Temat: liquid-liquid flow - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Quantification of solid particle transport in suspension in a stream : Case of Wadi Zeddine Ain-Defla, Algeria
Autorzy:: Bouleknafet, Zohir
Elahcene, Omar
Powiązania:: https://bibliotekanauki.pl/articles/2203543.pdf
Data publikacji:: 2023
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: Algeria
sediment concentration
erosion
liquid flow
solid flow
suspension
Wadi Zeddine
Opis:: Arid and semi-arid areas are characterised by differentiation in meteorological conditions. Sometimes the rains are rare and not very intense and at other times they are dense and very intense, resulting in torrents that often lead to strong soil erosion. Most of the time, the losses occur at the solids level because the erosion effect is too high. In this study, we want to evaluate the transfer of solid sediments as a function of liquid transport in the basin of Wadi Zeddine at Ain Defla in Algeria. To understand this phenomenon, we used the data of liquid flows (Ql, m3∙s-1) and concentration of suspended sediments (C, g∙dm-3), transported in the river, the data collected by the NWRA (National Water Resources Agency), over 24 years have been used to find a relationship between these two quantities, to estimate the quantity of solid transport Qs (kg∙s-1) in the watercourse of the catchment area studied. The results obtained show a good correlation between solid and liquid flows, with a correlation coefficient estimated at 90%, and the average annual sediment supply recorded at the outlet of the Wadi Zeddine watershed is estimated at around 88,048 Mg, which corresponds to 202 Mg∙km-2∙y-1 erosion rate. This value is comparable to those found in other regions with similar hydrological regimes.
Źródło:: Journal of Water and Land Development; 2023, 56; 102--108
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Development of foam-breaking measures after removing liquid contamination from wells and flowlines by using surface-active substances
Autorzy:: Volovetskyi, V. B.
Doroshenko, Ya. V.
Stetsiuk, S. M.
Matkivskyi, S. V.
Shchyrba, O. M.
Femiak, Y. M.
Kogut, G. M.
Powiązania:: https://bibliotekanauki.pl/articles/2201061.pdf
Data publikacji:: 2022
Wydawca:: Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:: well
gas
flowline
liquid removal
gas-fluid flow
foam breaking
odwiert
gaz
linia przepływu
usuwanie cieczy
przepływ gaz-ciecz
Opis:: Purpose The purpose is to consider the complications that arise during the operation of gas condensate wells, in particular, the accumulation of liquid contamination. Development of new approaches to improve the efficiency of the separation equipment performance of gas gathering and treatment systems when a multiphase flow enters. Development of a foam breaking method in a gas-liquid flow after removal of liquid contaminants from wells and flowlines using surfactants. Design/methodology/approach An analysis was made of the complications that may arise when removing liquid contaminants from wells and flowlines using surfactants. Measures have been developed that will make it possible to timely prevent the ingress of foam into the separation equipment of gas gathering and treatment systems. Using computational fluid dynamics (CFD) modelling, an effective foam-breaking device was developed by supplying stable hydrocarbon condensate. Findings A method to minimize the negative impact of foam on the operation of separation equipment after fluid removal from wells and gas condensate field flowlines using a surfactant solution was elaborated. A method for its breaking was proposed to prevent the flow of foam into the gas processing unit. This method foresees the application of the technological scheme layout for supplying a stable hydrocarbon condensate to a gas-liquid flow entering the separators of the first of separation, both the main line and the measuring line. CFD modelling was used to study the process of foam breaking by feeding hydrocarbon condensate into it. The influence of the hydrocarbon condensate supplying method on gas-dynamic processes (distribution of pressure, velocity, volumetric particles of phases), and the efficiency of foam breaking was estimated. It was established that the supply of hydrocarbon condensate from one branch pipe to the pipeline through which the foam moved did not ensure its complete breaking. To increase the efficiency of foam breaking, a device with designed four nozzles for supplying hydrocarbon condensate was developed. CFD modelling made it possible to substantiate that in this case, a pressure reduction zone appeared at the place of condensate supply. Because of a sharp change in pressure, a strong improvement in the effect of foam breaking occurred. The understanding of the regularities of foam breaking processes by hydrocarbon condensate was obtained, and the design of a device for the complete foam breaking was developed. Research limitations/implications The obtained results of laboratory studies have shown that a sharp decrease in the stability of the foam occurs under the condition of an increase in the volume of stable hydrocarbon condensate added to the studied model of mineralized formation water. Based on the results of CFD modeling, a device for breaking foam by stable hydrocarbon condensate has been worked out, the effectiveness of which will be confirmed experimentally and in field conditions. Practical implications The results of the performed laboratory studies and CFD modelling allow a more reasonable approach to using various available methods and measures to prevent the ingress of foam with a gas-liquid flow into the separation equipment of gas gathering and treatment systems. This approach makes it possible to develop new effective ways and measures to prevent this complication. Originality/value Based on CFD modelling, it was found that when a stable hydrocarbon condensate is supplied into a gas-liquid flow, foam breaks. A method for breaking foam in a gas-liquid flow has been developed, which is original and can be introduced in practice.
Źródło:: Journal of Achievements in Materials and Manufacturing Engineering; 2022, 114, 2; 67--80
1734-8412
Pojawia się w:: Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Emptying sewage from the valve-pit sump through service lateral to vacuum main
Autorzy:: Błażejewski, Ryszard
Matz, Radosław
Powiązania:: https://bibliotekanauki.pl/articles/2171839.pdf
Data publikacji:: 2022
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: model of liquid flow
sewage manhole
sewer system
pumping system
pressure system
model przepływu cieczy
studzienka kanalizacyjna
system kanalizacyjny
system pompowy
system ciśnieniowy
Opis:: A simple hydraulic model of liquid and gas flow from a collecting sump via vacuum service lateral to a vacuum main has been presented. The model was formulated and validated on experimental data and CFD simulations. The standard gas (air) to liquid (sewage) volumetric ratio is roughly equal to the ratio of subsequent admittance times of these two phases, provided that the liquid plug is not fully sucked from the service lateral to the vacuum main during the valve open time. A longer air suction time is needed only when the service lateral is too short to provide enough air to transport the sewage past the nearest downstream lift on the vacuum main. Sizing properly the active sump volume and valve open time for a given service lateral length, one can provide the required air to liquid ratios along the vacuum main, thus minimizing the energy consumption by the vacuum pumps.
Źródło:: Environment Protection Engineering; 2022, 48, 3; 69--88
0324-8828
Pojawia się w:: Environment Protection Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Porównanie wyników metod pomiaru skuteczności usuwania osadu płuczkowego
A comparison of the results of methods for measuring the efficiency of mud removal
Autorzy:: Kremieniewski, Marcin
Powiązania:: https://bibliotekanauki.pl/articles/2145893.pdf
Data publikacji:: 2021
Wydawca:: Instytut Nafty i Gazu - Państwowy Instytut Badawczy
Tematy:: oczyszczanie
przestrzeń pierścieniowa
ciecz przemywająca
symulator przepływu cieczy wiertniczych
wiskozymetr
korelacja
osad płuczkowy
annular space
cleaning
washing liquid
drilling fluids flow simulator
viscometer
correlation
mud sludge
Opis:: Odpowiednie oczyszczenie przestrzeni pierścieniowej przed zabiegiem cementowania jest jednym z ważniejszych czynników mających wpływ na prawidłowe uszczelnienie kolumny rur okładzinowych. Nieodpowiednie lub niecałkowite usunięcie płuczki lub pozostałości osadu płuczkowego może skutkować powstawaniem niekontrolowanych wypływów gazu (migracji bądź ekshalacji) na kontakcie płaszcza cementowego z formacją skalną oraz z powierzchnią zapuszczonych rur okładzinowych. Związane jest to z brakiem kompatybilności płuczki i tłoczonego po niej zaczynu cementowego, co objawia się tworzeniem na ścianach otworu żelujących kanalików, umożliwiających przepływ gazu. Dodatkowo brak odpowiedniego oczyszczenia przestrzeni pierścieniowej powodował będzie obniżenie wartości przyczepności płaszcza cementowego do powierzchni styku. Wynikiem powyższego może być brak odpowiedniej stabilizacji kolumny rur poprzez osłabione jej zespolenie w dolnej części ze ścianą otworu, a w górnej części z poprzednią kolumną rur o większej średnicy. W związku z tym w celu poprawy zarówno szczelności odwiertu, jak też jakości stanu zacementowania prowadzi się badania laboratoryjne efektywności oczyszczania przestrzeni pierścieniowej poprzez pomiar skuteczności usuwania osadu płuczkowego. Dotychczas pomiar skuteczności usuwania osadu lub działania cieczy przemywającej prowadzony był przy użyciu wiskozymetru obrotowego. Podczas badania osad płuczkowy wytwarzany jest na powierzchni rotora, a następnie usuwany za pomocą cieczy przemywającej. W ostatnim czasie w INiG – PIB opracowano nową metodę pomiaru skuteczności usuwania osadu płuczkowego przez zastosowanie nowo zaprojektowanego symulatora przepływu cieczy wiertniczych (patent P.423842). Urządzenie pozwala na symulację przepływu cieczy wiertniczej (płuczki, cieczy przemywającej, buforu) w symulowanej przestrzeni pierścieniowej. Możliwy jest dobór parametrów przepływu (wydatku tłoczenia) oraz czasu kontaktu cieczy z badaną powierzchnią. Ze względu na zróżnicowanie zasad pomiaru podczas badań przy użyciu wiskozymetru i symulatora – postanowiono przeprowadzić badania porównawcze w celu określenia stopnia zbieżności omawianych metod. Badania polegały na ocenie skuteczności usuwania tego samego rodzaju osadu przez te same ciecze przemywające, lecz przy użyciu różnych metod pomiaru. Uzyskane wartości skuteczności usuwania osadu poddano analizie korelacyjnej, na podstawie której możliwe było porównanie wyników analizowanych metod pomiaru.
The proper cleaning of the annular space before cementing is one of the most important factors affecting the proper sealing of the casing column. Inadequate or incomplete removal of the mud cake or residues of the mud may result in the formation of uncontrolled gas outflows (migration or exhalation) at the contact of the cement sheath with the rock formation and with the surface of run-down casing. It is related to the lack of compatibility in the contact of the mud and the cement. Additionally, the lack of proper cleaning of the annular space will reduce the adhesion value of the cement sheath to the contact surface. The result of the above may be the lack of adequate stabilization of the column of pipes due to its weakened connection in the lower part with the wall, and in the upper part with the previous column of larger diameter pipes. Therefore, to improve both the tightness of the borehole as well as the quality of the cementation condition, laboratory tests of the efficiency of cleaning the annular space are carried out by measuring the efficiency of washing mud removal. So far, measuring the efficiency of mud removal or the effect of washing utilization have been done using a rotary viscometer. During the test, a mud cake is produced on the rotor surface and then removed with washing liquid. Recently, the Oil and Gas Institute – National Research Institute developed a new method for measuring the efficiency of drilling mud removal by using a newly developed drilling fluid flow simulator (Patent P.423842). The device enables the simulation of the drilling fluid flow (drilling fluid, washing fluid, spacer) in the simulated annular space. It is possible to select the parameters of the flow (delivery rate) and the contact time of the liquid with the tested surface. Due to the different measurement principles during the tests with the viscometer and the simulator, it was decided to conduct a comparison and determine the degree of convergence of the discussed methods. The same rinsing liquids were tested to remove the same type of mud, but using different measurement methods. The obtained values of mud removal efficiency were subjected to the correlation analysis, which made it possible to compare the results of the analyzed measurement methods.
Źródło:: Nafta-Gaz; 2021, 77, 1; 34-46
0867-8871
Pojawia się w:: Nafta-Gaz
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Influence of Modern Ladle Shroud on Hydrodynamic Structure in One Strand Slab Tundish
Autorzy:: Bartosiewicz, M.
Cwudziński, A.
Powiązania:: https://bibliotekanauki.pl/articles/352375.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: continuous steel casting
tundish
ladle shroud
liquid steel flow
turbulence models
Opis:: In the presented work, the numerical simulations results of the liquid steel flow in the one strand tundish were shown. Influence of the modification and immersion depth in the liquid steel of the ladle shroud and subflux turbulence controller on hydrodynamic structure of the liquid steel movement in the working space of tundish were examined. The ladle shroud shape modification consisted on the decompression and compression of the main supplying stream of the tundish. The mathematical model used in the numerical simulations through physical modeling and industrial trials were validated. The numerical simulation results (using four variants of the modified ladle shroud immersion depth in the liquid steel) in the isothermal conditions using laboratory experiments on the water model were verified. Whereas, the numerical simulation results (using one of the tundish research variant) for non-isothermal were compared with the results from the industrial measurements. Three turbulence models: Realizable k-ε, RNG k-ε and SST k-ω were used in the computer calculations (performed via the Ansys-Fluent computer program). In order to obtain the actual view of the liquid steel flow hydrodynamic structure in the examined tundish for the two mathematical models using different turbulence models, which were most similar to the laboratory experiments and industrial measurements, the numerical simulations were performed in the non-isothermal conditions. The application in the computer calculations of the SST k-ω turbulence model caused the smallest differences between the numerical simulations, laboratory experiments and industrial measurements. Performed tests showed that ladle shroud can be used as a flow control device and the modified ladle shroud immersion at a depth of 0.1 m in the liquid steel caused the shortest range of the transition zone among the tested cases.
Źródło:: Archives of Metallurgy and Materials; 2020, 65, 1; 27-37
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Optimization the operation parameters of SDA desulfurization tower by flow coupling chemical reaction model
Autorzy:: Mei, Dan
Shi, Junjie
Zhu, Yuzheng
Xu, Xuemei
Xing, Futang
Shi, Ling
Powiązania:: https://bibliotekanauki.pl/articles/778336.pdf
Data publikacji:: 2020
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:: spray drying absorber tower
gas-liquid two-phase flow
droplet diameter
desulfurization efficiency
amount of scaling
Opis:: Spray Drying Absorber (SDA) has been widely used for large-scale desulfurization. However, it also has some limitations. For example, the liquid absorbent easily causes scaling, which impedes the contact between the serous fluid and the flue gas and reduces the chemical reaction rate and desulfurization efficiency. This paper establishes the mathematical and physical model of gas and liquid two-phase flow and droplet evaporation and heat transfer in rotary spray desulfurization tower. To study the accumulation and distribution of chemical reaction precipitates in the desulfurization tower and analyze the removal efficiency of sulfur dioxide (SO²) in different atomization diameters, this paper establishes a simulation model concerning the coupling of desulfurization reaction and flow field calculation based on the absorption and reaction mechanism of SO². Baffle in different widths are set to optimize the internal floweld and balance the distribution of flue gas. By setting baffles of different widths to optimize the flow feld in the tower and changing the distribution of flue gas, this model reduces the scaling while ensuring the desulfurization efficiency. The results of the simulation experiment have verified that the droplet with a diameter of 50 μm is the optimal option, which can effectively remove the scaling and ensure that the desulfurizing tower runs in high efficiency and stability. When the width of baffes is 2250 mm, the efficiency of desulfurization exceeds 95%, and the amount of scaling on the desulfurization tower main wall is controlled at the minimum level, which is the optimal option for production.
Źródło:: Polish Journal of Chemical Technology; 2020, 22, 1; 35-45
1509-8117
1899-4741
Pojawia się w:: Polish Journal of Chemical Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Analiza termo-optyczna (TOA) jako narzędzie badań zjawisk topnienia
Thermo-optical analysis (TOA) as a tool of melting phenomena investigations
Autorzy:: Galewski, Zbigniew
Korbecka, Izabela
Osiecka-Drewniak, Natalia
Powiązania:: https://bibliotekanauki.pl/articles/171758.pdf
Data publikacji:: 2019
Wydawca:: Polskie Towarzystwo Chemiczne
Tematy:: kalorymetria adiabatyczna
kalorymetria DSC z kompensacją ciepła
kalorymetria DSC z przepływem ciepła
modulacyjna kalorymetria
MDSC
różnicowa analiza termiczna
DTA
ciekłe kryształy
mezogeny
fazy rotacyjne
adiabatic calorimetry
DSC calorimetry with heat compensation
DSC calorimetry with heat flow
modulation calorimetry
differential thermal analysis
liquid crystals
mesogens
rotational phases
Opis:: In the work, after preliminary discussion of the complexity of the phenomenon of melting chemical compounds, two basic research methods are presented: calorimetric methods and thermooptical method. The physical basis of the five main calorimetry techniques is now detailed (adiabatic calorimetry, differential thermal analysis – DTA, differential scanning calorimetry with heat compensation – DSC heat compensated, differential scanning calorimetry with heat flow – DSC heat flux and differential scanning calorimetry with temperature modulation – MDSC) and thermo-optical techniques used in phase transitions investigations. The advantages and disadvantages of these methods are shown in numerous examples and the accuracy attainable by the individual measuring techniques is compared.
Źródło:: Wiadomości Chemiczne; 2019, 73, 3-4; 202-220
0043-5104
2300-0295
Pojawia się w:: Wiadomości Chemiczne
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Design and simulation of a multienergy gamma ray absorptiometry system for multiphase flow metering with accurate void fraction and water-liquid ratio approximation
Autorzy:: Khayat, Omid
Afarideh, Hossein
Powiązania:: https://bibliotekanauki.pl/articles/147267.pdf
Data publikacji:: 2019
Wydawca:: Instytut Chemii i Techniki Jądrowej
Tematy:: multiphase flow measurement
void fraction
water-liquid ratio
flow regime
MCNP
artificial neural network
reżim przepływu
sztuczna sieć neuronowa
Opis:: Multiphase flow meters are used to measure the water-liquid ratio (WLR) and void fraction in a multiphase fluid stream pipeline. In the present study, a system of multiphase flow measurement has been designed by application of three thallium-doped sodium iodide scintillators and a radioactive source of 133Ba simulated by Monte Carlo N-particle (MCNP) transport code. In order to capture radiations passing across the pipe, two direct detectors have been installed on opposite sides of the radioactive source. Another detector has been placed perpendicular to the transmission beam emitted from the 133Ba source to receive radiations scattered from the fluid flow. Simulation was done by the MCNP code for different volumetric fractions of water, oil, and gas phases for two types of flow regimes, namely, homogeneous and annular; training and validation data have been provided for the artificial neural network (ANN) to develop a computation model for pattern recognition. Depending on applications of the neural system, several structures of ANNs are used in the current paper to model the flow measurement relations, while the detector outputs are considered as the input parameters of the neural networks. The first, second, and third structures benefit from two, three, and five multilayer perceptron neural networks, respectively. Increasing the number of ANNs makes the system more complicated and decreases the available data; however, it increases the accuracy of estimation of WLR and gas void fraction. According to the results, the maximum relative difference was observed in the scattering detector. It was clear that transmission detectors would demonstrate the difference between the flow regimes as well. It is necessary to note that the error calculated by the MCNP simulator is <0.5% for the direct detectors (TR1 and TR2). Due to the difference between the data of the two flow regimes and the errors of data in the simulation codes of the MCNP, it was possible to separate these flow regimes. The effect of changing WLR on the efficiency for a constant void fraction confi rms a considerable variance in the results of annular and homogeneous flow s occurring in the scattering detector. There is a similar trend for the void fraction; hence, one can easily distinguish changes in efficiency due to the WLR. Analysis of the simulation results revealed that in the proposed structure of the multiphase flow meter and the computation model used for simulation, the two flow regimes are simply distinguishable.
Źródło:: Nukleonika; 2019, 64, 1; 19-29
0029-5922
1508-5791
Pojawia się w:: Nukleonika
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Influence of multi-hole filter modification on the flow hydrodynamic structure and refining process of liquid steel in the one-strand tundish
Autorzy:: Bartosiewicz, M.
Cwudziński, A.
Powiązania:: https://bibliotekanauki.pl/articles/356431.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: tundish
continuous steel casting
multi-hole filter
liquid steel flow
non-metallic inclusions
Opis:: In this work, the authors proposed a modification of the working space one-strand tundish adapted for slab casting process. Numerical simulations of liquid steel flow in the considered flow reactor were performed. The tundish is equipped with a dam with a multi-hole filter. Two variants of the filter hole arrangement were tested and their effect on the liquid steel flow hydrodynamic structure in the tundish was examined. The computer calculations results were verified by performing experiments on the water model. The result of numerical and physical simulations an RTD (Residence Time Distribution) type F curve was generated, which define the transition zone between the cast steel grades during the sequential casting process. The results of the researches showed that the modification of a dam with a multi-hole filter affects on the formation of the liquid steel flow hydrodynamic structure and the transition zone. Furthermore, examinations of the liquid steel refining ability in the considered tundish were carried out. The influence of the filter holes arrangement on the non-metallic inclusions flotation process to the slag phase and liquid steel filtration processes was checked. Numerical simulations were performed in the Ansys-Fluent computer program.
Źródło:: Archives of Metallurgy and Materials; 2019, 64, 1; 71-78
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: New gas-liquid two-phase flow pattern maps based on the energy ratio of pressure fluctuation through a Venturi tube
Autorzy:: Sun, Zhiqiang
Chen, Luyang
Yao, Fengyan
Powiązania:: https://bibliotekanauki.pl/articles/220955.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: gas-liquid two-phase flow
flow pattern map
Venturi tube
pressure fluctuation
energy ratio
ensemble empirical mode decomposition
Opis:: To find effective and practical methods to distinguish gas-liquid two-phase flow patterns, new flow pattern maps are established using the differential pressure through a classical Venturi tube. The differential pressure signal was first decomposed adaptively into a series of intrinsic mode functions (IMFs) by the ensemble empirical mode decomposition. Hilbert marginal spectra of the IMFs showed that the flow patterns are related to the amplitude of the pressure fluctuation. The cross-correlation method was employed to sift the characteristic IMF, and then the energy ratio of the characteristic IMF to the raw signal was proposed to construct flow pattern maps with the volumetric void fraction and with the two-phase Reynolds number, respectively. The identification rates of these two maps are verified to be 91.18% and 92.65%. This approach provides a cost-effective solution to the difficult problem of identifying gas-liquid flow patterns in the industrial field.
Źródło:: Metrology and Measurement Systems; 2019, 26, 2; 241-252
0860-8229
Pojawia się w:: Metrology and Measurement Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: The Influence of Riser Shape on Feeding Effectiveness of Solidifying Casting
Autorzy:: Sowa, L.
Skrzypczak, T.
Kwiatoń, P.
Powiązania:: https://bibliotekanauki.pl/articles/383146.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: solidification process
castings defects
numerical simulation
liquid metal flow
proces krzepnięcia
wady odlewów
symulacja numeryczna
przepływ ciekłego metalu
Opis:: The mathematical model and numerical simulations of the solidification of a cylindrical shaped casting, which take into account the process of filling the mould cavity by liquid metal and feeding the casting through the riser during its solidification, are presented in the paper. Mutual dependence of thermal and flow phenomena were taken into account because have an essential influence on solidification process. The effect of the riser shape on the effectiveness of feeding of the solidifying casting was determined. In order to obtain the casting without shrinkage defects, an appropriate selection of riser shape was made, which is important for foundry practice. Numerical calculations of the solidification process of system consisting of the casting and the conical or cylindrical riser were carried out. The velocity fields have been obtained from the solution of momentum equations and continuity equation, while temperature fields from solving the equation of heat conductivity containing the convection term. Changes in thermo-physical parameters as a function of temperature were considered. The finite element method (FEM) was used to solve the problem.
Źródło:: Archives of Foundry Engineering; 2019, 4; 91-94
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Wpływ kształtu kryzy na pomiar różnicy ciśnienia przy przepływie strumienia mieszaniny gaz - ciecz
Effect of orifice design on differential pressure measurement in two two phase air-water mixture flow
Autorzy:: Tomaszewska-Wach, Barbara
Rząsa, Mariusz R.
Dobrowolski, Bolesław
Powiązania:: https://bibliotekanauki.pl/articles/267049.pdf
Data publikacji:: 2019
Wydawca:: Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:: kryza pomiarowa
kryza szczelinowa
pomiar strumienia gazu
mieszanina powietrze-woda
standard orifice
slotted orifice
gas mass flowrate
two phase flow
air-liquid flow
Opis:: Pomiar gazu metodą zwężkową jest bardzo często stosowany w pomiarach przemysłowych. Podczas przepływu gazu niejednokrotnie dochodzi do wykroplenia się cieczy. W efekcie zamiast przepływu jednofazowego mierzy się mieszaninę gaz – ciecz. Z tego powodu pojawiają się błędy wskazań przyrządów pomiarowych wynikające ze zmiany właściwości fazy ciągłej, którą jest gaz. Ponadto pojawienie się dodatkowej fazy prowadzi do powstawania zaburzeń przepływu i pulsacji ciśnienia. Dlatego poszukuje się nowych metod i narzędzi do pomiaru przepływu mieszaniny gaz-ciecz, które umożliwiają uzyskanie zadowalającej dokładność pomiaru, w momencie gdy pojawia się zakłócenie w postaci fazy ciekłej. Zakres badań przedstawionych w obecnej pracy obejmował zastosowanie kryz szczelinowych do pomiaru mieszanin gaz-ciecz. Przeprowadzona została analiza wpływu geometrii kryzy szczelinowej na pomiar strumienia mieszaniny dwufazowej. Badaniom eksperymentalnym poddano kryzę standardową oraz dwie konstrukcje kryz szczelinowych o różnej geometrii otworów. Eksperyment obejmował pomiar przepływu powietrza z niewielką ilością wody rozproszonej w postaci kropel. Wyniki badań porównano z wynikami uzyskanymi dla kryzy standardowej.
Gas measurements employing various slotted orifice designs are often employed in industrial applications. In the conditions of gas flow in the pipelines, we have to do with liquids condensation. As a result, the flow measurements basically involve gas-liquid mixture. For this reason, considerable errors occur in the measurement conducted by instruments resulting from the variations in the properties of the continuous phase, which is formed by gas. In addition, the occurrence of an additional phase results in flow interferences and pulsations of differential pressure. Therefore, new methods and tools are being sought with the aim of measuring the flow of gas-liquid mixtures, which will provide satisfactory accuracy of measurements in the case when flow interference occurs in the form of the liquid phase. The paper reports the results of a study concerned with the use of slotted orifices in the conditions of measurements of gas-liquid mixtures. Experimental research was carried out by application of a standard orifice and two designs of the slotted orifice with various slot geometries. The experiment involved the measurement of the air flow with a small amount of water, which was dispersed in the form of droplets. The results of the experiment were subsequently compared with the results recorded for the case of a standard orifice. The occurrence of liquid in the constant flow of air leads to the variations in the differential pressure developed at the orifice. As a result of the greater mass flow rate of water in the air flow, the value of the differential pressure developed at the orifice is the greater as well . In the conditions of the measurements of two-phase mixture, slotted orifice generate a smaller differential pressure compared to the standard orifice. Slotted orifices also demonstrate lower sensitivity to the variations in the flow rate of liquid in the gas. This is due to the fact that in this type of designs, we have to do with a local change in the beta ratio across the entire cross-section of the pipeline. The liquid droplets are entrained along with the air flow and freely pass through the obstacle, and only a small amount of liquid is held-up at the orifice. The gaps that are located across the entire volume of the tube allow the liquid drops to be carried away again by the gas stream in contrast to the standard solution. During flow measurements involving mixtures by the application of the standard orifice, an additional difficulty is associated with the fact that a large portion of the liquid is stopped at the orifice, as the flowing liquid accumulates in front of the orifice causing flow disturbances.
Źródło:: Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2019, 66; 85-89
1425-5766
2353-1290
Pojawia się w:: Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Badanie deformacji kropel z wymianą masy w prostym przepływie ścinającym
Investigation on drop deformation with mass transfer in simple shear flow
Autorzy:: Jasińska, M.
Mańkowski, M.
Powiązania:: https://bibliotekanauki.pl/articles/2073329.pdf
Data publikacji:: 2018
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:: deformacja kropli
wymiana masy
przepływ ścinający
układy ciecz-ciecz
drop deformation
mass transfer
shear flow
liquid-liquid systems
Opis:: Przedstawiono symulacje numeryczne deformacji kropli w prostym przepływie ścinającym. Obliczenia wykonano dla liczb kapilarnych mniejszych od wartości krytycznych gwarantujących deformację kropli bez jej rozpadu. W pracy badano zachowanie się kropli w przypadku obecności ścianek ograniczających układ, a wyniki symulacji porównano z wynikami doświadczalnymi opublikowanymi w literaturze. Wykonane symulacje pozwoliły również na określenie współczynników transportowych dla wymiany masy. Wartości tych współczynników zweryfikowano z wykorzystaniem modelu Favelukisa i Lavrentevej.
In this work the numerical simulation of drop deformation in a simple shear flow is presented. Calculations were made for capillary numbers smaller than critical, providing a pure deformation of droplet and excluding possibility of its breakage. The deformation of droplet in a confined system was investigated and compared with experimental data published in literature. The performed simulations allowed also the estimation of mass transfer coefficients. Their values were verified using the Favelukis and Lavrenteva model.
Źródło:: Inżynieria i Aparatura Chemiczna; 2018, 5; 131--132
0368-0827
Pojawia się w:: Inżynieria i Aparatura Chemiczna
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Experimental observations of flow structures during DEP controlled boiling in a microchannel
Autorzy:: Lackowski, M.
Kwidziński, R.
Karwacki, J.
Przybyliński, T.
Powiązania:: https://bibliotekanauki.pl/articles/240808.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: visualisation
liquid dielectrophoresis
flow control
flow structures
wizualizacja
sterowanie
przepływ
struktury przepływu
Opis:: The paper presents results of experimental investigation of microchannel boiling flow which was controlled by dielectrophoretic (DEP) restrictor. The DEP restrictor was connected to the microchannel liquid supply tube. Operation of DEP restrictor influenced the flow rate at the microchannel inlet. Resulting changes in flow structures and vapour content along the microchannel were observed and analysed with a high-speed video camera. Video recordings were synchronised with measurements of differential pressure between the channel inlet and outlet. It was found that it is possible to change average void fraction in the microchannel by switching on and off the voltage applied to the restrictor electrodes. However, to achieve significant variation of the void fraction, applied voltage should be of the order of 2000 Vpp. The voltage switching also generates oscillations of the differential pressure. The amplitude of these oscillations is proportional to the voltage magnitude, reaching 35 Pa for 2400 Vpp.
Źródło:: Archives of Thermodynamics; 2018, 39, 1; 129-145
1231-0956
2083-6023
Pojawia się w:: Archives of Thermodynamics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Numerical modelling of combustion process with the use of ANSYS FLUENT code
Autorzy:: Kowalski, M.
Jankowski, M.
Powiązania:: https://bibliotekanauki.pl/articles/245622.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: liquid fuels
combustion processes
turbulent flow
combustion process model
ANSYS FLUENT
Opis:: The article presents the modelling of the combustion process of liquid fuels using professional ANSYS FLUENT software. This program allows modelling the dynamics of compressible and incompressible, laminar and turbulent flows as well as heat exchange phenomena with occurrence and without chemical reactions. The model presented in the article takes into account the influence of the gas phase on the liquid phase during the fuel combustion process. The influence of velocity and pressure of the flowing gas and the type of flow has a significant impact on the combustion of liquid fuels. The developed model is fully reliable and the presented results are consistent with experimental research. The occurrence of a laminar sublayer in a turbulent flow was confirmed, and the thickness of this layer and the turbulent layer significantly influences the course of the combustion process. The use of the flat flow model reflects the basic phenomena occurring during the combustion of liquid fuels under turbulent conditions. The use of the program for flows with different flow velocity profiles is justified. It gives important information about the processes taking place during the combustion of liquid fuels. The results of numerical tests are presented graphically. The article presents graphs of velocity field, absolute pressure, power lines, temperature and density.
Źródło:: Journal of KONES; 2018, 25, 4; 175-186
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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