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1

Effect of Swirl Angle on Interaction between Swirl Oxygen Lance Jet and Melt Pool

Ma Haoran, Liu Guangqiang, Xu Chengcheng, Liu Kun, Han Peng

Archives of Foundry Engineering

|

2024

|

Vol. 24, iss. 1

50--57

EN

In order to clarify the action law of the swirl oxygen lance jet on the melt pool of the converter and to determine the optimal swirl angle of the swirl oxygen lance for the 120t converter, this study establishes the gas-liquid two-phase flow model of the oxygen lance with different swirl angles based on the realizable k-ε model and the VOF multiphase flow model. The gas-liquid interface behavior during the interaction between the jet and the molten pool was analyzed, and the flow pattern of molten steel in the molten pool was mainly investigated. The results show that compared with traditional oxygen lance, the rotating oxygen lance jet enhances the stirring of the melt pool and intensifies the fluctuation of the melt pool liquid level. The depth of the impact cavity decreases with the increase of the swirl angle, but the diameter of the impact cavity increases with the increase of the swirl angle. When the jet with a swirl angle of 10° impacts the surface of the melt pool, the turbulence energy obtained by the molten steel is the highest, the average flow velocity inside the melt pool is the highest, and the molten steel is stirred more thoroughly, achieving better melting effects.

2

A Mean-Line Flow Model of Viscous Liquids in a Vortex Pump

Li Wenguang

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2022

|

Vol. 26, No 2

1--18

EN

The axial, radial and tangential velocity profiles of six fluids were extracted from computational fluid dynamics simulation results at points in a pump chamber 1 mm distant from the blades in a vortex pump at the specific speed of 76. The critical radius was specified in the axial velocity radial profiles to determine the impeller inlet and outlet at six viscosities and part-load, design, and over-load points. A mean-line flow model and hydraulic loss model were built from the profiles. The incidence, incidence loss in the inlet, deviation angle, and slip factor in the outlet were calculated. The impeller theoretical head, pump hydraulic efficiency and volumetric efficiency were analyzed. It was shown that the axial, radial and tangential velocity profiles relate closely to the flow rate as usual, but also the viscosity, especially at low flow rates and in the inlet. The low flow rate and viscosity lead to near zero axial and radial velocities, a faster tangential velocity than the blade speed, negative incidence, and a small incidence loss coefficient in the inlet. The dimensionless critical radius ranged within 0.77–0.89 and reduces with the increasing flow rate and viscosity. The mean slip factor is between 0.11 and 0.20 and rises with the increasing flow rate and viscosity. The mean incidence loss coefficient is within 0.0020–0.15 and augments with the increasing flow rate but increases with the decreasing viscosity under part-load conditions. The theoretical head estimated by using the fluid tangential velocity between the outlet of the impeller and the inlet of the chamber is more reasonable.

3

Experimental investigation of flow pattern over a fully developed bed at a 60° river confluence in large foods

Balouchi Behnam, Shafai Bejestan Mahmood, Ruther Nils, Rahmanshahi Mostafa

Acta Geophysica

|

2022

|

Vol. 70, no 5

2283--2296

EN

River confluences have a complex flow and sedimentation pattern that have vital influences on the hydraulic and bed morphology of river reach and the surrounding area. Confluences can be observed in waterways with various situations such as live bed conditions. This condition is a hydro-morphological situation with a high densiometric Froude number, i.e., bed load transport is supplied from upstream. According to the literature review, most of the experimental studies investigate the flow pattern on the flatbed and not on the developed riverbed, or/and in the low densiometric Froude number, or/and without supplying the sediment from upstream. Therefore, in the present study for the quantification of the flow pattern under these conditions, each developed bed was fixed with the cement blanket method in the laboratory. Then, the 3D velocity was measured at specific points at the confluence. The current study was designed to understand the flow pattern corresponding to the river bed behavior in the case of large foods. It is expected that the morphological features downstream of the confluence have a different pattern than the ones in the condition described in other literature. Thus, this paper describes briefly what are the different bed features and investigates the corresponding flow pattern. The results of the flow pattern on the developed bed show that all zones at the river confluence can be observed except the point bar due to the approximate equality of the mean longitudinal velocity of the separation zone and the main channel upstream of the confluence. Moreover, results show that by increasing the bedload ratio (sediment discharge to water discharge of the main channel of upstream of the confluence) from 0 to 3× 10−4, for defection to the outer bank of the channel decreased down to 45%, the stagnation equivalent area decreased down to 2.5 times, and bed shear stress decreased down to 40%. Hence, the momentum of lateral flow decreased with increasing bedload. Besides, the recovery zone occurred at a longer distance after the confluence compared to the case without bedload. Hence, the location of the maximum velocity zone, vortices, and secondary flows changed downstream of the confluence, by changing the bed load value.

4

Analogue modelling of flow patterns in bobbin friction stir welding by the dark-field/bright-field illumination method

Tamadon A., Pons D. J., Clucas D.

Advances in Materials Science

|

2020

|

Vol. 20, nr 1(63)

56--70

EN

The flow-inducing effect of the bobbin-tool features (tri-flat pin and scrolled shoulder) were replicated by a simple analogue model for aluminium welds by layered plasticine samples. Flow patterns of the weld zone were clarified by a typical stereomicroscopy instrument assisted by dark-field/bright-field illumination. The effects of the pin features, specifically threads and flats in centre of bond zone and scrolled shoulder in sides of stirred zone, were identified. This study shows that internal flow features for BFSW welds is transferable from the friction stir welding process to the functional metal forming processes such where the shearing can extensively affect the microstructure. The similarity between the flow pattern of the provided aluminium samples and the plasticine analogue can validate the accuracy of the flow model presented in this work.

5

Model przepływu i transportu jako narzędzie rozwiązywania problemu zanieczyszczeń wód podziemnych w rejonie Celsa Huta Ostrowiec

Sinicyn G., Grodzka-Łukaszewska M.

Biuletyn Państwowego Instytutu Geologicznego

|

2018

|

nr 471, Hydrogeologia, z. 15

147--158

PL

W artykule przedstawiono problem środowiskowy jaki wystąpił na obszarze wokół Celsa Huta Ostrowiec, gdzie w studniach ujmujących wody górnej jury wykryto podwyższone wartości stężeń trichloroetenu oraz tetrachloroetenu. Trójwymiarowy model numeryczny przepływu wód podziemnych i pola stężeń trichloroetenu został skalibrowany metodą „prób i błędów”. Podczas kalibracji brano pod uwagę kryterium dopasowania wyników stężeń zanieczyszczeń – obliczonych za pomocą modelu – do wyników stężeń zanieczyszczeń – pomierzonych w studniach oraz w piezometrach obserwacyjnych. Badania modelowe przeprowadzono dla różnych scenariuszy, uwzględniających zarówno typ zanieczyszczenia (punktowy oraz powierzchniowy), jak i czas trwania wycieku (incydentalny oraz ciągły w czasie). Przeprowadzone obliczenia modelowe pozwoliły na wskazanie najbardziej prawdopodobnego miejsca i czasu przedostania się zanieczyszczeń do środowiska wód podziemnych.

EN

The article presents the environmental problem that occurred in the vicinity of Celsa Huta Ostrowiec, where concentrations of trichloroethene and tetrachloroethene in wells were detected. The three-dimensional numerical groundwater flow and transport models were calibrated against trichloroethene measurements. Model studies were carried out for different scenarios taking into account the type of pollution source (point and spatial distributed) and the nature of the source itself (incidental and continuous in time). The modelling results made it possible to indicate the most likely place and time of contaminant release into the soil and water environment.

6

Flow structures during refrigerants condensation

Sikora M.

Journal of Mechanical and Energy Engineering

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2017

|

Vol. 1, No 1

101--106

EN

For several years, in the world are carried out studies on the refrigerants condensation in minichannels. These studies are aimed at understanding the condensation process and facilitate the design of mini heat exchangers. It is very important to optimize heat transfer and drive power consumption of the is the knowledge of the processes occurring during refrigerants condensation in pipe minichannels. It is important in this case to make a individual flow structures maps for the refrigerants, due to the significant effect of flow structured formed in the minichannel on the heat transfer and flow resistance. Unfortunately, in relation to the number of publications about condensation in minichannels, the number of published flow maps is relatively small. Due to the fact that the condensation process takes place differently in the minichannels and conventional channels, there is no possibility of using the flow maps for conventional channels to identification flow patterns in minichannels. One of the most popular flow maps for the condensation in minichannels is the map created by Colleman and Garimella, which was made for the R134a refrigerant. The authors conducted their own experimental studies of refrigerants R134a, R404A and R407C condensation in pipe minichannels with an internal diameter d = 3.3 - 0.31 mm. These studies results were subjected to calculation identification of flow structures using the map of Colleman and Garimella. These results are compared with the criteria published on Thome and Cavallini flow maps.

7

Rurociągowy transport CO2 na potrzeby geologicznej sekwestracji

Chaczykowski M., Osiadacz A. J.

Gaz, Woda i Technika Sanitarna

|

2017

|

Nr 10

388--391

PL

W artykule omówiony został aktualny stan badań nad technologią rurociągowego transportu CO2 na potrzeby sekwestracji na tle dojrzałych technologii rurociągowego transportu gazu ziemnego oraz rurociągowego transportu CO2 w celu intensyfikacji wydobycia ropy naftowej (EOR). Zaprezentowane zostały modele ustalonego i nieustalonego, nieizotermicznego przepływu CO2 w stanie nadkrytycznym oraz wyniki obliczeń hydraulicznych rurociągów, uzyskane przez autorów pracy z wykorzystaniem metod numerycznych. Ponadto, omówiony został wpływ zanieczyszczeń w mieszaninach CO2 , powstałych w wyniku stosowania różnych metod wychwytywania, na procesy cieplne i przepływowe w rurociągu.

EN

This article briefly discusses the current state of research on pipeline transport of CO2 for geological sequestration on a background of mature technologies of natural gas pipeline transport and CO2 pipeline transport for Enhanced Oil Recovery. Steady-state and transient, nonisothermal flow models in supercritical state are formulated and the results of their solutions using numerical methods are presented. The effect of impurities in CO2 mixtures (resulting from the use of various capture methods) on thermal-flow processes in the pipeline is shown.

8

Modelowanie fizykochemicznych procesów przemysłowych na przykładzie saturatora piekarniczego

Holiczer A., Malinowski G.

Przegląd Elektrotechniczny

|

2015

|

R. 91, nr 9

268-272

PL

Poniższy artykuł prezentuje próbę opracowania modeli matematycznych procesów fizykochemicznych występujących w saturatorze piekarniczym. Założeniem było opracowanie urządzenia służącego do dozowania wody nasyconej dwutlenkiem węgla w temperaturze nieprzekraczającej 40 C. Opracowano model opisujący zależność przepływu masowego mieszaniny cieczy i gazu w funkcji ciśnienia roboczego oraz algorytm dozowania wody gorącej do otrzymanej mieszaniny w celu uzyskania zadanej temperatury. Zaproponowane modele zostały pozytywnie zweryfikowane przy pomocy powstałego w wyniku prac mobilnego urządzenia do saturacji i dozowania wody w procesie przemysłowym.

XX

The paper deals with an attempt to develop mathematical models of physicochemical processes, which are occurring in a bakery aerator. The assumption is to design an equipment for dosing water saturated with carbon dioxide at a temperature not exceeding 40 C. The model is developed to describe the relationship between the mass flow of a mixture of liquid and gas as a function of the mixture pressure. Additionally, hot water dispensing algorithm is developed, so the output mixture preset temperature is obtained. The proposed models have been positively verified using a real mobile equipment for saturation and dispensing water in the industrial process.

9

Weryfikacja modelu stacjonarnego przepływu gazu w rurociągu

Chaczykowski M., Zarodkiewicz P.

Gaz, Woda i Technika Sanitarna

|

2014

|

Nr 8

294--298

PL

W artykule analizowano modele przepływu gazu pozwalające określać profile zmian ciśnienia i temperatury wzdłuż gazociągów w stanach ustalonych. Numeryczne rozwiązanie modelu dokładnego porównano z analitycznymi rozwiązaniami dwóch modeli uproszczonych o różnym stopniu złożoności i dokładności. Wyniki obliczeń weryfikowano na zbiorze danych rzeczywistych obejmujących dwa gazociągi wysokiego ciśnienia należące do krajowego systemu przesyłowego gazu ziemnego.

EN

In the paper pipeline gas flow models allowing for the determination of pressure and temperature profiles along the pipelines under steady-state conditions were analyzed. Numerical solution of the accurate model was compared with two analytical solutions of the simplified models of different complexity and accuracy. The calculation results were verified on a set of real data covering two high pressure gas transmission pipelines from within the polish gas transmission system.

10

Some problems of hydrodynamics of two-phase flow mixtures in minichannels

Wengel M., Miłaszewicz B., Ulbrich R.

Archives of Thermodynamics

|

2014

|

Vol. 35, no. 2

93--101

EN

Gas-liquid two-phase flow in minichannels has been the subject of increased research interest in the past few years. Evaluation, however, of today's state of the art regarding hydrodynamics of flow in minichannels shows significant differences between existing test results. In the literature there is no clear information regarding: defining the boundary between minichannels and conventional channels, labelling of flow patterns. The review of literature on the hydrodynamics of gas-liquid flow in minichannels shows that, despite the fact that many research works have been published, the problem of determining the effect of diameter of the minichannel on the hydrodynamics of the flow is still at an early stage. Therefore, the paper presents the results of research concerning determination of flow regime map for the vertical upward flow in minichannels. The research is based on a comprehensive analysis of the literature data and on the research that has been carried out. Such approach to the mentioned above problems concerning key issues of the two-phase flow in minichannels allowed to determine ranges of occurrence of flow structures with a relatively high accuracy.

11

Kalibracja modelu przepływu wód podziemnych na przykładzie ujęcia miejskiego w Koninie

Grodzka M., Treichel W.

Gospodarka Wodna

|

2013

|

Nr 8

311--316

PL

Przedstawiono proces tworzenia i kalibracji modelu przepływu wód podziemnych w rejonie ujścia wód podziemnych w Koninie. Model wykonany w programie Visual Modflow obejmował 5 warstw modelowych (3 warstwy wodonośne i 2 warstwy rozdzielające). Do kalibracji modelu początkowo zastosowano ręczną metodę "prób i błędów", uzyskując mało zadowalające wyniki zgodności położenia zwierciadła wody w punktach obserwacyjnych z wartościami obliczonymi. Następnie przystąpiono do przeprowadzenia automatycznej kalibracji parametrów z zastosowaniem pakietu optymalizacyjnego PEST. Zgodność pomiędzy wysokoscią zwierciadła wody obserwowaną a obliczoną za pomocą modelu matematycznego wzrosła do zadowalającego poziomu.

EN

The article presents the process of elabolatrion and calibration of an underground waters flow model in the area of the groundwaters intake in Konin. The model created in the Visual Modflow programme covered 5 model layers (3 water-bearing layers and 2 separating layers). Initially, the model was calibrated manually using the trial-and-error method what led to unsatisfactory results in the scope of conformity between the water-table location in observation points and the calculated values. In the next step, the automatic calibration of parameters with the use of the PEST optimisation package was carried out. The conformity between the water-table ІеvеІ observed and calculated with a mathematical model increased to a satisfactory degree.

12

Application of Newtonian nudging data assimilation method in hydrodynamic model of flood flow in the Lower Biebrza Basin

Mirosław-Świątek D.

Studia Geotechnica et Mechanica

|

2012

|

Vol. 34, nr 2

91-105

EN

The paper presents a 1D hydrodynamic flood flow model employing a data assimilation procedure based on Newtonian nudging. Data assimilation was used to determine correctly the upstream boundary condition defined as a discharge hydrograph. In the model developed, "nudging to individual observations" method was used. The data chosen for assimilation were water table levels recorded by a D-Diver automatic sensor installed in the river channel c. 1.5 km below a computational cross-section opening the analysed stretch of the river and the adjacent valley. This hydrological model of flood flow containing the data assimilation procedure is based on a one-dimensional Saint-Venant system of equations (dynamic wave model). The calculations were performed for the 2010 spring flood event at a 20-km stretch of the river and the floodplain in the upper part of the Lower Biebrza Basin. Modifying the boundary condition by using data assimilation has dramatically improved the accuracy of water table predictions during floods in the area of the Lower Biebrza Basin.

13

Contribution to one-dimensional model of a pulsating flow of gas in application to turbocharger inlet pipes

Olczyk A, Sobczak K.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

|

2008

|

nr 133

263--270

EN

The computational calculations employing the “x-t” model of a pulsating flow in the pipe and their experimental verification were described. The model, previously used for calculations of pressure signal variations in pneumatic transmission pipes, was adapted to the admission system of the turbocharger turbine. Appropriate boundary conditions were applied, using the experimental data provided by the measurements of unsteady flow parameters. The calculation results were compared to the experimental data showing a good agreement.

14

Model przepływu i wymiany ciepła w ożebrowanej współprądowej komorze spalania

Jesionek K., Goliński J.

Modelowanie Inżynierskie

|

2008

|

T. 4, nr 35

45-50

PL

Praca prezentuje inżynierską metodę przydatną w projektowaniu komory spalania dla układu siłowni cieplnej. Ciepło promieniowania gazów spalinowych obliczono wg metody McAdamsa. Temperaturę na powierzchni żeber oraz ilość ciepła przekazaną powietrzu chłodzącemu określono za pomocą tzw. "zmodyfikowanej funkcji Bessela". Zauważyć należy, że pod względem konstrukcyjnym (wytrzymałościowym) przedstawione rozwiązanie komory spalania jest łatwiejsze do wykonania niż dla obiegów o spalaniu wewnętrznym, w których ciśnienia czynników (powietrza i spalin) są dużo wyższe.

EN

This work presents an engineering method for cause in design of combustion chamber for an energy plant. The heat radiated by the combustion gases has been calculated according the McAdams method. The fin surface temperature and the amount of heat transmitted to the cooling air has been evaluated by use of the "modified Bessel function". A mention should be made that under structural strength respect the design solution for the combustion chamber which has been presented is easier to make than that for the internal heated cycles, in which the gas pressures (air and combustion gases) are much higher.

15

Koncepcja, realizacja numeryczna i właściwości zestawu programów służących do badania przepływu przez hydrauliczne maszyny wirowe

Zieliński A.

Górnictwo Odkrywkowe

|

2008

|

R. 49/2, nr 4-5

95-101

PL

Artykuł zawiera omówienie opracowanego przez autora zestawu sześciu programów komputerowych przeznaczonego do analizy i wspomagania projektowania palisad hydraulicznych maszyn wirowych. Realizowany jest dwuwymiarowy i quasi-trój-wymiarowy model przepływu. Wykorzystano metodą osobliwości oraz metodą krzywizny linii prądu.

EN

The paper contains the description of six computer programs developed by the present author for analysis and support in design of hydraulic rotodynamic machinery. Two-dimensional and quasi-three-dimensional models of flow were implemented. The singularity method and the streamline curvature method were applied.

16

Udziały objętościowe faz w przepływie trójfazowym powietrze - woda - olej w rurach pionowych

Nowak M., Troniewski L., Witczak S.

Inżynieria i Aparatura Chemiczna

|

2006

|

Nr 6s

168-169

EN

An attempt to connect the gas void fraction with flow patterns in three-phase air - water - oil flow was undertaken in the paper. A comparison of the measured and calculated gas void fractions for several models were described. The best agreement between the measured and calculated gas void fractions were obtained for strongly dispersed water - oil flow.

17

Stopnie zapełnienia faz wznoszącego przepływu mieszaniny wodno-olejowej w rurze pionowej

Troniewski L., Mydlarz-Gabryk K.

Inżynieria i Aparatura Chemiczna

|

2006

|

Nr 6s

241-242

EN

An attempt of adopting and examination of methods permitting the calculation of a very viscous phase fraction was undertaken in the paper. The methods applied are correct for up-ward adia-batic gas - liquid flow. A comparison of the oil volume fraction with the one resulting from mutual relation between streams of phases was executed. An influence of velocities of both phases on the oil fraction in flowing mixture was discussed.

18

Przepływ dwufazowy gaz - ciecz w kanale łukowym

Pietrzyk M., Witczak S.

Inżynieria i Aparatura Chemiczna

|

2006

|

Nr 6s

192-193

EN

The analysis and test results of hydrodynamics of two-phase gas - liquid flow in a pipe bend is presented in the paper. Types of flow patterns formed in a pipe bend and values of void fractions in phases were determined.

19

Weryfikacja i walidacja modelu na podstawie znaczników środowiskowych sześciofluorku siarki SF6 i trytu

Knez Janusz

Geologos

|

2006

|

Vol. 10

141--152

EN

Model was built of the exploitation region (RE) Kielce, as six layer hydrogeological numerical model with area 130,39 km2. Calculation was performed using Visual MODFLOV Pro ver. 3.1 The main task was to reconstruct the ground- water flow, determine the water resources budget and prepare transport model in an area of a local source of contamination (aromatic hydrocarbons). The regional model was divided by a regular mesh of 125 x 125 m with local more dense (25 x 25 m). The simulation was done in six layers: Quaternary porous aquifer (I and II model layers) and karstic-fissured Devonian aquifer (III, IV, V, VI model layers). An environmental tracer (SF6) and tritium was used to improve calibration of transport and flow models in the karstic-fissured aquifer. Simulated and measured 3H contents showed that improvement of conceptual model and calibration of flow and migration models are necessary for some parts of the aquifer. Residence time distributions serve for a better understanding of the groundwater system.

20

Investigations of phenomena accompanying in three phase gas-liquid-liquid flow

Pendyk B., Witczak S.

Turbulence : international journal

|

2005

|

Vol. 11

259-261

EN

The paper presents investigations of phenomena accompanying the three-phase flow, in particular, visual observation of the flow patterns being formed, determination of the hold-up levels of particular phases and occurrence of phase inversion phenomenon hi the flow.