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Wyświetlanie 1-15 z 61
Tytuł:
A Mathematical Model of Membrane Gas Separation with Energy Transfer by Molecules of Gas Flowing in a Channel to Molecules Penetrating this Channel from the Adjacent Channel
Autorzy:
Szwast, M.
Szwast, Z.
Powiązania:
https://bibliotekanauki.pl/articles/185043.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
membrane
membrane module
reciprocal transfer of energy between gas molecules
changes of the pressure of gas along the length of flow channel
membrana
wzajemne przekazywanie energii między cząsteczkami gazu
zmiany ciśnienia gazu na długości kanału przepływowego
Opis:
The paper presents the mathematical modelling of selected isothermal separation processes of gaseous mixtures, taking place in plants using membranes, in particular nonporous polymer membranes. The modelling concerns membrane modules consisting of two channels – the feeding and the permeate channels. Different shapes of the channels cross-section were taken into account. Consideration was given to co-current and counter-current flows, for feeding and permeate streams, respectively, flowing together with the inert gas receiving permeate. In the proposed mathematical model it was considered that pressure of gas changes along the length of flow channels was the result of both – the drop of pressure connected with flow resistance, and energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel. The literature on membrane technology takes into account only the drop of pressure connected with flow resistance. Consideration given to energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel constitute the essential novelty in the current study. The paper also presents results of calculationsobtained by means of a computer program which used equations of the derived model. Physicochemical data concerning separation of the CO2/CH4 mixture with He as the sweep gas and data concerning properties of the membrane made of PDMS were assumed for calculations.
Źródło:
Chemical and Process Engineering; 2015, 36, 2; 151-169
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new approach for study the electrohydrodynamic oscillatory flow through a porous medium in a heating compliant channel
Autorzy:
Haroun, M. H.
Powiązania:
https://bibliotekanauki.pl/articles/1839817.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przepływ oscylacyjny
elektrohydrodynamika
wymiana ciepła
oscillatory flow
electrohydrodynamics
porous medium
heat transfer
compliant channel
Opis:
The governing equations of an electrohydrodynamic oscillatory flow were simplified, using appropriate nondimensional quantities and the conversion relationships between fixed and moving frame coordinates. The obtained system of equations is solved analytically by using the regular perturbation method with a small wave number. In this study, modified non-dimensional quantities were used that made fluid pressure in the resulting equations dependent on both axial and vertical coordinates. The current study is more realistic and general than the previous studies in which the fluid pressure is considered functional only in the axial coordinate. A new approach enabled the author to find an analytical form of fluid pressure while previous studies have not been able to find it but have found only the pressure gradient. Analytical expressions for the stream function, electrical potential function and temperature distribution are obtained. The results show that the electrical potential function decreases by the increase of the Prandtl number, secondary wave amplitude ratio and width of the channel.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 3; 30-44
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Through Capacity Model for One-way Channel Based on Characteristics of the Vessel Traffic Flow
Autorzy:
Nie, Y.
Liu, K.
Xin, X.
Yu, Q.
Powiązania:
https://bibliotekanauki.pl/articles/115997.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
maritime traffic
vessel traffic service (VTS)
vessel traffic flow
one-way channel
mathematical model
Automatic Identification System (AIS)
Opis:
Vessel traffic flow is a key parameter for channel-through capacity and is of great significance to vessel traffic management, channel and port design and navigational risk evaluation. Based on the study of parameters of characteristics of vessel traffic flow related to channel-through capacity, this paper puts forward a brand-new mathematical model for one-way channel-through capacity in which parameters of channel length, vessel arrival rate and velocity difference in different vessels are involved and a theoretical calculating mechanism for the channel-through capacity is provided. In order to verify availability and reliability of the model, extensive simulation studies have been carried out and based on the historical AIS data, an analytical case study on the Xiazhimen Channel validating the proposed model is presented. Both simulation studies and the case study show that the proposed model is valid and all relative parameters can be readjusted and optimized to further improve the channel-through capacity. Thus, all studies demonstrate that the model is valuable for channel design and vessel management.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2017, 11, 3; 495-502
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A turbulence model for 3-d flows with anisotropic structure of turbulence
Autorzy:
Czernuszenko, W.
Rylov, A.
Powiązania:
https://bibliotekanauki.pl/articles/241364.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
3D flow
mathematical model
numerical simulation
open channel flow
turbulence model
Opis:
A new turbulence model for flows in open channels with compound cross-sections is presented. The structure of turbulence in these channels can be anisotropic. This structure is described by the turbulent stress tensor that is presented here as the sum of two tensors, namely, normal and shear stress tensors. The normal and shear turbulent stresses are expressed by the turbulence intensities and the mixing length tensor (MLT), respectively. The turbulence intensities can be learned from measurements or another suitable approaches. One such approach that allows calculating the main component of the normal stresses is presented in the paper. The components of MLT are defined based on a new concept of generic mixing length (GML). The generic mixing length is assumed to depend on both distances; from the nearest wall and from the water surface. To demonstrate how the new model works the basic hydrodynamic equations (parabolic approximation of Reynolds equations) together with the turbulence model are solved. The well-known Patankar and Spalding (1972) algorithm was used when solving these equations. A series of numerical simulations were performed for different components of MLT and different channel geometries.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2005, 52, 4; 303-320
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza systemu informacji logistycznej na przykładzie wybranego centrum dystrybucji
Logistics information system analysis in distribution center
Autorzy:
Grabowska, J.
Powiązania:
https://bibliotekanauki.pl/articles/321494.pdf
Data publikacji:
2014
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
system informacji logistycznej
centrum dystrybucji
kanał dystrybucji
przepływ informacji
system informatyczny
logistic information system
distribution center
distribution channel
information flow
information system
Opis:
Celem niniejszego artykułu jest przedstawienie systemu informacji logistycznej uczestników kanału dystrybucji artykułów sportowych oraz analiza przepływu informacji w wybranym centrum dystrybucji. Określono także przyczyny powstania zakłóceń w realizacji procesu zamówienia.
The purpose of this article is to analyze the logistics information system of participants in sporting articles distribution channel and analysis of the flow of information in the selected distribution center. This article defines the concept of logistics information and logistics information system. Shows the causes of interference in the implementation of the order process.
Źródło:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska; 2014, 70; 163-175
1641-3466
Pojawia się w:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of controlled molecular dynamic flow in a channel with non-equal inlet and outlet cross-sectional areas
Autorzy:
Najafi, H. R.
Karimian, S. M. H.
Powiązania:
https://bibliotekanauki.pl/articles/279977.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
molecular dynamics
nano-channel
steady flow
non-equal inlet and outlet
pressure
Opis:
Thermo-fluid properties are required for numerical modeling of nano/micro devices. These properties are mostly obtained from the results of molecular dynamics (MD) simulations. Therefore, efforts have been made to develop methods for numerical evaluation of fluid properties such as pressure and velocity. One of the main challenges faced by numerical simulations is to simulate steady molecular flow in channels with non-equal inlet and outlet boundaries. Currently, periodic boundary conditions at the inlet and outlet boundaries are an inevitable condition in many steady flow molecular dynamics simulations. As a result, a nano-channel with different cross sectional areas at the inlet and outlet could not be simulated easily. Here, a method is presented to generate and control steady molecular flow in a nano-channel with different cross sectional areas at the inlet and outlet. The presented method has been applied to a converging-diverging channel, and its performance has been studied through qualitative and quantitative representation of flow properties.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1141-1153
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Effect of Channel Parameters between Filaments and Single Fabric Parameters on Air Permeability, Water Vapour Resistance and Thermal Resistance
Analiza wpływu wielkości parametrów kanału międzynitkowego i parametrów tkaniny pojedynczej na przepuszczalność powietrza, opór pary wodnej oraz opór cieplny
Autorzy:
Polipowski, M.
Więcek, P.
Więcek, B.
Pinar, A.
Powiązania:
https://bibliotekanauki.pl/articles/231662.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
air permeability
water vapor flow
thermal resistance
ANOVA
inter-yarn channel parameters
przepuszczalność powietrza
przepływ pary wodnej
opór cieplny
parametry kanału międzynitkowego
Opis:
The work presented is a continuation of research on the interthread channels of single fabric taking into account the parameters of fabric structure. The stereographic method of threedimensional structure analysis of a single fabric, the method of 3D microscopy of fabric fragments in structural light and analysis of microscopic images of the 4th generation were introduced. Statistical analysis of the air permeability, water vapour resistance and thermal resistance indicators for flat textile products showed significant dependences of these flow rates on channel parameters as well as other fabric parameters. The correlation between the parameters measured and the flow indicators was determined. Very strong correlations of the air permeability indicator were found with the channel clearance area, warp count and approximate channel volume. A strong correlation with the thickness of fabrics was obtained for the water vapour resistance indicator. For heat resistance there was a strong correlation with the diameter of channel inlets. Strong correlations between fabric parameters and channel parameters were obtained for the channel clearance area and approximate channel volume, warp and channel ground area, weft count and fabric thickness, channel inlet diameter, and fabric thickness.
Zaprezentowane prace są kontynuacją badań nad kanałami międzynitkowymi tkaniny pojedynczej z uwzględnieniem parametrów struktury tkaniny. Do identyfikacji kanałów międzynitkowych wprowadzono stereowizyjną metodę trójwymiarowej analizy struktury tkaniny pojedynczej, metodą mikroskanowania 3D fragmentów tkaniny w świetle strukturalnym oraz analizę obrazów mikroskopowych IV-ej generacji. Analiza statystyczna wskaźników przepuszczalności powietrza, oporu pary wodnej i oporu cieplnego płaskich wyrobów włókienniczych wykazała istotne zależności tych przepływów od parametrów kanału a także innych parametrów tkaniny. Określono korelacje między badanymi parametrami i wskaźnikami przepływowymi. Wykazano bardzo silne korelacje wskaźnika przepuszczalności powietrza z: polem prześwitu kanału, licznością osnowy i objętością przybliżoną kanału. Dla wskaźnika oporu pary wodnej uzyskano silną korelację z grubością tkaniny. Dla oporu cieplnego stwierdzono silną korelację ze średnicą wejścia do kanału międzynitkowego. Silne korelacje między parametrami tkaniny i parametrami kanału międzynitkowego uzyskano dla: pola powierzchni prześwitu kanału i objętości przybliżonej kanału, liczności osnowy i pola powierzchni prześwitu kanału, liczności wątku i grubości tkaniny, średnicy wejścia do kanału i grubości tkaniny. Badane wskaźniki przepływowe we wzajemnych zależnościach wykazały średni poziom korelacji. Eksperymentalne testy przepuszczalności powietrza, oporu pary wodnej oraz oporu cieplnego dla tkanin pojedynczych uzupełniły wiedzę o strukturze wyrobu i istotnego wpływu udziału surowca.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 5 (125); 79-86
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the influence of the heat-absorbing surface of an air-cooled solar collector on its thermal and mechanical properties
Autorzy:
Zhelykh, Vasyl
Ulewicz, Małgorzata
Kozak, Krystyna
Savchenko, Olena
Kasynets, Mariana
Powiązania:
https://bibliotekanauki.pl/articles/88616.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
solar air collector
heat-absorbing plate
flow turbulators
thermal power
air channel
powietrzny kolektor słoneczny
płyta pochłaniająca ciepło
turbulatory przepływowe
energetyka cieplna
kanał powietrzny
Opis:
This paper presents the analysis of existing forms of heat absorbing surfaces of air solar collectors, which gained the greatest popularity in the world. The obtained data allowed to conclude that there is a need for the development of solar collectors with air as a coolant with an improved form of heat absorber, which will reduce the operational and capital costs of solar systems and allow the efficient use of such structures in a moderate climate without additional mechanisms for the transfer of coolant. The use of computer simulation helped to compare the thermal characteristics of air-borne solar collectors of a different design. The substantiation of the expediency of installing as a heat absorber of flow turbulators in the form of a screw has been fulfilled, as well as the height of the air channel of the solar collector has been determined, in which the maximum heating of the transfer medium is observed. In addition, the loss of pressure in the air channel of the solar collector with flow turbulators was determined and the comparison of the obtained data with the values of pressure losses in the air collector of the matrix type and the air collector with V-shaped ribs was made.
Źródło:
System Safety : Human - Technical Facility - Environment; 2019, 1, 1; 481-489
2657-5450
Pojawia się w:
System Safety : Human - Technical Facility - Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical solutions of heat transfer for laminar flow in rectangular channels
Autorzy:
Rybiński, W.
Mikielewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/240574.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analytical solution
heat transfer
rectangular channel
laminar flow
fully developed
rozwiązanie analityczne
wymiana ciepła
kanał prostokątny
przepływ laminarny
Opis:
The paper presents two analytical solutions namely for Fanning friction factor and for Nusselt number of fully developed laminar fluid flow in straight mini channels with rectangular cross-section. This type of channels is common in mini- and microchannel heat exchangers. Analytical formulae, both for velocity and temperature profiles, were obtained in the explicit form of two terms. The first term is an asymptotic solution of laminar flow between parallel plates. The second one is a rapidly convergent series. This series becomes zero as the cross-section aspect ratio goes to infinity. This clear mathematical form is also inherited by the formulae for friction factor and Nusselt number. As the boundary conditions for velocity and temperature profiles no-slip and peripherally constant temperature with axially constant heat flux were assumed (H1 type). The velocity profile is assumed to be independent of the temperature profile. The assumption of constant temperature at the channel’s perimeter is related to the asymptotic case of channel’s wall thermal resistance: infinite in the axial direction and zero in the peripheral one. It represents typical conditions in a minichannel heat exchanger made of metal.
Źródło:
Archives of Thermodynamics; 2014, 35, 4; 29-42
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of variation of the parameters method for micropolar flow in a porous channel
Autorzy:
Güngör, Osman
Arslantürk, Cihat
Powiązania:
https://bibliotekanauki.pl/articles/1839802.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
micropolar flow
porous channel
variation of parameters method
przepływ mikropolarny
metoda zmiany parametrów
kanał porowaty
Opis:
This work devoted to study the injective micropolar flow in a porous channel. The flow is driven by suction or injection on the channel walls, and the micropolar model is used to characterize the working fluid. The governing nonlinear partial differential equations are reduced to the nonlinear ordinary coupled differential equations by using Berman’s similarity transformation. These equations are solved for large mass transfer via variation of parameters method (VPM) which has been used effectively in the solution of nonlinear equations recently. This method has not previously been applied to a problem of micropolar flow. The results of the variation of parameters method are found to be in excellent agreement with the results of the Matlab bvp4c solver (NUM). With this validity, the effects of the some important parameters on the velocity and rotation profile of micropolar flow are discussed in detail. It can be seen that increases in the values N1 and N3 have different results in comparison with N2 increasing.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 1; 17-29
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of variation of the parameters method for micropolar flow in a porous channel
Autorzy:
Güngör, Osman
Arslantürk, Cihat
Powiązania:
https://bibliotekanauki.pl/articles/122970.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
micropolar flow
porous channel
variation of parameters method
przepływ mikropolarny
metoda zmiany parametrów
kanał porowaty
Opis:
This work devoted to study the injective micropolar flow in a porous channel. The flow is driven by suction or injection on the channel walls, and the micropolar model is used to characterize the working fluid. The governing nonlinear partial differential equations are reduced to the nonlinear ordinary coupled differential equations by using Berman’s similarity transformation. These equations are solved for large mass transfer via variation of parameters method (VPM) which has been used effectively in the solution of nonlinear equations recently. This method has not previously been applied to a problem of micropolar flow. The results of the variation of parameters method are found to be in excellent agreement with the results of the Matlab bvp4c solver (NUM). With this validity, the effects of the some important parameters on the velocity and rotation profile of micropolar flow are discussed in detail. It can be seen that increases in the values N1 and N3 have different results in comparison with N2 increasing.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 1; 17-29
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cash flow sensitivity of investment: Evidence from the Polish listed companies
Autorzy:
Nehrebecki, Marian
Powiązania:
https://bibliotekanauki.pl/articles/1356332.pdf
Data publikacji:
2020-10-28
Wydawca:
Uniwersytet Warszawski. Wydział Nauk Ekonomicznych
Tematy:
investment
cash flow
ICFS
balance sheet channel
financial accelerator
Opis:
The paper focuses on assessment of the sensitivity of investment on cash flow (ICFS) made by listed companies in Poland. Achieving this goal will also involve analysing and drawing conclusions about the balance-sheet channel of monetary transmission. An empirical part uses data from financial statements for Poland derived from Emerging Markets Information Services (EMIS), related to companies listed on the Warsaw Stock Exchange and NewConnect. Estimations were made using the Ordinary Least Squares method with robust standard errors, and results made it clear that cash flow has a positive significant impact, indicating that most companies operate on the imperfect and incomplete market, and with constrained or costly access to external financing. Further, it is found that the impact is significantly strong in the slowdown, as financial constraints are more binding. These results seem to confirm that the balance-sheet channel of monetary transmission is operative in Poland.
Źródło:
Central European Economic Journal; 2020, 7, 54; 157 - 171
2543-6821
Pojawia się w:
Central European Economic Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Average Energy Slope Estimation Formulas for One-dimensional Steady Gradually Varied Flow
Autorzy:
Artichowicz, W.
Mikos-Studnicka, P.
Powiązania:
https://bibliotekanauki.pl/articles/241083.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
open channel
steady flow
gradually varied flow
standard step method
energy slope
Opis:
To find the steady flow water surface profile, it is possible to use Bernoulli’s equation, which is a discrete form of the differential energy equation. Such an approach requires the average energy slope between cross-sections to be estimated. In the literature, many methods are proposed for estimating the average energy slope in this case, such as the arithmetic mean, resulting in the standard step method, the harmonic mean and the geometric mean. Also hydraulic averaging by means of conveyance is commonly used. In this study, water surface profiles numerically computed using different formulas for expressing the average slope were compared with exact analytical solutions of the differential energy equation. Maximum relative and mean square errors between numerical and analytical solutions were used as measures of the quality of numerical models. Experiments showed that all methods gave solutions useful for practical engineering purposes. For every method, the numerical solution was very close to the analytical one. However, from the numerical viewpoint, the differences between the methods were significant, as the errors differed up to two orders of magnitude.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 3-4; 89--109
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cross-waves and pulsating flows in the side-channel spillway - an experimental approach
Autorzy:
Azmeri, Azmeri
Ummah, Chairatun
Jemi, Faris Zahran
Faudli, Imam
Nasaiy, Qurratul 'Aini Benti
Powiązania:
https://bibliotekanauki.pl/articles/2203528.pdf
Data publikacji:
2023
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
cross-waves
hydrodynamic force
physical model
pulsating flow
side-channel spillway
Opis:
Potentially hazardous side-channels of complex geometry need to be investigated using detailed hydraulic physical models. This study aims to analyse the cross-waves pattern and pulsating flow using a side-channel spillway physical model. This study compares the cross-waves pattern were measured using an experimental installation set to generate cross-waves on the surface (original series) with another structure that did not produce cross-waves (modified series). The results showed that the geometry of the left wall caused instability in flow patterns and secondary flows. The starting point of Q2 discharge was detected by minor turbulence on the water surface near the left wall at a water depth of 3.3 m at the starting point of the wall, but with no overtopping. Cross-waves formed downstream at the right wall crosswise, lower than at the left wall. The height of the cross-wave increased substantially from Q100 to Q1000 discharges leading to overtoppings near the left wall at a water depths of 4.2 and 5.0 m at the starting point of the wall, and near the right wall at a water depths of 3.8 and 4.0 m at the upstream point of the wall. The modifications provided optimal hydraulic conditions, i.e. elimination of cross-waves and non-uniform flows. The Vedernikov and Montouri numbers showed that both original and modified series did not enter the area where the pulsating flow occurred. This indicated that both series were free from the pulsating flow.
Źródło:
Journal of Water and Land Development; 2023, 56; 51--57
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Definition of dimensionless coefficient of resistance and coefficient of roughness in cross-section of stream with large roughness element
Autorzy:
Michalec, B.
Strutynski, M.
Powiązania:
https://bibliotekanauki.pl/articles/59718.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:
Rudawa River
Bedkowka Stream
stream
large roughness grain
dimensionless coefficient
roughness coefficient
hydraulic condition
water flow
flow channel bottom
flow channel distribution
Opis:
The results of investigations carried out in the stream Będkówka – a left bank tributary of the Rudawa River are presented in this paper. A stream sector with large roughness element was chosen for investigations. The performed measurements included cross-section leveling and longitudinal leveling of the stream channel, bed load (sediment) sampling, and hydrometric measurements. Cross section leveling included five cross-sections in the 19-m long stream sector; these were located upstream and downstream the large roughness element and in its region. Differentiation of flow velocity in the region of large roughness element and its influence on differentiation of the load granulometric composition in the stream channel was shown. Immediately downstream the large roughness grain zone a fine grain sediment was frapped, its diameter d50 was seven to ten times smaller than that of the sediment in bed present in the stream channel. The dimensionless coefficient of resistance was calculated taking into account the equivalent bottom roughness determined in each of the examined sections by use of Gladki`s formulae. It was found that the large roughness element in the Będkówka stream caused a change of hydraulic conditions of water flow and, in consequence, the dimensionless coefficient of resistance in the grain section increased by about four times. The coefficient of channel roughness was also determined and it was shown that the coefficient of roughness in the section of large roughness element determined with consideration of the determined dimensionless coefficient of resistance increased on the average in the section of large roughness grain by over 34% in relation to the coefficient of channel roughness.
Źródło:
Infrastruktura i Ekologia Terenów Wiejskich; 2010, 11
1732-5587
Pojawia się w:
Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 61

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