Editorial

5 pages, 161 KiB

Open AccessEditorial

Latest Progress and Applications of Multiphase Flow and Heat Transfer

by Liangxing Li

Appl. Sci. 2024, 14(8), 3369; https://0-doi-org.brum.beds.ac.uk/10.3390/app14083369 - 17 Apr 2024

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Multiphase flow and heat transfer are critical in both traditional and emerging area of engineering research [...] Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

Research

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16 pages, 2072 KiB

Open AccessArticle

Research and Application of Steam Condensation Heat Transfer Model Containing Noncondensable Gas on a Wall Surface

by He Li, Xiaoming Yang, Chen Wang, Shang Shi, Rubing Ma and Yidan Yuan

Appl. Sci. 2023, 13(18), 10520; https://0-doi-org.brum.beds.ac.uk/10.3390/app131810520 - 21 Sep 2023

Cited by 1 | Viewed by 948

Abstract

Steam condensation plays an important role in various engineering processes due to its excellent heat transfer performance. However, condensation in the presence of noncondensable gas has attracted great attention in recent years since noncondensable gas will have a negative effect on condensation heat [...] Read more.

Steam condensation plays an important role in various engineering processes due to its excellent heat transfer performance. However, condensation in the presence of noncondensable gas has attracted great attention in recent years since noncondensable gas will have a negative effect on condensation heat transfer. The present study proposes a comprehensive model coupled with convective heat transfer, liquid film heat transfer and steam condensation for the heat transfer of condensation with noncondensable gas and uses it in the Program Integrated for Severe Accident Analysis (PISAA) for a nuclear power plant. The condensation heat transfer model has good universality, the calculation process is stable with less iteration and a fast convergence and it is verified and validated by comparing the simulation results of the PISAA and those from traditional containment analysis codes, as well the experiments from the Wisconsin condensation tests; then, a sensitivity analysis for the parameters of the heat transfer coefficient is performed. The validation results show that the average error of the condensation heat transfer coefficient is approximately 10%, and the maximum error does not exceed 30%. The deviation from the experimental data is limited in the acceptable range, which could fulfill the requirement for the analysis of containment accidents in nuclear power plants. Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

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13 pages, 3004 KiB

Open AccessArticle

Enhanced Heat Transfer Study of Spherical Heat Storage Based on Response Surface Methodology

by Liwei Lu, Rui Tian, Xuan Gong and Yuanxing Zhao

Appl. Sci. 2023, 13(15), 8595; https://0-doi-org.brum.beds.ac.uk/10.3390/app13158595 - 26 Jul 2023

Cited by 1 | Viewed by 643

Abstract

In this paper, the effect of melting characteristics of CuO/paraffin wax composite phase change material in a spherical heat storage unit in a constant temperature water bath is investigated. Experiments were conducted in three different water bath temperatures (65 °C, 70 °C, and [...] Read more.

In this paper, the effect of melting characteristics of CuO/paraffin wax composite phase change material in a spherical heat storage unit in a constant temperature water bath is investigated. Experiments were conducted in three different water bath temperatures (65 °C, 70 °C, and 75 °C). The inner surface of the sphere was fixed with two, four, and six pin-shaped fins 3 mm in diameter. The spheres were filled with different mass fractions of CuO nanoparticles/paraffin phase change materials. Experimental CCD was used to model and optimize the spherical thermal storage unit. Regression models were developed to predict the effects of various operational factors on the melting time of the composite PCM. The factors in the model included the number of pin fins in the spherical heat storage unit, the water bath temperature, and the content of added CuO nanoparticles in the PCM, and ANOVA was used to statistically validate the regression model. The results showed that the interaction between the water bath temperature and the number of pin fins had the most significant effect on the melting time. With the melting time of the phase change material as the optimized objective function, the optimized optimal working condition was six pin fins, a water bath temperature of 75 °C, and the addition of 5 wt% CuO nanoparticles/paraffin phase change material, and the actual melting time under this condition was 78.9 min, which was lower than the predicted value of 79.4 min, with an error of 0.63% between them. Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

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17 pages, 9085 KiB

Open AccessArticle

Machine Learning Techniques Applied to Identify the Two-Phase Flow Pattern in Porous Media Based on Signal Analysis

by Xiangyu Li, Liangxing Li, Wenjie Wang, Haoxiang Zhao and Jiayuan Zhao

Appl. Sci. 2022, 12(17), 8575; https://0-doi-org.brum.beds.ac.uk/10.3390/app12178575 - 27 Aug 2022

Cited by 2 | Viewed by 1113

Abstract

The development of flow pattern identification technology for gas–liquid two-phase flow in porous media is of great significance to engineering research and production. In this paper, a high accuracy identification method for two-phase flow pattern in porous media is proposed with Machine learning [...] Read more.

The development of flow pattern identification technology for gas–liquid two-phase flow in porous media is of great significance to engineering research and production. In this paper, a high accuracy identification method for two-phase flow pattern in porous media is proposed with Machine learning techniques. The gas–liquid two-phase flow patterns and corresponding differential pressure signals in porous beds with particle diameters of 1.5 mm, 3 mm, and 6 mm are obtained through visual experiments. Three time domain characteristic parameters (Mean, Standard deviation, and Range) are calculated by a statistical method, while the EMD energy spectrum of the signal is obtained by empirical mode decomposition. Based on these parameters, machine learning technology, including support vector machine (SVM) and BP neural network, are employed to identify the flow pattern. Four flow pattern identification models are trained based on SVM and BP neural network, with accuracies of 94.77%, 93.4%, 96.08%, and 91.5%. Furthermore, the three models with good performance are integrated by integrated learning technology. An integrated identification model of gas–liquid two-phase flow pattern in porous media with an overall accuracy of 98.04% is finally obtained. Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

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31 pages, 19572 KiB

Open AccessArticle

The Effect of Porous Media on Wave-Induced Sloshing in a Floating Tank

by Wen-Huai Tsao, Ying-Chuan Chen, Christopher E. Kees and Lance Manuel

Appl. Sci. 2022, 12(11), 5587; https://doi.org/10.3390/app12115587 - 31 May 2022

Cited by 6 | Viewed by 1151

Abstract

Placing porous media in a water tank can change the dynamic characteristics of the sloshing fluid. Its extra damping effect can mitigate sloshing and, thereby, protect the integrity of a liquefied natural gas tank. In addition, the out-of-phase sloshing force enables the water [...] Read more.

Placing porous media in a water tank can change the dynamic characteristics of the sloshing fluid. Its extra damping effect can mitigate sloshing and, thereby, protect the integrity of a liquefied natural gas tank. In addition, the out-of-phase sloshing force enables the water tank to serve as a dynamic vibration absorber for floating structures in the ocean environment. The influence of porous media on wave-induced sloshing fluid in a floating tank and the associated interaction with the substructure in the ambient wave field are the focus of this study. The numerical coupling algorithm includes the potential-based Eulerian–Lagrangian method for fluid simulation and the Newmark time-integration method for rigid-body dynamics. An equivalent mechanical model for the sloshing fluid in a rectangular tank subject to pitch motion is proposed and validated. In this approach, the degrees of freedom modeling of the sloshing fluid can be reduced so the numerical computation is fast and inexpensive. The results of the linear mechanical model and the nonlinear Eulerian–Lagrangian method are correlated. The dynamic interaction between the sloshing fluid and floating body is characterized. The effectiveness of the added porous media in controlling the vibration and mitigating the sloshing response is confirmed through frequency response analysis. Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

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15 pages, 3421 KiB

Open AccessArticle

Hydrodynamic Fingering Induced by Gel Film Formation in Miscible Fluid Systems: An Experimental and Mathematical Study

by Muhammad Nasir, Ryuhei Yamaguchi, Yun She, Anindityo Patmonoaji, Mohammad Azis Mahardika, Weicen Wang, Zijing Li, Shintaro Matsushita and Tetsuya Suekane

Appl. Sci. 2022, 12(10), 5043; https://0-doi-org.brum.beds.ac.uk/10.3390/app12105043 - 17 May 2022

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Abstract

Hydrodynamic fingering induced by gel formation shares common features with growing biofilms, bacterial colonies, and the instability of a confined chemical garden. Fluid displacement with gel formation is also essential in various engineering applications, including CO₂ leakage remediation from storage reservoirs and [...] Read more.

Hydrodynamic fingering induced by gel formation shares common features with growing biofilms, bacterial colonies, and the instability of a confined chemical garden. Fluid displacement with gel formation is also essential in various engineering applications, including CO₂ leakage remediation from storage reservoirs and enhanced oil recovery. We conducted Hele-Shaw cell displacement experiments for a miscible fluid system using skim milk and aqueous citric acid solution. This study aimed to investigate the effects of gel film formation on the fingering instability of a miscible fluid system and develop a mathematical model of the sequential growth of gel film formation at the fingertip. We found that the gel film formation thickens with time, resulting in instability at the interface. A distinctive fingering pattern, resembling tentacles, appears where miscibility is suppressed, and the growth of the finger is localized at the fingertip. The finger width remains constant with increasing flow rate, whereas the number of fingers increases linearly before the fingers merge. The gap width significantly limits the finger width. Finally, a mathematical model of sequential film thickness growth for a bubble-like fingertip structure was developed. This model is based upon the interplay between the diffusion of citric acid through the existing gel film formation and elongation of the fingertip. The model provides an understanding of the fundamental mechanism of the growth of the bubble-like fingertip. Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

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13 pages, 3370 KiB

Open AccessArticle

Application of Neural Network and Time-Domain Feature Extraction Techniques for Determining Volumetric Percentages and the Type of Two Phase Flow Regimes Independent of Scale Layer Thickness

by Abdullah K. Alanazi, Seyed Mehdi Alizadeh, Karina Shamilyevna Nurgalieva, Slavko Nesic, John William Grimaldo Guerrero, Hala M. Abo-Dief, Ehsan Eftekhari-Zadeh, Ehsan Nazemi and Igor M. Narozhnyy

Appl. Sci. 2022, 12(3), 1336; https://0-doi-org.brum.beds.ac.uk/10.3390/app12031336 - 27 Jan 2022

Cited by 44 | Viewed by 3542

Abstract

One of the factors that significantly affects the efficiency of oil and gas industry equipment is the scales formed in the pipelines. In this innovative, non-invasive system, the inclusion of a dual-energy gamma source and two sodium iodide detectors was investigated with the [...] Read more.

One of the factors that significantly affects the efficiency of oil and gas industry equipment is the scales formed in the pipelines. In this innovative, non-invasive system, the inclusion of a dual-energy gamma source and two sodium iodide detectors was investigated with the help of artificial intelligence to determine the flow pattern and volume percentage in a two-phase flow by considering the thickness of the scale in the tested pipeline. In the proposed structure, a dual-energy gamma source consisting of barium-133 and cesium-137 isotopes emit photons, one detector recorded transmitted photons and a second detector recorded the scattered photons. After simulating the mentioned structure using Monte Carlo N-Particle (MCNP) code, time characteristics named 4th order moment, kurtosis and skewness were extracted from the recorded data of both the transmission detector (TD) and scattering detector (SD). These characteristics were considered as inputs of the multilayer perceptron (MLP) neural network. Two neural networks that were able to determine volume percentages with high accuracy, as well as classify all flow regimes correctly, were trained. Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

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24 pages, 86585 KiB

Open AccessArticle

A Numerical Analysis of the Influence of Nozzle Geometric Structure on Spontaneous Steam Condensation and Irreversibility in the Steam Ejector Nozzle

by He Li, Xiaodong Wang, Hailong Huang, Jiuxin Ning and Jiyuan Tu

Appl. Sci. 2021, 11(24), 11954; https://0-doi-org.brum.beds.ac.uk/10.3390/app112411954 - 15 Dec 2021

Cited by 4 | Viewed by 2285

Abstract

The spontaneous condensation of wet steam often occurs in the steam ejector nozzle, this deteriorates the performance of the steam ejector. In this paper, we take changing the geometric parameters of the nozzle as the focus of our research and construct an internal [...] Read more.

The spontaneous condensation of wet steam often occurs in the steam ejector nozzle, this deteriorates the performance of the steam ejector. In this paper, we take changing the geometric parameters of the nozzle as the focus of our research and construct an internal connection between steam’s condensation behavior and the nozzle’s throat radius, the nozzle’s divergent section expansion angle, and the nozzle’s divergent section length. Our numerical simulation results indicate that an increase in the throat diameter and reduction of the divergent section’s expansion angle can inhibit steam condensation behavior, to a certain extent. In particular, the steam condensation behavior will disappear at a 0° expansion angle, but it is not affected by the change in the divergent section’s length. In addition, the irreversibility that is seen under different changes to the nozzle’s structure parameters was investigated and the results show that the entropy generation that is caused by a phase change accounts for a much higher proportion of the total entropy generation than heat transport and viscous dissipation do. This indicates that steam’s condensation behavior makes a large amount of irreversible energy, resulting in energy waste and reducing the performance of the nozzle. Therefore, this study can provide a theoretical reference for suppressing the spontaneous condensation behavior of steam by changing the nozzle’s geometry. Full article

(This article belongs to the Special Issue Flow and Heat Transfer Research in Multiphase Flow and Porous Media)

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