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Search results for: TWO-PHASE FLOW
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.10, b=0.14) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.10, b=0.14) and (C=6.20, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.70, b=0.32) and (C=3.30, b=0.40) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.10, b=0.14) and (C=3.30, b=0.40) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.70, b=0.32) and (C=6.20, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.80, b=0.25) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.70, b=0.32) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.70, b=0.32) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.80, b=0.25) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.10, b=0.14) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.4, b=0.26) and (C=5.3, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.7, b=0.32) and (C=4.4, b=0.42) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.1, b=0.14) and (C=5.3, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.0, b=0.11) and (C=4.4, b=0.42) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.7, b=0.32) and (C=5.3, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.0, b=0.11) and (C=5.3, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.8, b=0.25) and (C=5.3, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.5, b=0.37) and (C=4.4, b=0.42) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.1, b=0.14) and (C=4.4, b=0.42) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.8, b=0.25) and (C=4.4, b=0.42) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.5, b=0.37) and (C=5.3, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.4, b=0.26) and (C=4.4, b=0.42) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in-line. Four test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
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Jacek Tejchman prof. dr hab. inż.
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Dariusz Mikielewicz prof. dr hab. inż.
PeopleProfessor Dariusz Mikielewicz – born on February 6, 1967. in Gdansk. Here in 1974 he enrolled first to the Elementary School No. 17, and then in the Grammar School No. 5, named after Stefan Żeromski in Gdansk-Oliwa. After graduating from the Secondary School, with honors, in 1985 he successfully passed the entrance exams to the Faculty of Mechanical Engineering of Technical University of Gdansk, where he graduated with a very good...
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Data points of structures of R1233zd(E) flowing in a circular minichannel at low, medium and high values of saturation pressure
Open Research DataDatabase present structures of two-phase flow of R1233zd(E) in 3 mm vertical channel. Database contains datapoints which contain information of reduced pressure (ratio of saturation pressure and critical pressure), quality and mass velocity. 4 two phase structures are distinguished: bubbly flow, slug flow, intermittent flow and annular flow.
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Wioletta Gorczewska-Langner dr inż.
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Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels
PublicationAttention is focused on the issues of flow resistance and pressure drop of perspective refrigeration fluids during condensation in the two-phase flow in minichannels. The case of the flow through a cylindrical single channel of 2.3 mm inner diameter was carefully analyzed. Pressure drop tests have been performed in diabatic flow conditions. The effect of heat flux, mass flux, vapour quality and saturation temperature on the two-phase...
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Experimental investigations on adiabatic frictional pressure drops of R134a during flow in 5mm diameter channel
PublicationThe article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a at a saturation pressure of 5.5 bar corresponding to the saturation temperature of 19.4 °C. Study cases have been set for a mass flux varying from 100 to 500 kg/m2 s. The frictional pressure drop was characterized for the refrigerant R134a, for vapor qualities ranging from 0 to 1. Long-time thermal stability of test facility allowed to gather...
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Comparitive study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels
PublicationIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation...
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COMPARISON OF TWO MODELS OF CONDENSATION
PublicationIn the low-pressure part of steam turbine, the state path usually crosses the saturation line in penultimate stages. At least last two stages of this part of turbines operate in two –phase region. The liquid phase in this region in mainly created in the process of homogeneous and heterogeneous condensation. Several observations confirm however, that condensation often occurs earlier than it is predicted by theory i.e. before the...
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Experimental Investigations On The Momentum Pressure Drop During Flow Boiling Of R134a
PublicationThe article presents experimental investigations of the pressure drop during twophase flow. Experiments were performed for both adiabatic and heated flow of R134a. Obtained flow patterns were compared with the literature. Obtained data is used to validate momentum pressure drop predictions, a set of graphs showing comparisons, for a representative set of experimental conditions, of the two-phase frictional pressure gradients for...
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Non-adiabatic Effects in Pressure Drop Calculations in Flow Boiling and Flow Condensation in Minichannels
PublicationConsiderations presented in the paper relate both to the case of flow boiling and flow condensation in conventional channels as well as small diameter ones. Authors devoted all the possible attention that the modeling presented is applicable to the whole range of quality variation in both cases of condensation and boiling. The form of two-phase flow multiplier, which is a major factor in modeling presented here, should be capable...
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PRESSURE DROP OF HFE7000 AND HFE7100 IN FLOW CONDENSATION IN MINICHANNELS WITH ACCOUNT OF NON-ADIABATIC EFFECTS
PublicationFlow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena involving the change of phase. There is a temptation to describe both these phenomena with one only correlation. From amongst the structures present in flow boiling and flow condensation at least the annular flow structure seems to be mostly appropriate to the common modeling. However, the shear stress acting between vapor phase and liquid...
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Determination of pressure drop in flow condensation of HFE7000 in minichannels with account of non-adiabatic effects
PublicationFlow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena involving the change of phase. There is a temptation to describe both these phenomena with one only correlation, however such method has yet to be suggested. From amongst the structures present in flow boiling and flow condensation at least the annular flow structure seems to be mostly appropriate to the common modeling. However, the shear...
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EXPERIMENTAL VERIFICATION OF THE METHOD OF FLOW BOILING AND FLOW CONDENSATION HEAT TRANSFER PREDICTION FOR SELECTED FLUIDS
PublicationIn the paper presented are the results of calculations using authors own model to predict heat transfer coefficient during flow boiling of different refrigerants. The experimental data from various research studies from literature were collected. Calculations were conducted for a full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in- house developed model....
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Investigation of Liquid–Gas Flow in a Horizontal Pipeline Using Gamma-Ray Technique and Modified Cross-Correlation
PublicationThis article presents the application of the radioisotope absorption method in the study of two-phase water–air flow in a horizontal pipe. The measurement principle and the test stand are briefly described. The main part of the article presents the signal analysis methods applied to data obtained from scintillation detectors. Because these signals are mostly stochastic waveforms, they were analyzed statistically using the cross-correlation...
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Simulations of air and water flow in a model dike during overflow experiments
PublicationFlow in flood dikes, earth dams, and embankments occurs in variably saturated conditions, with pores of the earth material filled partly with water and partly with air. In routine engineering analysis, the influence of pore air is neglected and the air pressure is assumed equal to atmospheric. In some circumstances, for example, during overtopping of the dike by water, the effect of pore air on water flow and stability of the structure...
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Application of gamma densitometry and statistical signal analysis to gas phase velocity measurements in pipeline hydrotransport
PublicationThe work presents selected methods of signal analysis used in the processing of data obtained from radiometric probes. The used data came from an exemplary study of a two-phase liquid-gas flow at the laboratory installation. In such rigs many possible transport types may be observed, i.e. slug, plug and bubble flow, and each of them gives different signal-to-noise ratio of recorded data. Therefore, available radiometric methods...
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Application of gamma densitometry and statistical signal analysis to gas phase velocity measurements in pipeline hydrotransport
PublicationThe work presents selected methods of signal analysis used in the processing of data obtained from radiometric probes. The used data came from an exemplary study of a two-phase liquid-gas flow at the laboratory installation. In such rigs many possible transport types may be observed, i.e. slug, plug and bubble flow, and each of them gives different signal-to-noise ratio of recorded data. Therefore, available radiometric methods...
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Prediction of flow boiling heat transfer coefficient for carbon dioxide in minichannels and conventional channels
PublicationIn the paper presented are the results of calculations using authors own model to predict heat transfer coefficient during flow boiling of carbon dioxide. The experimental data from various resea rches were collected. Calculations were conducted for a full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house model. The results show the importance of taking into...
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Influence of heterogeneous air entry pressure on large scale unsaturated flow in porous media
PublicationThe paper presents numerical simulations of water infiltration in unsaturated porous media containing coarse-textured inclusions embed- ded in fine-textured background material. The calculations are performed using the two-phase model for water and air flow and a simplified model known as the Richards equation. It is shown that the Richards equation cannot correctly describe flow in the presence of heterogeneities. How- ever, its...
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A semi-empirical model for flow boiling heat transfer with account of the reduced pressure effect
PublicationIn the present study the attention was focused on the influence of reduced pressure on the predictions of heat transfer during flow boiling at the extensive range of pressures. The results of calculations were to test the sensitivity of the in-house flow boiling model with respect to the selection of the appropriate two-phase flow multiplier, which is one of the distinctive elements of that model. For this purpose a few two-phase...
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Analysis and interpretation of radiometric signals in a liquid-gas bubble flow
PublicationThe article presents the analysis of signals from a radiometric system consisting of two scintillation probes and two gamma radiation sealed sources. Calculations and interpretation were carried out for the bubble flow of the water-air mixture in the horizontal pipeline. The analysis of the obtained signals was done in time and frequency domain. In the frequency domain, a range of usable frequencies was identified, which were associated...
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Prediction of flow boiling heat transfer data for R134a, R600a and R290 in minichannels
PublicationIn the paper presented is the analysis of the results of calculations using a model to predict flow boiling of refrigerants such as R134a, R600a and R290. The latter two fluids were not used in development of model semiempirical correction. For that reason the model was verified with present experimental data. The experimental research was conducted for a full range of quality variation and a relatively wide range of mass velocity....
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The effect of reduced pressure on carbon dioxide flow boiling heat transfer in minichannels
Publication. In the paper presented are the results of the study on the effect of reduced pressure on flow boiling heat transfer data in minichannels as well as conventional ones. That effect renders that most of heat transfer correlations fail to return appropriate results of predictions. Mostly they have been developed for the reduced pressures from the range 0.1-0.3. The special correction has been postulated to the in-house model of flow...
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Determination of dryout localization using a five-equation model of annular flow for boiling in minichannels
PublicationDetailed studies have suggested that the critical heat flux in the form of dryout in minichannels occurs when the combined effects of entrainment, deposition, and evaporation of the film make the film flow rate go gradually and smoothly to zero. Most approaches so far used the mass balance equation for the liquid film with appropriate formulations for the rate of deposition and entrainment respectively. It must be acknowledged...
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A simplified energy dissipation based model of heat transfer for post-dryout flow boiling
Publicationmodel for post dryout mist flow heat transfer is presented based on considerations of energy dissipation in the flow. The model is an extension of authors own model developed earlier for saturated and subcooled flow boiling. In the former version of the model the heat transfer coefficient for the liquid singlephase convection as a reference was used, due to the lack of the appropriate model for heat transfer coefficient for the...
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Experimental investigations on pressure drop during the condensation in flow of HFE7000 in vertical minichannel
PublicationIn the work presented in the paper authors focused attention on the issues of flow resistance and pressure drop during condensation in the flow. The case of the descending flow through a cylindrical single-channel of 2.3 mm inner diameter was carefully analyzed. In the course of investigations a new working fluid HFE 7000 has been scrutinised which has a strongly differing properties in comparison to the other fluids that are commonly...
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Evaluation of the structures size in the liquid-gas flow by gamma-ray absorption
PublicationThe rapid development of tomography methods particularly electrical, X and gamma rays allows for a wide range of the information about flow structure. However, all of such methods are quite complicated. At the same time much simpler systems as the measuring system of gamma rays absorption, allows to obtain a all key flow information which describe the two-phase flow. In the article the results of analyzes of radiometric signal...
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Signals features extraction in radioisotope liquid-gas flow measurements using wavelet analysis
PublicationKnowledge of the structure of a flow is significant for the proper conduct of a number of industrial processes. In this case, a description of a two-phase flow regimes is possible by use of the time-series analysis in time, frequency and state-space domain. In this article the Discrete Wavelet Transform (DWT) is applied for analysis of signals obtained for water-air flow using gamma ray absorption. The presented method was illustrated...