The Experts below are selected from a list of 25734 Experts worldwide ranked by ideXlab platform
Lusheng Zhai - One of the best experts on this subject based on the ideXlab platform.
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prediction of pressure drop for segregated oil water flows in small Diameter Pipe using modified two fluid model
Experimental Thermal and Fluid Science, 2020Co-Authors: Lusheng Zhai, Hongxin Zhang, Ningde JinAbstract:Abstract Horizontal segregated oil-water two-phase flows are widely encountered in oil wells. The pressure drop is an important parameter to evaluate the productivity of the horizontal oil well. In this study, through introducing dynamic contact angle, we calculate the oil-water interface shape by solving Young-Laplace equation. The oil-water interface shapes and the wave characteristics are considered to modify the closure relations of the two-fluid model (TFM), and consequently the pressure drop of horizontal oil-water flows is predicted using the modified TFM. In addition, we predict the pressure drop of horizontal oil-water flows using the TFM with flat interface. Through comparing the prediction results of the pressure drop, it is found that the TFM modified with dynamic contact angle allows for higher accuracy in pressure drop prediction, and it is not dependent on the flow pattern discrimination.
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prediction of curved oil water interface in horizontal Pipes using modified model with dynamic contact angle
Chinese Journal of Chemical Engineering, 2020Co-Authors: Hongxin Zhang, Lusheng Zhai, Ruoyu Liu, Cong Yan, Ningde JinAbstract:Abstract In this study, interface shapes of horizontal oil-water two-phase flow are predicted by using Young-Laplace equation model and minimum energy model. Meanwhile, the interface shapes of horizontal oil-water two-phase flow in a 20 mm inner Diameter Pipe are measured by a novel conductance parallel-wire array probe (CPAP). It is found that, for flow conditions with low water holdup, there is a large deviation between the model-predicted interface shape and the experimentally measured one. Since the variation of Pipe wetting characteristics in the process of fluid flow can lead to the changes of the contact angle between the fluid and the Pipe wall, the models mentioned above are modified by considering dynamic contact angle. The results indicate that the interface shapes predicted by the modified models present a good consistence with the ones measured by CPAP.
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the nonlinear analysis of horizontal oil water two phase flow in a small Diameter Pipe
International Journal of Multiphase Flow, 2017Co-Authors: Lusheng Zhai, Panagiota Angeli, Ningde Jin, Dashi Zhou, Lei ZhuAbstract:Horizontal oil-water two-phase flows are frequently encountered in many industrial processes but the understanding of the dynamic behavior underlying the different flow patterns is still a challenge. In this study, we first conduct experiments of horizontal oil-water flows in a small Diameter Pipe, and collect the fluctuation signals from conductance probes. The multi-scale power-law correlations of the oil-water flow structures are investigated using detrended fluctuation analysis (DFA) based on the magnitude and sign decomposition of the raw signals. The analysis reveals the scaling behavior of different flow structures; five conductive flow patterns are indentified based on the magnitude and sign scaling exponents at different time scales. In addition, the transfer entropy (TE) in a state space is used to study the information transferring characteristics of the oil-water mixture flowing past a conductance cross-correlation velocity probe. The results of TE indicate that the transferring information depends on the flow conditions and can be used to show changes in the flow patterns.
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multivariate multiscale complex network analysis of vertical upward oil water two phase flow in a small Diameter Pipe
Scientific Reports, 2016Co-Authors: Yuxuan Yang, Lusheng Zhai, Weidong Dang, Jialiang YuAbstract:High water cut and low velocity vertical upward oil-water two-phase flow is a typical complex system with the features of multiscale, unstable and non-homogenous. We first measure local flow information by using distributed conductance sensor and then develop a multivariate multiscale complex network (MMCN) to reveal the dispersed oil-in-water local flow behavior. Specifically, we infer complex networks at different scales from multi-channel measurements for three typical vertical oil-in-water flow patterns. Then we characterize the generated multiscale complex networks in terms of network clustering measure. The results suggest that the clustering coefficient entropy from the MMCN not only allows indicating the oil-in-water flow pattern transition but also enables to probe the dynamical flow behavior governing the transitions of vertical oil-water two-phase flow.
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experimental flow pattern map slippage and time frequency representation of oil water two phase flow in horizontal small Diameter Pipes
International Journal of Multiphase Flow, 2015Co-Authors: Lusheng Zhai, Yanbo ZongAbstract:Abstract We detect the flow structures of a horizontal oil–water two-phase flow in a 20 mm inner-Diameter Pipe using 8-channels radial mini-conductance probes. In particular, we present an experimental flow pattern map that includes 218 flow conditions and compare this map to the flow pattern transitional boundaries predicted by published models. In addition, using the Adaptive Optimal Kernel Time–Frequency Representation, we analyze the conductance fluctuating signals and characterize the flow pattern in terms of the total energy and dominant frequency. Based on the liquid holdup measurements using the quickly closing valve technology combined with three parallel-wire capacitance probes, we investigate the slip effect between the oil and water phases under various flow conditions. The results show that the flow structures greatly affect the slippage, and the slip ratio is sensitive to flow pattern variations.
Ningde Jin - One of the best experts on this subject based on the ideXlab platform.
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prediction of pressure drop for segregated oil water flows in small Diameter Pipe using modified two fluid model
Experimental Thermal and Fluid Science, 2020Co-Authors: Lusheng Zhai, Hongxin Zhang, Ningde JinAbstract:Abstract Horizontal segregated oil-water two-phase flows are widely encountered in oil wells. The pressure drop is an important parameter to evaluate the productivity of the horizontal oil well. In this study, through introducing dynamic contact angle, we calculate the oil-water interface shape by solving Young-Laplace equation. The oil-water interface shapes and the wave characteristics are considered to modify the closure relations of the two-fluid model (TFM), and consequently the pressure drop of horizontal oil-water flows is predicted using the modified TFM. In addition, we predict the pressure drop of horizontal oil-water flows using the TFM with flat interface. Through comparing the prediction results of the pressure drop, it is found that the TFM modified with dynamic contact angle allows for higher accuracy in pressure drop prediction, and it is not dependent on the flow pattern discrimination.
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prediction of curved oil water interface in horizontal Pipes using modified model with dynamic contact angle
Chinese Journal of Chemical Engineering, 2020Co-Authors: Hongxin Zhang, Lusheng Zhai, Ruoyu Liu, Cong Yan, Ningde JinAbstract:Abstract In this study, interface shapes of horizontal oil-water two-phase flow are predicted by using Young-Laplace equation model and minimum energy model. Meanwhile, the interface shapes of horizontal oil-water two-phase flow in a 20 mm inner Diameter Pipe are measured by a novel conductance parallel-wire array probe (CPAP). It is found that, for flow conditions with low water holdup, there is a large deviation between the model-predicted interface shape and the experimentally measured one. Since the variation of Pipe wetting characteristics in the process of fluid flow can lead to the changes of the contact angle between the fluid and the Pipe wall, the models mentioned above are modified by considering dynamic contact angle. The results indicate that the interface shapes predicted by the modified models present a good consistence with the ones measured by CPAP.
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the nonlinear analysis of horizontal oil water two phase flow in a small Diameter Pipe
International Journal of Multiphase Flow, 2017Co-Authors: Lusheng Zhai, Panagiota Angeli, Ningde Jin, Dashi Zhou, Lei ZhuAbstract:Horizontal oil-water two-phase flows are frequently encountered in many industrial processes but the understanding of the dynamic behavior underlying the different flow patterns is still a challenge. In this study, we first conduct experiments of horizontal oil-water flows in a small Diameter Pipe, and collect the fluctuation signals from conductance probes. The multi-scale power-law correlations of the oil-water flow structures are investigated using detrended fluctuation analysis (DFA) based on the magnitude and sign decomposition of the raw signals. The analysis reveals the scaling behavior of different flow structures; five conductive flow patterns are indentified based on the magnitude and sign scaling exponents at different time scales. In addition, the transfer entropy (TE) in a state space is used to study the information transferring characteristics of the oil-water mixture flowing past a conductance cross-correlation velocity probe. The results of TE indicate that the transferring information depends on the flow conditions and can be used to show changes in the flow patterns.
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multivariate weighted complex network analysis for characterizing nonlinear dynamic behavior in two phase flow
Experimental Thermal and Fluid Science, 2015Co-Authors: Zhongke Gao, Pengcheng Fang, Meishuang Ding, Ningde JinAbstract:Abstract Charactering nonlinear dynamic behavior in gas–liquid two-phase flow is a contemporary and challenging problem of significant importance. We in this paper first systematically carry out gas–liquid two-phase flow experiments in a small Diameter Pipe for measuring local flow information from different flow patterns. Then, we propose a modality transition-based network for mapping the experimental multivariate measurements into a directed weighted complex network. In particular, we derive multivariate complex networks from different flow conditions and demonstrate that the generated networks corresponding to different flow patterns exhibit distinct topological structures. For each generated network, we exploit weighted clustering coefficient and closeness centrality to quantitatively probe the network topological properties associated with dynamic flow behavior. The results suggest that our multivariate complex network analysis allows quantitatively uncovering the transitions of distinct flow patterns and yields deep insights into the nonlinear dynamic behavior underlying gas–liquid flows.
Barry J. Azzopardi - One of the best experts on this subject based on the ideXlab platform.
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Structures in gas–liquid churn flow in a large Diameter vertical Pipe
International Journal of Multiphase Flow, 2016Co-Authors: S. Sharaf, Ezekiel O. Agunlejika, G. Peter Van Der Meulen, Barry J. AzzopardiAbstract:Gas–Liquid two phase co-current flow in a vertical riser with an internal Diameter of 127 mm was investigated in the churn flow pattern. This paper presents detailed experimental data obtained using a Wire Mesh Sensor. It shows that the most obvious features of the flow are huge waves travelling on the liquid film. Wisps, large tendrils of liquid and the product of incomplete atomisation, which had previously detected in smaller Diameter Pipes, have also been found in the larger Diameter Pipe employed here. The output of the Wire Mesh Sensor has been used to determine the overall void fraction. When examined within a drift flux framework, it shows a distribution coefficient of ∼1, in contrast to data for lower gas flow rates. Film thickness time series extracted from the Wire Mesh Sensor output have been examined and the trends of mean film thickness, that of the base film and the wave peaks are presented and discussed. The occurrence of wisps and their frequencies have been quantified.
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structures in gas liquid churn flow in a large Diameter vertical Pipe
International Journal of Multiphase Flow, 2016Co-Authors: S. Sharaf, Ezekiel O. Agunlejika, Peter G Van Der Meulen, Barry J. AzzopardiAbstract:Gas–Liquid two phase co-current flow in a vertical riser with an internal Diameter of 127 mm was investigated in the churn flow pattern. This paper presents detailed experimental data obtained using a Wire Mesh Sensor. It shows that the most obvious features of the flow are huge waves travelling on the liquid film. Wisps, large tendrils of liquid and the product of incomplete atomisation, which had previously detected in smaller Diameter Pipes, have also been found in the larger Diameter Pipe employed here. The output of the Wire Mesh Sensor has been used to determine the overall void fraction. When examined within a drift flux framework, it shows a distribution coefficient of ∼1, in contrast to data for lower gas flow rates. Film thickness time series extracted from the Wire Mesh Sensor output have been examined and the trends of mean film thickness, that of the base film and the wave peaks are presented and discussed. The occurrence of wisps and their frequencies have been quantified.
Lei Zhu - One of the best experts on this subject based on the ideXlab platform.
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the nonlinear analysis of horizontal oil water two phase flow in a small Diameter Pipe
International Journal of Multiphase Flow, 2017Co-Authors: Lusheng Zhai, Panagiota Angeli, Ningde Jin, Dashi Zhou, Lei ZhuAbstract:Horizontal oil-water two-phase flows are frequently encountered in many industrial processes but the understanding of the dynamic behavior underlying the different flow patterns is still a challenge. In this study, we first conduct experiments of horizontal oil-water flows in a small Diameter Pipe, and collect the fluctuation signals from conductance probes. The multi-scale power-law correlations of the oil-water flow structures are investigated using detrended fluctuation analysis (DFA) based on the magnitude and sign decomposition of the raw signals. The analysis reveals the scaling behavior of different flow structures; five conductive flow patterns are indentified based on the magnitude and sign scaling exponents at different time scales. In addition, the transfer entropy (TE) in a state space is used to study the information transferring characteristics of the oil-water mixture flowing past a conductance cross-correlation velocity probe. The results of TE indicate that the transferring information depends on the flow conditions and can be used to show changes in the flow patterns.
S. Sharaf - One of the best experts on this subject based on the ideXlab platform.
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Structures in gas–liquid churn flow in a large Diameter vertical Pipe
International Journal of Multiphase Flow, 2016Co-Authors: S. Sharaf, Ezekiel O. Agunlejika, G. Peter Van Der Meulen, Barry J. AzzopardiAbstract:Gas–Liquid two phase co-current flow in a vertical riser with an internal Diameter of 127 mm was investigated in the churn flow pattern. This paper presents detailed experimental data obtained using a Wire Mesh Sensor. It shows that the most obvious features of the flow are huge waves travelling on the liquid film. Wisps, large tendrils of liquid and the product of incomplete atomisation, which had previously detected in smaller Diameter Pipes, have also been found in the larger Diameter Pipe employed here. The output of the Wire Mesh Sensor has been used to determine the overall void fraction. When examined within a drift flux framework, it shows a distribution coefficient of ∼1, in contrast to data for lower gas flow rates. Film thickness time series extracted from the Wire Mesh Sensor output have been examined and the trends of mean film thickness, that of the base film and the wave peaks are presented and discussed. The occurrence of wisps and their frequencies have been quantified.
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structures in gas liquid churn flow in a large Diameter vertical Pipe
International Journal of Multiphase Flow, 2016Co-Authors: S. Sharaf, Ezekiel O. Agunlejika, Peter G Van Der Meulen, Barry J. AzzopardiAbstract:Gas–Liquid two phase co-current flow in a vertical riser with an internal Diameter of 127 mm was investigated in the churn flow pattern. This paper presents detailed experimental data obtained using a Wire Mesh Sensor. It shows that the most obvious features of the flow are huge waves travelling on the liquid film. Wisps, large tendrils of liquid and the product of incomplete atomisation, which had previously detected in smaller Diameter Pipes, have also been found in the larger Diameter Pipe employed here. The output of the Wire Mesh Sensor has been used to determine the overall void fraction. When examined within a drift flux framework, it shows a distribution coefficient of ∼1, in contrast to data for lower gas flow rates. Film thickness time series extracted from the Wire Mesh Sensor output have been examined and the trends of mean film thickness, that of the base film and the wave peaks are presented and discussed. The occurrence of wisps and their frequencies have been quantified.