Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "unsteady" wg kryterium: Temat


Tytuł:
Improved method for simulating frictional losses in laminar transient liquid pipe flow
Autorzy:
Urbanowicz, K.
Zarzycki, Z.
Kudźma, S.
Powiązania:
https://bibliotekanauki.pl/articles/1943217.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska
Tematy:
unsteady pipe flow
unsteady friction
weighting function
Opis:
This paper is devoted to the problem of energy dissipation and it concerns unsteady friction modeling of the liquid flow in hydraulic lines. One dimensional (1D) quasi-steady model of energy dissipation is in common use. It means that the loss of energy is estimated by the Darcy-Weisbach formulae. Such an approximation is close to reality only for slow changes of the velocity field in the pipe cross-section. In case of fast changes, like fast transients, e.g. water hammer, it fails. In this work the wall shear stress (defined as an effect of unsteady fluid friction) is presented as a sum of quasi-steady and unsteady components. The unsteady component of the wall shear stress is modeled as an convolution of the local fluid acceleration and a weighting function w(t). The weighting function, in general, makes an allowance for a relation of the historic velocity changes and the unsteady component of the wall shear stress. Primitive weighting functions have usually very complicated structures, and what is more, they make it impossible to perform an efficient simulation of dynamical runs. In this paper, a new weighting function is presented as a sum of exponential components in order to enable efficient calculation of the unsteady component wall shear stress. A few examples of the new effective method of unsteady wall shear stress simulations, in case of the water hammer, are presented. The results of the calculations are compared with experiments known in literature and satisfying results are obtained.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2010, 14, 3; 175-188
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of different one-stage blower designs using three-dimensional unsteady numerical flow simulation
Autorzy:
Kalmar, L.
Janiga, G.
Fodor, B.
Soltesz, L.
Powiązania:
https://bibliotekanauki.pl/articles/175582.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
blower
numerical simulation
unsteady flow
Opis:
This paper deals with the computational fluid dynamics investigation of the flow in a one-stage radial flow blower-aggregate. The main aim of this numerical study is to compute the relevant operating characteristics of the blower and to determine detailed information about the flow characteristics inside it. The distributions of these flow characteristics in the blower determined by the commercial code are available to judge whether the elements of the blower are working properly, or not. The calculated characteristics of operating parameters are compared with measured data given by experimental tests of the blower-aggregate for their validation.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2014, 126; 55-64
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of steam extraction parameters on unsteady rotor forces
Autorzy:
Rządkowski, R.
Gnesin, V.
Powiązania:
https://bibliotekanauki.pl/articles/1933176.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska
Tematy:
steam extraction
blade
unsteady forces
Opis:
Aerodynamic unsteady forces of rotor blades in a turbine stage with steam extraction were calculated and blade failure was reported. A numerical calculation of the 3D transonic flow of an ideal gas through turbomachinery blade rows moving one in relation to another is presented. An ideal gas flow through mutually moving stator and rotor blades with periodicity on the whole annulus is described with unsteady Euler conservation equations, integrated using the explicit monotonous finite-volume difference scheme of Godunov-Kolgan and a moving hybrid H-H grid. In order to find the pressure distribution of steam parameters behind the rotor blades, calculations were performed for a steady flow through the stage and the steam extraction channels using the SPARC program and the unsteady forces of the rotor blade were calculated for four steam extraction conditions. For the maximal steam extraction the 10th harmonic of the axial force and moment was found to be close to the first natural frequency of the bladed disc with one nodal diameter. Thus, steam extraction can be the cause of the blade's failure.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2007, 11, 3; 253-261
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Modeling of unsteady turbulent flows in turbomachines
Autorzy:
Magagnato, F.
Powiązania:
https://bibliotekanauki.pl/articles/1967650.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
turbulence
compressible
unsteady
RANS
LES
Opis:
The suitability of existing models for the simulation of flow through turbomachines is investigated and compared with a recently proposed adaptive turbulence model. Discussed are the improvements in accuracy that can be achieved by using non-linear turbulence models and unsteady calculations. The adaptive turbulence model is based on two equation turbulence modeling. It uses the temporal and spatial scales of the flow field to automatically adapt itself to the unresolved turbulent fluctuations. At its asymptotic limits it reduces either to a Direct Numerical Simulation – when the turbulent scales are in the order of the Kolmogorov micro scale – or to a standard two equation model – when the fluctuations are not resolved at all. In order to compare the quality of the presented models two cases have been considered: the flow past a cylinder and a subsonic as well as transonic flow past the VKI turbine blade. Calculations have been performed for each case using all the models and the results have been compared with measurements. The unsteady calculations gave better agreement with the experimental data demonstrating the superiority over steady state calculations for turbomachines.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 477-494
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady performance of an HP turbine stage optimised for steady flow conditions
Autorzy:
Świrdyczuk, J.
Powiązania:
https://bibliotekanauki.pl/articles/1964172.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska
Tematy:
turbine stage
blade optimisation
unsteady effects
Opis:
The article is focused on the examination of the unsteady performance of an HP turbine stage the blades of which were previously optimised for steady flow conditions. For the purpose of this examination, two pairs of initial and optimised stages of comparable output parameters were selected. The results have revealed that the modification of the blade profile in the optimisation process made the rotor blades more vulnerable to unsteady flow fluctuations, which eventually cancelled a considerable part of the stage efficiency gained from the steady flow optimisation.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2005, 9, 2; 187-198
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady Shock Wave: Turbulent boundary layer interaction in the Laval Nozzle
Autorzy:
Doerffer, P.
Szulc, O.
Magagnato, F.
Powiązania:
https://bibliotekanauki.pl/articles/1965143.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska
Tematy:
unsteady transonic flow
shock waves
nozzle flow
Opis:
The flow in transonic diffusers and supersonic air intakes often becomes unsteady due to shock wave-boundary layer interaction. Oscillations may be induced by natural separation unsteadiness or forced by boundary conditions. Significant improvements of CFD tools, increased computer resources and the development of experimental methods have again drawn the attention of researchers to this topic. Forced oscillations of a transonic turbulent flow in an asymmetric two-dimensional Laval nozzle have been considered to investigate the problem. A viscous, perfect gas flow was numerically simulated using SPARC, a Reynolds-averaged compressible Navier-Stokes solver, employing a two-equation, eddy viscosity, turbulence closure in the URANS approach. For time-dependent and stationary flow simulations, Mach numbers upstream of the shock between 1.2 and 1.4 were considered. Comparison of computed and experimental data for steady states generally gave acceptable agreement. In the case of forced oscillations, a harmonic pressure variation was prescribed at the exit plane resulting in shock wave motion. Excitation frequencies between 0Hz and 1024Hz were investigated at a constant pressure amplitude. The main result of the work is the relation between the amplitude of shock wave motion and the excitation frequency in the investigated range. Increasing excitation frequency resulted in decreasing amplitude of the shock movement. At high frequencies, a natural mode of shock oscillation (of small amplitude) was observed, which was insensitive to forced excitement.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2005, 9, 1; 115-132
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of unsteady forces acting on a slender cylinder
Autorzy:
Ziółkowski, P. J.
Witkowski, W.
Sobczyk, B.
Powiązania:
https://bibliotekanauki.pl/articles/175172.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
unsteady flow
FSI
CFD modelling
CSD modelling
Opis:
Developments in construction engineering (new materials, construction techniques) facilitate the design of very flexible, light structures with low damping which unfortunately results in higher susceptibility of these structures to wind action. It is therefore necessary to use more accurate scientific tools in the engineering phase of these structures. Analytical methods for considering wind effects on structures encounter difficulties with respect to mathematical formulations of aerodynamic forces. In this paper a 2D numerical model has been described which considers the fluid domain with respect to a cylindrical obstacle. This 2D model has been discretized using the finite volume method, and numerical simulations have been undertaken in order to describe the unsteady flow conditions within the analyzed domain. The simulations have been performed with boundary conditions characterizing the flow past a cylindrical obstacle. The results have been compared with the literature data from similar experiments. On the basis of the flow characteristics obtained, as well as the spatial distributions of the flow parameters, a model for further 3D analyses was selected. Next, a 3D numerical study of unsteady flow forces acting on a slender cylinder has been analyzed. Toward the end, a two-way fluid solid interaction approach has been utilized, which incorporates a computational fluid dynamics approach combined with computational solid dynamics.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2018, 140; 23-38
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of unsteady flow forces on the thermowell of steam temperature sensor
Autorzy:
Kornet, S.
Sławiński, D.
Ziółkowski, P.
Badur, J.
Powiązania:
https://bibliotekanauki.pl/articles/175578.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
unsteady flow
resonance
CFD modeling
CSD modeling
Opis:
In this paper, 3D numerical analysis of unsteady flow forces acting on the thermowell of steam temperature sensor is presented. According to that purpose, the CFD+CSD (computational fluid–solid dynamics) approach has been used. The nonstationary of fluid acting on the thermowell such as: Strouhal frequency, amplitude of pressure, structure of vortex, peak of pressure, field of pressure, field of velocity, etc. are studied analytically and numerically. There have been examined two cases of flow with changing both temperature, pressure and mass flow rate (operating daily and night in the unit with capacity of 380 MWe). In accordance with the standards ASME PTC 19.3 TW-2010 the possibility of entry into resonance has been examined.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2015, 129; 25-49
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved method for simulating transients of turbulent pipe flow
Autorzy:
Zarzycki, Z.
Kudźma, S.
Urbanowicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/280935.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
unsteady pipe flow
transients
waterhammer
efficient numerical simulation
Opis:
The paper presents the problem of modelling and simulation of transients during turbulent fluid flow in hydraulic pipes. The instantaneous wall shear stress on a pipe wall is presented in the form of integral convolution of a weighting function and local acceleration of the liquid. This weighting function depends on the dimensionless time and Reynolds number. Its original, very complicated mathematical structure is approximated to a simpler form which is useful for practical engineering calculations. The paper presents an efficient way to solve the integral convolution based on the method given by Trikha (1975) for laminar flow. An application of an improved method with the use of the Method of Characteristic for the case of unsteady flow (water hammer) is presented. This method is characterised by high efficiency compared to traditional numerical schemes.
Artykuł przedstawia zagadnienie modelowania i symulacji przebiegów przejściowych podczas turbulentnego przepływu cieczy w przewodach ciśnieniowych. Chwilowe naprężenie styczne na ściance przewodu przedstawiono w postaci całki splotowej z funkcji wagi i przyspieszenia cieczy. Funkcja wagi dla naprężenia stycznego na ściance przewodu zależy od czasu bezwymiarowego i liczby Reynoldsa. Ma ona zawiłą postać matematyczną, dlatego aproksymowano ją do prostszej postaci, przydatnej do praktycznych obliczeń inżynierskich. Przedstawiono efektywny sposób rozwiązania całki splotowej, opierając się na metodzie podanej przez Trikha (1975) dla przepływu laminarnego. Podano zastosowanie ulepszonej metody symulacji naprężenia stycznego do metody charakterystyk podczas uderzenia hydraulicznego. Charakteryzuje się ona dużą efektywnością w stosunku do metody tradycyjnej.
Źródło:
Journal of Theoretical and Applied Mechanics; 2011, 49, 1; 135-158
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of flight control law on spin dynamics of aerodynamically asymmetric aircraft
Autorzy:
Malik, B.
Akhtar, S.
Masood, J.
Powiązania:
https://bibliotekanauki.pl/articles/279175.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
aerodynamic model
steady spin modes
unsteady effects
simulations
Opis:
In this paper, we analyze the spin dynamics of an aerodynamically asymmetric aircraft in open-loop configuration and also evaluate the performance of gain scheduled flight control law in improving dynamic characteristics of aircraft spin. A look-up tables based aerodynamic model is developed from static, coning and oscillatory coning rotary balance wind tunnel test data. As a starting point, all possible steady spin modes are identified by solving the aircraft dynamic model comprising moment equations. The influence of high-alpha yawing moment asymmetry on predicted right and left spin modes is discussed. Six degree of freedom simulations of left and right flat spins are performed in open-loop and closed-loop configurations with the flight control law. Our studies reveal that large amplitude oscillations in the angle of attack and sideslip observed in the open-loop configuration are significantly damped by the control law. The control law reduces the recovery time of the left flat spin. However, the aircraft natural tendency to rotate rightwards due to yawing moment asymmetry at high angles of attack renders flight control law ineffective in aiding the recovery of the right flat spin.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 3; 963-975
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of compressor rotor blade clocking effects on aerodynamic loading of the stator vane
Analiza numeryczna wpływu wzajemnego ustawienia łopat sprężarki na obciążenie aerodynamiczne kierownicy
Autorzy:
Yan, P. G.
Qiang, X. Q.
Du, Z. H.
Han, W. J.
Powiązania:
https://bibliotekanauki.pl/articles/280439.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
compressor
unsteady low
clocking effect
flow exciting force
Opis:
The unsteady flow fields of a three-stage axial compressor are simulated. The 3D N-S equations are solved by using the frequency domain transformed method based on the harmonic function. The main efforts are focused on the effects of the second stage rotor blade clocking configuration on aerodynamic loading of the stator vanes. The unsteady aerodynamic loadings of each blade row are analyzed in time and frequency domains. The results point out that the aerodynamic loading of the middle stage stator vane is significantly affected as the rotor blades changing with different clocking configuration. At CLK0 configuration, the middle stage stator vane is affected by the aerodynamic force whose direction is sometimes reverse with the regular force. At CLK2 configuration, the aerodynamic force of the stator vane is always positive and the fluctuation amplitude is smaller than those of other configurations. Meanwhile, the response of stator vane S2 to one blade passing frequency (BPF) is minimum comparing to others.
Praca zawiera wyniki symulacji numerycznej nieustalonego pola przepływu w trójstopniowej sprężarce osiowej. Trójwymiarowe równania Naviera-Stokesa rozwiązano metodą transformacji w dziedzinie częstości opartej na funkcji harmonicznej. Główny wysiłek włożono w badania wpływu konfiguracji łopat kierownicy i wirnika drugiego stopnia sprężarki na obciążenie aerodynamiczne kierownicy. Obciążenie to o charakterze nieustalonym przeanalizowano dla każdego rzędu łopatek w dziedzinie czasu i częstości. Wyniki wykazały, że obciążenie aerodynamiczne kierownicy środkowego stopnia sprężarki znacząco zależy od wzajemnego ustawienia łopat wirnika i kierownicy. Dla konfiguracji oznaczonej CLK0 kierownica podlega obciążeniu siłą, której zwrot bywa przeciwny do kierunku typowego w przypadkach regularnych. Natomiast konfiguracją CLK2 generuje zawsze dodatnią wartość siły aerodynamicznej, której fluktuacje amplitudy są jednocześnie mniejsze niż w innych konfiguracjach. Ponadto stwierdzono, że wrażliwość aerodynamiczna łopaty kierownicy S2 na częstotliwość łopatkową (BPF) jest minimalna w stosunku do innych konfiguracji.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 2; 423-440
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Description of Long Water Waves in Material Variables
Autorzy:
Szmidt, K.
Hedzielski, B.
Powiązania:
https://bibliotekanauki.pl/articles/241085.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
long waves
shallow water
unsteady motion
sloping beach
Opis:
Shallow water equations formulated in material variables are presented in this paper. In the model considered, a three-dimensional physical problem is substituted by a two-dimensional one describing a transformation of long waves in water of variable depth. The latter is obtained by means of the assumption that a vertical column of water particles remains vertical during the entire motion of the fluid. Under the assumption of small, continuous variation of the water depth, the equations for gravity waves are derived through Hamilton's principle formulated in terms of the material coordinates. This formulation ensures the conservation of mechanical energy. The approximation depends on the wave parameters as well as on the bed bathymetry. The latter may influence a solution of the model decisively; thus, one should be careful in applying the description to complicated geometries of fluid domains encountered in engineering practice.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2009, 56, 1-2; 63-83
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and simulation of PE100 pipe response under transient events caused by pump failure
Autorzy:
Bettaieb, Noura
Chalghoum, Issa
Sami, Elaoud
Taieb, Ezzeddine Hadj
Powiązania:
https://bibliotekanauki.pl/articles/280849.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
water hammer
PE100
pump failure
viscoelasticity
unsteady friction
Opis:
In this work, the response of a PE100 pipe under transient events following pump failure is numerically investigated. The developed numerical model was based on the generalized Kelvin-Voigt model and the Vitkovsky et al. formulation. The method of characteristics (MOC) was used for numerical discretization. The relevance of an unsteady friction term in the pressure wave damping was analyzed. Pressure and circumferential stress responses indicated high rates in the pressure waves damping for the PE100 pipe. Through a parametric study, it was shown that the HDPE pipe may serve in damping and dispersing pressure waves without the need for additional protection devices.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 4; 1039-1054
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Velocity distribution in slide journal bearing gap by laminar unsteady lubrication
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/245516.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
laminar unsteady lubrication
journal slide bearing
pressure
velocity perturbation
Opis:
This paper shows results of numerical solutions the modified Reynolds equations for laminar unsteady oil flow in slide journal bearing gap. Laminar unsteady oil flow is performed during periodic and unperiodic perturbations of bearing load or is caused by the changes of gap height in time. Above perturbations occur mostly during the starting and stopping of machine. During modelling crossbar bearing operations in combustion engines, bearing movement perturbations from engine vertical vibrations causes velocity flow perturbations of lubricating oil on the bearing race and on the bearing slider in the circumferential direction. This solution example applies to isothermal bearing model with infinity length. Lubricating oil used in this model has Newtonian properties and constant dynamic viscosity. Perturbations connected with unsteady lubricating oil velocity in the circumferential direction on the slide bearing and on the slider of bearing were taken into consideration. Results are presented in the dimensionless hydrodynamic pressure and velocity distribution diagrams. Received solutions were compared with the solution received by the stationary lubrication flow in the slide journal bearing, which were made with the same parameter assumption by constant dynamic oil viscosity. Isothermal bearing model is similar to friction node model by steady-state heat load conditions.
Źródło:
Journal of KONES; 2011, 18, 3; 177-184
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Drag force on a flat plate in cavitating flows
Autorzy:
Seif, M. S.
Asnaghi, A.
Jahanbakhsh, E.
Powiązania:
https://bibliotekanauki.pl/articles/258824.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
numerical simulation
cavitation
psio algorithm
flat plate
unsteady flow
Opis:
The present study focuses on the simulation of two dimensional unsteady cavitating flows. For simulation of unsteady behaviors of cavitation which have practical applications, the development of unsteady PISO algorithm based on the non-conservative approach is utilized. For multi-phase simulation, single-fluid Navier–Stokes equations, along with the volume fraction transport equation, are employed. The bubble dynamics model is utilized to simulate phase change between vapor and liquid phases of the water. Unsteady simulation of cavitation around NACA66(MOD) and supercavitation around a flat plate normal to flow direction are performed to clarify accuracy of presented model. Numerical results and comparisons with experimental data are provided. The accuracy is good, and it is possible to apply this method to more complex shapes.
Źródło:
Polish Maritime Research; 2009, 3; 18-25
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies