Fayi Yan^*, He Lu, Shijie Feng

Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1493-1514, 2024, DOI:10.32604/fhmt.2024.055324 - 30 October 2024

Abstract Helically coiled tube-in-tube (HCTT) heat exchangers are widely applied to the process technology because of their compactness and higher heat transfer efficiency. HCTT heat exchangers play an important role in liquified natural gas (LNG) use and cold energy recovery. The heat transfer characteristics, pressure distribution, and degree of vaporization of LNG in HCTT heat exchangers are numerically investigated. By comparing the simulation results of the computational model with existing experimental results, the effectiveness of the computational model is verified. The numerical simulation results show the vapor volume fraction of the HCTT heat exchanger is related… More >

Xin Liu^1,*, Kai Yan², Bo Fang³, Xiaoyu Sun³, Daqiang Feng⁴, Li Yin⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.7, pp. 1539-1552, 2024, DOI:10.32604/fdmp.2024.047922 - 23 July 2024

Abstract In response to the complex characteristics of actual low-permeability tight reservoirs, this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs, considering complex boundary shapes. Utilizing radial basis function point interpolation, the method approximates shape functions for unknown functions within the nodal influence domain. The shape functions constructed by the aforementioned meshless interpolation method have δ-function properties, which facilitate the handling of essential aspects like the controlled bottom-hole flow pressure in horizontal wells. Moreover, the meshless method offers greater flexibility and freedom compared to grid cell discretization, making it simpler… More >

Lihui Ma^1,*, Zhuo Han¹, Wei Li¹, Guangfeng Qi¹, Ran Cheng², Yuanyuan Wang¹, Xiangran Mi³, Xiaohan Zhang¹, Yunfei Li¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1381-1392, 2024, DOI:10.32604/fdmp.2024.046405 - 27 June 2024

Abstract When a gas-liquid two-phase flow (GLTPF) enters a parallel separator through a T-junction, it generally splits unevenly. This phenomenon can seriously affect the operation efficiency and safety of the equipment located downstream. In order to investigate these aspects and, more specifically, the so-called bias phenomenon (all gas and liquid flowing to one pipe, while the other pipe is a liquid column that fluctuates up and down), laboratory experiments were carried out by using a T-junction connected to two parallel vertical pipes. Moreover, a GLTPF prediction model based on the principle of minimum potential energy was… More >

Dongwei Wang^1,*, Lijian Cao¹, Weidong Wang², Jiajun Hu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 1103-1122, 2024, DOI:10.32604/fdmp.2023.042654 - 07 June 2024

Abstract A self-priming pump is a centrifugal pump that has the ability to prime itself. Typically, its performance depends on the configuration of its reflux hole. In this study, the ANSYS FLUENT software is used to investigate the effects of three different radial positions of the reflux hole on gas-liquid two-phase distribution, pressure pulsation, and imp during self-priming. The research results indicate that: (1) The effective channel size for the reflux liquid to enter the volute varies depending on the location of the reflux hole. The effect of the impeller rotation on the reflux liquid becomes… More >

Ming Yan¹, Caijiang Lu^2,*, Pan Shi^1,*, Meiling Zhang³, Jiawei Zhang¹, Liang Wang¹

Frontiers in Heat and Mass Transfer, Vol.22, No.2, pp. 615-631, 2024, DOI:10.32604/fhmt.2024.048333 - 20 May 2024

Abstract In response to escalating challenges in energy conservation and emission reduction, this study delves into the complexities of heat transfer in two-phase flows and adjustments to combustion processes within coal-fired boilers. Utilizing a fusion of hybrid modeling and automation technologies, we develop soft measurement models for key combustion parameters, such as the net calorific value of coal, flue gas oxygen content, and fly ash carbon content, within the Distributed Control System (DCS). Validated with performance test data, these models exhibit controlled root mean square error (RMSE) and maximum absolute error (MAXE) values, both within the… More > Graphic Abstract

Yongwei Duan, Zhaopeng Zhu, Hui He^*, Gaoliang Xuan, Xuemeng Yu

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 349-364, 2024, DOI:10.32604/fdmp.2023.042659 - 14 December 2023

Abstract The gas-water two-phase flow occurring as a result of fracturing fluid flowback phenomena is known to impact significantly the productivity of shale gas well. In this work, this two-phase flow has been simulated in the framework of a hybrid approach partially relying on the embedded discrete fracture model (EDFM). This model assumes the region outside the stimulated reservoir volume (SRV) as a single-medium while the SRV region itself is described using a double-medium strategy which can account for the fluid exchange between the matrix and the micro-fractures. The shale gas adsorption, desorption, diffusion, gas slippage… More >

Jingjing Gao, Xingkai Zhang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 109-127, 2024, DOI:10.32604/fdmp.2023.030106 - 08 November 2023

Abstract A new approach and a new related distribution system are proposed to address the issue of uneven steam injection caused by the different suction capacities of the used wells during the application of steam “stimulation” methods for enhanced oil recovery. The new distribution system consists of a swirler, spiral dividing baffles, and critical flow nozzles. Numerical simulations are used to analyze the flow-field and degree of steam homogeneity obtained with such an approach. The results indicate that a higher inlet pressure leads to better results. Additionally, the internal flow field becomes more stable, and the More >

Amer A. Abdulrahman¹, Bashar J. Kadhim¹, Zainab Y. Shnain¹, Hassan Sh. Majidi², Asawer A. Alwaiti^1,*, Farooq Al-Sheikh¹, Adnan A. AbdulRazak¹, Mohammed Shorbaz¹, Mazin J. Shibeeb³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2579-2595, 2023, DOI:10.32604/fdmp.2023.027454 - 25 June 2023

Abstract The well-known frictional effect related to liquid-liquid two-phase flow in pipelines can be reduced using drag-reducing additives. In this study, such an effect has been investigated experimentally using a mixture of oil and water. Moreover, numerical simulations have been carried out using the COMSOL simulation software. The measurements were taken in a horizontal pipe with the length and diameter equal to 3 and 0.125 m, respectively. Moreover, Polyethylene oxide with 150 ppm was exploited to reduce the drag effect while considering different water-to-oil fractions (0.3, 0.4, 0.5, and 0.7) and a constant total flow velocity More >

Mingjing Lu^1,2,*, Zenglin Wang^1,3, Aishan Li¹, Liaoyuan Zhang¹, Bintao Zheng¹, Zilin Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1269-1281, 2023, DOI:10.32604/fdmp.2023.023188 - 30 November 2022

Abstract A mathematical model for the gas-water two-phase flow in tight gas reservoirs is elaborated. The model can account for the gas slip effect, stress sensitivity, and high-speed non-Darcy factors. The related equations are solved in the framework of a finite element method. The results are validated against those obtained by using the commercial software CMG (Computer Modeling Group software for advanced recovery process simulation). It is shown that the proposed method is reliable. It can capture the fracture rejection characteristics of tight gas reservoirs better than the CMG. A sensitivity analysis of various control factors More >

Xuanyu Dong^1,*, Jingyao Yang²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 175-185, 2023, DOI:10.32604/fdmp.2022.021345 - 02 August 2022

Abstract A new numerical model for low-permeability reservoirs is developed. The model incorporates the nonlinear characteristics of oil-water two-phase flows while taking into account the initiation pressure gradient. Related numerical solutions are obtained using a finite difference method. The correctness of the method is demonstrated using a two-dimensional inhomogeneous low permeability example. Then, the differences in the cumulative oil and water production are investigated for different starting water saturations. It is shown that when the initial water saturation grows, the water content of the block continues to rise and the cumulative oil production gradually decreases. More >