Chun Ye^1,2,3, Jingjing Gao^1,2,3, Zhihui Wang^1,2,3, Weibiao Zheng^1,2,3, Yibei Wang^2,4, Xingkai Zhang^1,2,3,*, Ming Liu⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 755-766, 2023, DOI:10.32604/fdmp.2022.021868

Abstract The response of an adjustable critical-flow Venturi nozzle is investigated through a set indoor experiments aimed to determine the related critical flow rate, critical pressure ratio, and discharge coefficient. The effect of a variation in the cone displacement and liquid content on the critical flow characteristics is examined in detail and it is shown that the former can be used to effectively adjust the critical flow rate. The critical pressure ratio of the considered nozzle is above 0.85, and the critical flow control deviation of the gas flow is within ±3%. Liquid flow can reduce the gas critical mass flow… More >

Bin Ji¹, Hao Xu¹, Jie Yu¹, Shasha Li¹, Jun Ma¹, Yuke Ji^2,*, Huijun Liu¹

CMC-Computers, Materials & Continua, Vol.74, No.1, pp. 1303-1318, 2023, DOI:10.32604/cmc.2023.032168

Abstract An exhaustive study has been conducted to investigate span-based models for the joint entity and relation extraction task. However, these models sample a large number of negative entities and negative relations during the model training, which are essential but result in grossly imbalanced data distributions and in turn cause suboptimal model performance. In order to address the above issues, we propose a two-phase paradigm for the span-based joint entity and relation extraction, which involves classifying the entities and relations in the first phase, and predicting the types of these entities and relations in the second phase. The two-phase paradigm enables… 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

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 >

Xiaowei Nie¹, Lihui Ma^2,*, Yiqiu Xu³, Dong Sun², Weibo Zheng², Liang Zhou², Xiaodong Wang², Xiaohan Zhang², Weijia Dong², Yunfei Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 37-50, 2023, DOI:10.32604/fdmp.2023.021118

Abstract An experimental study was conducted to investigate the properties of stratified regular or wavy two-phase flow in two parallel separators located after a manifold. A total of 103 experiments with various gas and liquid velocity combinations in three inlet pipes were conducted, including 77 groups of outlet pipe resistance symmetry and 26 groups of outlet pipe resistance asymmetry trials. The experimental results have revealed that when the gas-liquid flow rate is low, the degree of uneven splitting is high, and “extreme” conditions are attained. When the superficial gas velocity is greater than that established in the extreme case, the direction… More >

Yuhui Zhou^1,2,3,*, Shichang Ju⁴, Qijun Lyu⁴, Hongfei Chen⁴, Xuebiao Du⁴, Aiping Zheng⁴, Wenshun Chen⁴, Ning Li⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 245-259, 2023, DOI:10.32604/fdmp.2023.019971

Abstract It is known that the pore media characteristics of glutenite reservoirs are different from those of conventional sandstone reservoirs. Low reservoir permeability and naturally developed microfractures make water injection in this kind of reservoir very difficult. In this study, new exploitation methods are explored. Using a real glutenite reservoir as a basis, a three-dimensional fine geological model is elaborated. Then, combining the model with reservoir performance information, and through a historical fitting analysis, the saturation abundance distribution of remaining oil in the reservoir is determined. It is shown that, using this information, predictions can be made about whether the considered… More >

Zenglin Wang¹, Liaoyuan Zhang¹, Anhai Zhong², Ran Ding², Mingjing Lu^2,3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1795-1804, 2022, DOI:10.32604/fdmp.2022.020020

Abstract Due to the difficulties associated with preprocessing activities and poor grid convergence when simulating shale reservoirs in the context of traditional grid methods, in this study an innovative two-phase oil-water seepage model is elaborated. The modes is based on the radial basis meshless approach and is used to determine the pressure and water saturation in a sample reservoir. Two-dimensional examples demonstrate that, when compared to the finite difference method, the radial basis function method produces less errors and is more accurate in predicting daily oil production. The radial basis function and finite difference methods provide errors of 5.78 percent and… More >

Dehui Tong^1,2, Shunshun Qin^1,2,*, Quan Liu^1,2, Yuhan Li³, Jiewei Lin^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1667-1682, 2022, DOI:10.32604/fdmp.2022.019768

Abstract Avoiding cavitation inside the water jacket is one of the most important issues regarding the proper design of a diesel engine’s cylinder liner. Using CFD simulations conducted in the frame of a mixture multiphase approach, a moving grid technology and near-wall cavitation model, in the present study the factors and fluid-dynamic patterns that influence cavitation are investigated from both macroscopic and mesoscopic perspectives. Several factors are examined, namely: wall vibration, water jacket width, initial cavitation bubble radius, coolant temperature, and number of bubbles. The results show that reducing the cylinder liner vibration intensity can significantly weaken the cavitation. Similarly, increasing… More >

Qin Qian¹, Mingjing Lu^1,2,*, Feng Wang³, Aishan Li¹, Liaoyuan Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 1089-1097, 2022, DOI:10.32604/fdmp.2022.019837

Abstract A Smooth Particle Hydrodynamics (SPH) method is employed to simulate the two-phase flow of oil and water in a reservoir. It is shown that, in comparison to the classical finite difference approach, this method is more stable and effective at capturing the complex evolution of this category of two-phase flows. The influence of several smooth functions is explored and it is concluded that the Gaussian function is the best one. After 200 days, the block water cutoff for the Gaussian function is 0.3, whereas the other functions have a block water cutoff of 0.8. The effect of various injection ratios… More >

Zhaiyk Tokhtarov^1,*, Vitaly Perov², Vitaly Borisov³, Evgeny Tikhomirov⁴, Olga Grunina⁵, Nadezhda Kapustina^5,6, Elmira Cherkasova⁷, Natalya Suray⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 1015-1024, 2022, DOI:10.32604/fdmp.2022.019534

Abstract After conducting a critical survey of the different categories of existing heat exchangers, the results of several experiments about the behaviour of a two-phase current in an open channel are reported. The results confirm the complexity of the problems induced in heat exchangers by flow maldistribution, especially when two-phase flows are considered in multi-channel systems. It is shown that severe misalignment of heat exchangers can lead to a loss of economic performance of more than 25%. Improper distribution of fluid flow causes longer fluid coils to form, and the liquid cochlea can eventually occupy a large space, thereby reducing heat… More >

Oleg R. Kuzichkin^1,*, Muneam Hussein Ali², Ayad F. Alkaim³, Lis M. Yapanto⁴, Gabdrakhman H. Valiev⁵, L. S. Abdullah⁶, Mustafa M. Kadhim⁷

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 1039-1048, 2022, DOI:10.32604/fdmp.2022.019532

Abstract A systematic study of two-phase (water-air) currents in open channels (water-air) has been conducted by means of experiments and numerical simulations. A dedicated device has been designed and manufactured on purpose. The numerical simulations have been based on the solution of a system of mass, momentum and energy balance equations for a two-phase fluid. The effect of different influential parameters has been explored, namely, velocity and dimensions of the channel, surface pressure and tension. More >