of this emission decreases.

11

Dilatometric researches of novel alloy for combustion engine pistons

51%

Żurek J. , Slawinski Z. , Jankowski A.

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tom Vol. 23, No. 3

585--596

EN

The article presents dilatometric research results of composite alloy (in-situ) for combustion engines piston. Researches were performed with a precise dilatometer. Alloy's research test stand and test results including relative elongation, course of derivative of dimension increasing versus time with phase transition and course of coefficient of linear thermal expansion α for composite alloy versus temperature are presented in the article. Novel composite alloy allows getting a minimum difference of the coefficient of linear thermal expansion α during heating and cooling. In particular, the chemical composition of the novel composite silumin alloys; ATD of standard alloy – silumin Ak12 and novel composite alloy; schema of research stand and view of the measuring-head of the extension; course of the coefficient of linear thermal expansion α versus temperature during heating and cooling for the standard alloy and novel composite alloy; course of the relative piston elongation ΔL/Lo versus temperature during heating and cooling for the standard alloy and novel composite alloy; course of the derived function of the extension in relation to time dL/dt versus temperature for the standard alloy on pistons and novel composite alloy; course of the relative elongation in function of time during ageing of composite alloy at the temperature of 200°C with two-stage ageing process; course of the relative elongation in function of time during ageing of composite alloy at the temperature of 200°C for the first stage and second stage are presented in the article.

12

Transfer protonów w biopolimerach

51%

Jankowski A. , Dobryszycki P. , Stefanowicz P.

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tom 16

13

Professor Zbigniew Smalko for the 21st century science of reliability, safety and transport (birthday festschrift)

51%

Jankowski A. , Jaźwiński J. , Salamonowicz T.

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tom Vol. 13, No. 2

9-31

EN

Prof. Zbigniew Smalko is a creator of the Polish school of reliability, also in the literal sense, because he organized 34 Winter Schools of Reliability under the auspices of Polish Academy Sciences. The Schools were devoted to different problems. Schools Reliabilities concerning machines and vehicles concentrate outstanding scientists and in this domain the Polish science places itself in the world first ranks. In the last period Prof. Smalko actively attends in the International Scientific Congresses of European KONES. Prof. Z. Smalko, outstanding scientist has about 200 papers and the monograph. In many scientific domains he is a pioneer and leader. Prof. Smalko concentrated round himself the society of outstanding co-workers, who along with him, but also independently, continue his work and then independently develop it. Prof. Smalko is a member of a lot of domestic and world Scientific Associations and Societies, in this elitist ones such as European KONES, where he acts functions from the elections. Beside the scientific activity expressed in his novel papers, Prof. Smalko actively participates in domestic and international symposia, conferences and Congresses not only as an author and chairman, but also as a very careful listener and discussion participant, as well as an attraction explorer of the culture and art of remote countries. Prof. Smalko has a great scientific authority, he is a member of many organizations and Scientific Societies domestic and foreign. Superlative is an election of Prof. Smalko to the State Committee for Scientific Research as a Member (2 times). The scientific activity of Prof. Smalko mainly concentrates in Polish Academy of Sciences, Faculty of Transport of the Warsaw University of Technology, and the Air Force Institute of Technology.

14

Rola kompleksu IL-6-sIL-6R oraz jego naturalnego inhibitora sgp130 w modulowaniu procesu zapalnego

51%

Augustyniak D. , Majkowska-Skrobek G. , Basiewicz-Worsztynowicz B. , Jankowski A.

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nr 2

194-203

15

Investigation of the fuel spray atomization spectrum in common-rail system for diesel engines

51%

Jankowski A. , Siemińska-Jankowska B. , Sandel A. , Bocheński C.

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tom Vol. 10, No. 1-2

53-64

EN

Experimental results of the influence of the fuel viscosity and injection pressure on the fuel droplet diameter and velocity distribution in a fuel spray are presented in this paper. The experiments were carried out on the special test stand with the constant volume chamber. The measurements were performed using the LDV, PDPA, and P/y laser systems. Two experimental Diesel fuels for compression ignition engines with different viscosity values were used in the experiments. The injection pressures varied from 50 MPa to 130 MPa. The tests results show that the common rail injection systems, when it was fuelled with the fuel of smaller viscosity produce the droplets of smaller diameters than fuel with a bigger viscosity value. As the injection pressure was increased the droplets with finer diameter as well as for fuel with smaller and with bigger viscosity has been produced by this system. In this paper samples of the experimental results of the velocity fields in the fuel sprays are also presented.

16

Some problems of improvement of fuel efficiency and emissions in internal combustion engines

51%

Jankowski A. , Sandel A. , Sęczyk J. , Siemińska-Jankowska B.

Journal of KONES

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2002

|

tom Vol. 9, No. 1-2

333-356

EN

Analysis of some design for both compression ignition and spark ignition engines which give improvement from point of view fuel efficiency and pollutant emission including CO2 are presented in the paper. Actual and future standards requirement for pollutant emissions and CO2 as well test procedures, generally for light duty car for Californian standards and European standards are overviedwed. Especially common rail system for compression ignition and spark ignition engines were presented. Air assist system which can be applied for four stroke and two stroke engines was described too. Gasoline direct injection system which operate in 2 modes: lean burn mixture when engine run with a part load and homogeneous charge with stoichiometric mixture when engine run with high load is presented. Lean stratified mixture is realized as a late fuel injection during compression stroke but homogenous charge is realized as a early fuel injection during induction stroke. Lean mixtures require to apply special de - NOx catalytyst which joined with three way catalytyst (TWC) enable meet of standard requirements concerning exhaust emission. Investigation concerning some solutions of mixture preparation process and combustion were conducted. Mixture preparation process investigations were conducted with laser Doppler equipment LDV (3D) and PDPA. Combustion processes ware conducted in constant volume chamber. During combustion process testing the flow field, fuel droplet dimension and structure of fuel spray profitable for ignition process close to spark plug was determined. If velocity of the droplet in spark plug was near zero and droplet dimension were small repeatable ignition for lean mixture was obtained.

17

Analysis of fuel spray preparation for internal combustion engines

51%

Jankowski A. , Sandel A. , Sęczyk J. , Siemińska-Jankowska B.

Journal of KONES

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2002

|

tom Vol. 9, No. 1-2

323-332

EN

In this paper the results of the drop size and its distribution in fuel spray produced by common rail and air assist systems of injection have been presented. Measuring equipment and testing have been described. The laser systems: LDV, PDPA and RSA have been applied to perform of the measurements. The results show that by applying the common rail system and air assist system can be obtain similar size dimension of droplet in injected fuel spray. Introduction of very high pressure direct injection in CI engines, GDI and air - assist systems in SI engines were beneficial from the view point of emission and fuel consumption.

18

Badania widma rozpylenia paliwa w systemie common – rail do silników z zapłonem samoczynnym

51%

Bocheński C. , Jankowski A. , Sandel A. , Siemińska-Jankowska B.

Journal of KONES

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2002

|

tom Vol. 9, No. 1-2

311--322

PL

W artykule przedstawiono wyniki badań wpływu lepkości paliwa i ciśnienia wtrysku na wymiary średnic kropel paliwa i rozkłady prędkości kropel w strudze. Badania przeprowadzono na specjalnym stanowisku badawczym z komorą o stałej objętości. Pomiary prowadzono przy zastosowaniu laserowych systemów LDV, PDPA, PIV. W badaniach stosowano dwa paliwa badawcze różniące się lepkością. Stosowano ciśnienie wtrysku od 50 MPa do 130 MPa. Wyniki badań wskazują, że przy zasilaniu paliwem o mniejszej lepkości badany układ common rail generował krople o mniejszej średnicy zarówno w odniesieniu do paliwa o mniejszej lepkości, jak i do paliwa o większej lepkości. W artykule zamieszczono także przykładowe wyniki badań pola prędkości w strudze wtryskiwanego paliwa.

EN

Experimental results of the influence of the fuel viscosity and injection pressure on the fuel droplet dimension and velocity distribution in a fuel spray are presented in this paper. The experiments were carried out on the special test stand with the constant volume chamber. The measurements were performed using the LDV, PDPA, PIV laser systems. Two experimental fuels for compression ignition engines with different viscosity values were used in the experiments. The injection pressures were varied from 50 MPa to 130 MPa. The tests results show that the common rail injection systems, when it was fuelled with the fuel of smaller viscosity produce the droplets of smaller dimensions than fuel with a bigger viscosity value. As the injection pressure was increased the droplets with finer dimension as well as for fuel with smaller and with bigger viscosity has been produced by this system. In this paper samples of the experimental results of the velocity fields in the fuel sprays are presented, too.

19

A randomised, double-blind study on the efficacy of Tolpa Torf Preparation [TTP] in the treatment of recurrent respiratory tract infections

51%

Jankowski A. , Nienartowicz B. , Polanska B. , Lewandowicz-Uszynska A.

|

nr 1

20

The new SIMD Implementation of the Smith-Waterman Algorithm on Cell Microprocessor

45%

Rudnicki W. R. , Jankowski A. , Modzelewski A. , Piotrowski A. , Zadrożny A.

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tom Vol. 96, nr 1/2

181-194

EN

Algorithms for estimating similarity between two macromolecular sequences are of profound importance for molecular biology. The standard methods utilize so-called primary structure, that is a string of characters denoting the sequence of monomers in hetero-polymer. These methods find the substrings of maximal similarity, as defined by the so-called similarity matrix, for a pair of two molecules. The problem is solved either by the exact dynamic programming method, or by approximate heuristic methods. The approximate algorithms are almost two orders of magnitude faster in comparison with the standard version of the exact Smith-Waterman algorithm, when executed on the same hardware, hence the exact algorithm is relatively rarely used. Recently a very efficient implementation of Smith-Waterman algorithm utilizing SIMD extensions to the standard instruction set reduced the speed advantage of heuristic algorithms to factor of three. Here we present an improved implementation of the Smith-Waterman algorithm on the Cell processor. Implementation presented here achieves execution speed of approximately 9 GCUPS. The performance is independent on the scoring system. It is 4 to 10 times faster than best Smith-Waterman implementation running on a PC and 1.5 to 3 times faster than the same implementation running on Sony PlayStation 3. It is also 5 times faster than the recent implementation of the Smith-Waterman utilizing Nvidia GPU. Our implementation running on Sony PlayStation 3 has performance which is directly comparable with that of BLAST running on PC, being up to 4 times faster in the best case and no more than two times slower in the worst case. This performance level opens possibility for using the exact Smith-Waterman algorithm in applications, where currently approximate algorithms are used.