Barbara Tomaszewska-Wach, M. Rząsa, B. Dobrowolski, O. Serediuk
Flow measurements using differential pressure meters are common in industrial applications. In such cases, the flow of gas is often accompanied by conditions that can lead to liquid condensation. As a consequence, flow measurements basically involve gas–liquid mixture metering. For this reason, errors occur in the metering equipment resulting from the variations in the characteristics of the continuous phase that is present in the flow. In addition, the existence of a dispersed phase leads to the development of flow disturbance and pressure pulsations. Therefore, new methods and tools are being sought to enable the measurements of gas–liquid mixture flows that will offer a suitable accuracy of measurement in the instances of flow interference in the form of a liquid phase. This paper reports the results of a study into the application of orifice plate meters for gas–liquid mixture flow metering. The analysis of the influence of the geometry of an orifice meter on the measurement of a two-phase mixture flow was carried out for this purpose. Experimental tests were carried out by application of a standard orifice and three slotted orifice meters with various designs. The experiments included the measurements of air flow containing small amounts of dispersed water in the form of droplets. The analysis also involved the level of differential pressure that is obtained as a result of applying orifice meters, and the level of the permanent pressure loss caused by the installation of an orifice plate. The results of the research were compared with the results obtained for the standard orifice.
{"title":"INFLUENCE OF THE ORIFICE SHAPE ON MASS FLOW MEASUREMENTS OF AIRWATER MIXTURE","authors":"Barbara Tomaszewska-Wach, M. Rząsa, B. Dobrowolski, O. Serediuk","doi":"10.2495/MPF190041","DOIUrl":"https://doi.org/10.2495/MPF190041","url":null,"abstract":"Flow measurements using differential pressure meters are common in industrial applications. In such cases, the flow of gas is often accompanied by conditions that can lead to liquid condensation. As a consequence, flow measurements basically involve gas–liquid mixture metering. For this reason, errors occur in the metering equipment resulting from the variations in the characteristics of the continuous phase that is present in the flow. In addition, the existence of a dispersed phase leads to the development of flow disturbance and pressure pulsations. Therefore, new methods and tools are being sought to enable the measurements of gas–liquid mixture flows that will offer a suitable accuracy of measurement in the instances of flow interference in the form of a liquid phase. This paper reports the results of a study into the application of orifice plate meters for gas–liquid mixture flow metering. The analysis of the influence of the geometry of an orifice meter on the measurement of a two-phase mixture flow was carried out for this purpose. Experimental tests were carried out by application of a standard orifice and three slotted orifice meters with various designs. The experiments included the measurements of air flow containing small amounts of dispersed water in the form of droplets. The analysis also involved the level of differential pressure that is obtained as a result of applying orifice meters, and the level of the permanent pressure loss caused by the installation of an orifice plate. The results of the research were compared with the results obtained for the standard orifice.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130609234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many industrial applications involve fluidization systems in which it is possible to distinguish solid particles acting as a separate phase. The fluid–particle drag forces are well known and have been widely described in the literature to account for the momentum transfer between the phases whereas the study of particle–particle interaction still has several challenges especially for dense flow regimes. In this work, a novel method for the measurement of the particle–particle drag force was developed, using a cantilever beam with four strain gauges. For validation purposes, fluid–particle drag was investigated, the measurement device was evaluated considering two systems, in the first case, a spherical object was exposed to an air flow in a vertical tube where different velocities were used and for the second one, the forces resulting from impinging jet flows on the sphere were considered. The results show good agreement with the theoretical values. The results show good agreement with the theoretical values. The average magnitude of drag force upon a larger spherical object immersed on a flow of small particles was measured under different streams conditions, for different impinging height, size, and density of the particles.
{"title":"DIRECT MEASUREMENT OF SOLID DRAG FORCE IN FLUIDPARTICLE FLOW","authors":"A. M. Gomez, M. Nikku, P. Jalali","doi":"10.2495/MPF190021","DOIUrl":"https://doi.org/10.2495/MPF190021","url":null,"abstract":"Many industrial applications involve fluidization systems in which it is possible to distinguish solid particles acting as a separate phase. The fluid–particle drag forces are well known and have been widely described in the literature to account for the momentum transfer between the phases whereas the study of particle–particle interaction still has several challenges especially for dense flow regimes. In this work, a novel method for the measurement of the particle–particle drag force was developed, using a cantilever beam with four strain gauges. For validation purposes, fluid–particle drag was investigated, the measurement device was evaluated considering two systems, in the first case, a spherical object was exposed to an air flow in a vertical tube where different velocities were used and for the second one, the forces resulting from impinging jet flows on the sphere were considered. The results show good agreement with the theoretical values. The results show good agreement with the theoretical values. The average magnitude of drag force upon a larger spherical object immersed on a flow of small particles was measured under different streams conditions, for different impinging height, size, and density of the particles.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122111466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Experiments of shock-accelerated microparticles show high drag coefficients when the particles are tracked from initial acceleration through the relaxation times. An eight-pulse particle tracking diagnostic measures individual particle positions, and a schlieren system measures shock location, with pressure transducers providing shock speed at the test section. These diagnostics give us detailed measurements of particle positions versus time for Mach 1.2, 1.3 and 1.4 experiments, allowing us to calculate accelerations and drag. Findings show that early-time drag is underestimated by current quasi-steady drag models due to several factors. The exact physical mechanisms causing the large drag are likely due to body pressure forces caused by the particle wake disturbing the carrier phase.
{"title":"DRAG OF SHOCK-ACCELERATED MICROPARTICLES","authors":"K. Prestridge","doi":"10.2495/MPF190011","DOIUrl":"https://doi.org/10.2495/MPF190011","url":null,"abstract":"Experiments of shock-accelerated microparticles show high drag coefficients when the particles are tracked from initial acceleration through the relaxation times. An eight-pulse particle tracking diagnostic measures individual particle positions, and a schlieren system measures shock location, with pressure transducers providing shock speed at the test section. These diagnostics give us detailed measurements of particle positions versus time for Mach 1.2, 1.3 and 1.4 experiments, allowing us to calculate accelerations and drag. Findings show that early-time drag is underestimated by current quasi-steady drag models due to several factors. The exact physical mechanisms causing the large drag are likely due to body pressure forces caused by the particle wake disturbing the carrier phase.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126165523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Andredaki, A. Georgoulas, Nicolas Miché, M. Marengo
An enhanced volume of fluid (VOF)-based numerical simulation framework that accounts for conjugate heat transfer between solid and two-phase flow regions and phase-change due to boiling/condensation, is utilised in order to investigate the effect of flow oscillation amplitude and frequency on the liquid film evaporation and instability formation in slug-plug flows within heated channels, in saturated flow boiling conditions. Various series of parametric numerical simulations are performed, for different values of flow oscillation amplitude and frequency for a variety of working fluids. For one of the working fluids two different channel diameters are also tested. The oscillations in each case are induced by applying an oscillating pressure boundary condition at the inlet of the channel, keeping the pressure constant at the outlet, after an initial period of constant pressure drop between the inlet and the outlet. Capillary ridges that are initiated at the liquid film, in the vicinity of the leading edge of the considered vapour slugs, are identified as a result of the imposed oscillations, which are translated in the form of capillary waves towards the rear end of the bubbles. It is shown that the formation frequency as well as the geometric characteristics of the generated ridges, are directly related to the corresponding frequency and amplitude of the induced flow oscillations. Furthermore, it is shown that in the initial stages of the bubble fate after the application of the oscillations liquid film evaporation is enhanced with the increase of the oscillation amplitude while it degrades as the frequency of the oscillation becomes higher. However, for large oscillation amplitudes and channel diameters, liquid jets penetrate into the elongated bubbles leading in a lot of cases to bubble break-up.
{"title":"NUMERICAL INVESTIGATION OF LIQUID FILM INSTABILITIES AND EVAPORATION IN CONFINED OSCILLATING SLUG-PLUG FLOWS","authors":"M. Andredaki, A. Georgoulas, Nicolas Miché, M. Marengo","doi":"10.2495/MPF190121","DOIUrl":"https://doi.org/10.2495/MPF190121","url":null,"abstract":"An enhanced volume of fluid (VOF)-based numerical simulation framework that accounts for conjugate heat transfer between solid and two-phase flow regions and phase-change due to boiling/condensation, is utilised in order to investigate the effect of flow oscillation amplitude and frequency on the liquid film evaporation and instability formation in slug-plug flows within heated channels, in saturated flow boiling conditions. Various series of parametric numerical simulations are performed, for different values of flow oscillation amplitude and frequency for a variety of working fluids. For one of the working fluids two different channel diameters are also tested. The oscillations in each case are induced by applying an oscillating pressure boundary condition at the inlet of the channel, keeping the pressure constant at the outlet, after an initial period of constant pressure drop between the inlet and the outlet. Capillary ridges that are initiated at the liquid film, in the vicinity of the leading edge of the considered vapour slugs, are identified as a result of the imposed oscillations, which are translated in the form of capillary waves towards the rear end of the bubbles. It is shown that the formation frequency as well as the geometric characteristics of the generated ridges, are directly related to the corresponding frequency and amplitude of the induced flow oscillations. Furthermore, it is shown that in the initial stages of the bubble fate after the application of the oscillations liquid film evaporation is enhanced with the increase of the oscillation amplitude while it degrades as the frequency of the oscillation becomes higher. However, for large oscillation amplitudes and channel diameters, liquid jets penetrate into the elongated bubbles leading in a lot of cases to bubble break-up.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"958 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127032808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Rivera, J. Muñoz-Cobo, C. Berna, José-Luis Cuadros, Alberto Escrivá
A flow pattern, which appears in many industrial applications, is annular two-phase flow. Its main characteristic is that the main portion of the liquid mass is located at the walls of the tube forming an annulus, while the gas phase flows through the annulus core dragging small liquid drops. These drops are largely produced by the interactions of the gas-phase flowing through the gas core with the peaks of the disturbance waves, which are produced in the liquid/gas interface. This paper describes a set of experiments performed at the Vertical Annular Film Flow facility, in the annular flow regime, with upward liquid and gas flows, at different flow conditions varying the liquid surface tension by adding small amounts of 1-butanol to the water. The main property of 1-butanol is that small amounts of this substance significantly change the surface tension while the viscosity remains practically unchanged. The set of experiments were carried out inside a vertical tube 44 mm inner diameter, and 4.5 m high, the annular flow was created by means of a porous material with known porosity coefficient. The experimental conditions range from 2000 to 3500 l/min for the gas volumetric flow rate, and from 4 to 10 l/min for the liquid volumetric flow rate at atmospheric conditions. Several experiments have been carried out on 1-butanol varying the water surface tension from 72 10 Nm , to 45 10 Nm , at intermediate surface tensions. To measure the height of the disturbance waves and the thickness of the film we use a conductance probe – the electrical signal collected in the receiver sensor depends on the thickness of the liquid film layer. Correlations for the amplitude of the disturbance waves, the film base thickness and other physical magnitudes have been obtained with a good value for the coefficient of determination and the root mean square error.
{"title":"EXPERIMENTAL STUDY OF THE INTERFACIAL WAVES PRODUCED IN UPWARD VERTICAL ANNULAR FLOWS WHEN VARYING THE LIQUID-PHASE SURFACE TENSION","authors":"Y. Rivera, J. Muñoz-Cobo, C. Berna, José-Luis Cuadros, Alberto Escrivá","doi":"10.2495/MPF190031","DOIUrl":"https://doi.org/10.2495/MPF190031","url":null,"abstract":"A flow pattern, which appears in many industrial applications, is annular two-phase flow. Its main characteristic is that the main portion of the liquid mass is located at the walls of the tube forming an annulus, while the gas phase flows through the annulus core dragging small liquid drops. These drops are largely produced by the interactions of the gas-phase flowing through the gas core with the peaks of the disturbance waves, which are produced in the liquid/gas interface. This paper describes a set of experiments performed at the Vertical Annular Film Flow facility, in the annular flow regime, with upward liquid and gas flows, at different flow conditions varying the liquid surface tension by adding small amounts of 1-butanol to the water. The main property of 1-butanol is that small amounts of this substance significantly change the surface tension while the viscosity remains practically unchanged. The set of experiments were carried out inside a vertical tube 44 mm inner diameter, and 4.5 m high, the annular flow was created by means of a porous material with known porosity coefficient. The experimental conditions range from 2000 to 3500 l/min for the gas volumetric flow rate, and from 4 to 10 l/min for the liquid volumetric flow rate at atmospheric conditions. Several experiments have been carried out on 1-butanol varying the water surface tension from 72 10 Nm , to 45 10 Nm , at intermediate surface tensions. To measure the height of the disturbance waves and the thickness of the film we use a conductance probe – the electrical signal collected in the receiver sensor depends on the thickness of the liquid film layer. Correlations for the amplitude of the disturbance waves, the film base thickness and other physical magnitudes have been obtained with a good value for the coefficient of determination and the root mean square error.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"458 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125851119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the change of pressure and void fraction of adiabatic air–water two-phase flow through orifices are experimentally investigated. Horizontal pipes with an internal diameter of 25.4 mm with multiple orifices with area ratios of 0.062, 0.14, 0.25 and 0.54 are considered. Both pressure and void fraction distributions upstream and downstream of the orifice are obtained for intermittent flow patterns and are compared with a straight pipe without the restriction for gas superficial velocity of 0.657 m/s and liquid superficial velocity of 0.523 m/s. The flow redistribution across the orifices is also recorded using a high-speed imaging camera at a frame rate of up to 3 kHz. The effect of the area ratio on the local pressure and void fraction upstream and downstream of the restriction is investigated. The results show that the fully developed void fraction upstream of the orifice increased with the increase in the pressure-drop across the orifice. Far from the orifice, the values of the average pressure gradient and the time average void fraction of the piping with orifices approached the fully developed values similar to the case of the straight pipe without restriction. The flow pattern changes across the orifice are found to significantly depend on the area ratio.
{"title":"EXPERIMENTAL INVESTIGATION OF PRESSURE AND VOID FRACTION CHANGES FOR TWO-PHASE FLOW THROUGH FLOW-RESTRICTING ORIFICES","authors":"Naief Almalki, W. Ahmed","doi":"10.2495/MPF190151","DOIUrl":"https://doi.org/10.2495/MPF190151","url":null,"abstract":"In this work, the change of pressure and void fraction of adiabatic air–water two-phase flow through orifices are experimentally investigated. Horizontal pipes with an internal diameter of 25.4 mm with multiple orifices with area ratios of 0.062, 0.14, 0.25 and 0.54 are considered. Both pressure and void fraction distributions upstream and downstream of the orifice are obtained for intermittent flow patterns and are compared with a straight pipe without the restriction for gas superficial velocity of 0.657 m/s and liquid superficial velocity of 0.523 m/s. The flow redistribution across the orifices is also recorded using a high-speed imaging camera at a frame rate of up to 3 kHz. The effect of the area ratio on the local pressure and void fraction upstream and downstream of the restriction is investigated. The results show that the fully developed void fraction upstream of the orifice increased with the increase in the pressure-drop across the orifice. Far from the orifice, the values of the average pressure gradient and the time average void fraction of the piping with orifices approached the fully developed values similar to the case of the straight pipe without restriction. The flow pattern changes across the orifice are found to significantly depend on the area ratio.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128862196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Kopun, S. Ucsnik, Dongsheng Zhang, P. Sampl, S. Jaeger, R. Tatschl
{"title":"HIGH TEMPERATURE ALUMINIUM PLATE COOLING BY WATER IMPINGEMENT: NUMERICAL SIMULATION WITH ADAPTED CFD WATER COOLING MODELS AND EXPERIMENTAL VALIDATION","authors":"R. Kopun, S. Ucsnik, Dongsheng Zhang, P. Sampl, S. Jaeger, R. Tatschl","doi":"10.2495/MPF190071","DOIUrl":"https://doi.org/10.2495/MPF190071","url":null,"abstract":"","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133059835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In connection with the assessment of underground structures, the question arises of the mechanical behavior of the different types of materials of the load-bearing structure exposed to the explosion and the location of its source. This means that the stresses induced by shock waves due to the explosion are in direct relation with the properties of the lining material and the location of the charge. There are a number of numerical methods that deal not only with the issue of shock waves propagation in a closed or semi-closed environment, but also nonlinear properties of the material can be described. In order to feed the numerical procedures with the relevant data, it is essential to carry out practical tests that are best in scale models, saving time and money. Recall that there are means to evaluate the actual behavior of air, structure and surrounding rocks from observation in scale models. This paper focuses on the description of concrete circular tubes simulating the tunnel in the scale of 1/20. The three-phase flow is reduced to two phases (air, structure), for simplicity. The charge is placed on the longitudinal axis and also eccentrically, for comparison. The numerical method is suggested for the completeness of the flow behavior in the multiphase medium. The overpressure exerted on the lining is monitored by sensors that are located directly above the source of the explosion, further on the distal parts of the structure and ultimately overpressure at the mouth of the tube is monitored by the so-called pencil sensor. The source of the explosion is the Semtex 1A explosive in both explosion locations.
{"title":"COMPARISON OF THE EFFECTS OF EXPLOSIONS INITIATED AT DIFFERENT LOCATIONS IN MULTIPHASE MEDIA: AIR AND STRUCTURE","authors":"P. Procházka","doi":"10.2495/MPF190051","DOIUrl":"https://doi.org/10.2495/MPF190051","url":null,"abstract":"In connection with the assessment of underground structures, the question arises of the mechanical behavior of the different types of materials of the load-bearing structure exposed to the explosion and the location of its source. This means that the stresses induced by shock waves due to the explosion are in direct relation with the properties of the lining material and the location of the charge. There are a number of numerical methods that deal not only with the issue of shock waves propagation in a closed or semi-closed environment, but also nonlinear properties of the material can be described. In order to feed the numerical procedures with the relevant data, it is essential to carry out practical tests that are best in scale models, saving time and money. Recall that there are means to evaluate the actual behavior of air, structure and surrounding rocks from observation in scale models. This paper focuses on the description of concrete circular tubes simulating the tunnel in the scale of 1/20. The three-phase flow is reduced to two phases (air, structure), for simplicity. The charge is placed on the longitudinal axis and also eccentrically, for comparison. The numerical method is suggested for the completeness of the flow behavior in the multiphase medium. The overpressure exerted on the lining is monitored by sensors that are located directly above the source of the explosion, further on the distal parts of the structure and ultimately overpressure at the mouth of the tube is monitored by the so-called pencil sensor. The source of the explosion is the Semtex 1A explosive in both explosion locations.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116399755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Expansion processes and near-field structures in the two-phase flow within an aerated-liquid jet injected into a quiescent environment were experimentally explored with the confocal x-ray fluorescence technique available at Argonne National Laboratory. Quantitative time-averaged liquid and gas density distributions within the aerated-liquid jet were spatially resolved simultaneously. For the present injection condition, the observation of a dome-shaped gas plume head and a high gas density gradient within a short distance from the nozzle exit clearly indicates that the initial gas expansion processes across the nozzle exit are highly similar to those within a typical under-expanded gaseous jet. With the assistance of compressible gas expansion near the nozzle exit, the liquid plume exhibits a plume width larger than that of the aerating gas plume, leading to a separation between liquid and gas plumes at the downstream location. Expansion of the gas plume creates a region of low gas density, followed by a region of gas density recovery in the near field. The low gas density region resembles the region with over-expanded gas in front of a Mach disk inside a typical under-expanded gaseous jet. The density variation within the low density region, however, is small, indicating a low level of over expansion and a weak Mach disk. The present analysis of Mach disk location within the discharged aerating gas plume shows that, while the location can be generally identified from gas density measurements, the use of correlations for location identification may be unreasonable, due to the lack of direct measurement data on characteristic pressures.
{"title":"EXPANSION PROCESSES AND STRUCTURES OF TWO-PHASE FLOWS IN AERATED-LIQUID JETS DISCHARGED INTO A QUIESCENT ENVIRONMENT","authors":"Kuo-Cheng Lin, A. Kastengren, C. Carter","doi":"10.2495/MPF190201","DOIUrl":"https://doi.org/10.2495/MPF190201","url":null,"abstract":"Expansion processes and near-field structures in the two-phase flow within an aerated-liquid jet injected into a quiescent environment were experimentally explored with the confocal x-ray fluorescence technique available at Argonne National Laboratory. Quantitative time-averaged liquid and gas density distributions within the aerated-liquid jet were spatially resolved simultaneously. For the present injection condition, the observation of a dome-shaped gas plume head and a high gas density gradient within a short distance from the nozzle exit clearly indicates that the initial gas expansion processes across the nozzle exit are highly similar to those within a typical under-expanded gaseous jet. With the assistance of compressible gas expansion near the nozzle exit, the liquid plume exhibits a plume width larger than that of the aerating gas plume, leading to a separation between liquid and gas plumes at the downstream location. Expansion of the gas plume creates a region of low gas density, followed by a region of gas density recovery in the near field. The low gas density region resembles the region with over-expanded gas in front of a Mach disk inside a typical under-expanded gaseous jet. The density variation within the low density region, however, is small, indicating a low level of over expansion and a weak Mach disk. The present analysis of Mach disk location within the discharged aerating gas plume shows that, while the location can be generally identified from gas density measurements, the use of correlations for location identification may be unreasonable, due to the lack of direct measurement data on characteristic pressures.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126598368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CITATION: Mare, E. & Woudberg, S. 2019. Geometric versus kinetic modelling approach for characterizing porous metal foams. Wit Transactions on Engineering Sciences, 123(12):191-202, doi:10.2495/MPF190181.
引用本文:Mare, E. & woodberg, S. 2019。表征多孔金属泡沫的几何与动力学建模方法。工程科学学报，23(12):991 - 992,doi:10.2495/MPF190181。
{"title":"GEOMETRIC VERSUS KINETIC MODELLING APPROACH FOR CHARACTERIZING POROUS METAL FOAMS","authors":"E. Maré, S. Woudberg","doi":"10.2495/MPF190181","DOIUrl":"https://doi.org/10.2495/MPF190181","url":null,"abstract":"CITATION: Mare, E. & Woudberg, S. 2019. Geometric versus kinetic modelling approach for characterizing porous metal foams. Wit Transactions on Engineering Sciences, 123(12):191-202, doi:10.2495/MPF190181.","PeriodicalId":399001,"journal":{"name":"Computational and Experimental Methods in Multiphase and Complex Flow X","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117074086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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