M. Gh. Mohammed Kamil^1,*, M. S. Kassim¹, R. A. Mahmood^2,3, L. AZ Mahdi⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 985-998, 2022, DOI:10.32604/fdmp.2022.018938

Abstract This work investigates the steam condensation phenomena in an air-cooled condenser. The considered horizontal flattened tube has a 30 mm hydraulic diameter, and its length is a function of the steam quality with a limit value between 0.95 and 0.05. The mass flow rate ranges from 4 to 40 kg/m².s with a saturated temperature spanning an interval from 40°C to 80°C. A special approach has been implemented using the Engineering Equation Solver (EES) to solve a series of equations for the two-phase flow pattern and the related heat transfer coefficients. A wavy-stratified structure of the two-phase flow has been found when… More >

Shan Jin^1,2,3, Xiaohong Bai⁴, Wei Luo^1,2,3,*, Li Li⁴, Ruiquan Liao^1,2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1229-1242, 2020, DOI:10.32604/fdmp.2020.011051

Abstract With the increasing number of horizontal wells with low pressure, low yield, and water production, the phenomenon of water and liquid accumulation in gas wells is becoming progressively more serious. In order to fix these issues, it is necessary to improve existing drainage and gas recovery technologies, increase the fluid carrying capacity of these wells, and ensure that the bottom-hole airflow has enough energy to transport the liquid to the wellhead. Among the many techniques of drainage and gas recovery, the gas lift has recently become a popular method. In the present study, through the simulation of the entire horizontal… More >

Xiaoya Feng^{1, 2}, Wei Luo^{1, 2, *}, Yu Lei³, Yubin Su⁴, Zhigang Fang³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 339-358, 2020, DOI:10.32604/fdmp.2020.08564

Abstract Gas-liquid two-phase flow is ubiquitous in the process of oil and gas exploitation, gathering and transportation. Flow pattern, liquid holdup and pressure drop are important parameters in the process of gas-liquid two-phase flow, which are closely related to the smooth passage of the two-phase fluid in the pipe section. Although Mukherjee, Barnea and others have studied the conventional viscous gas-liquid two-phase flow for a long time at home and abroad, the overall experimental scope is not comprehensive enough and the early experimental conditions are limited. Therefore, there is still a lack of systematic experimental research and wellbore pressure for gas-liquid… More >

Zhihui Wang^1,2,3, Wei Luo^1,2,3,*, Ruiquan Liao^1,2,3, Xiangwei Xie⁴, Fuwei Han⁵, Hongying Wang⁶

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.5, pp. 583-595, 2019, DOI:10.32604/fdmp.2019.06847

Abstract Horizontal well production technology gradually occupies a dominant position in the petroleum field. With the rise in water production in the later stage of exploitation, slug flow phenomena will exist in horizontal, inclined and even vertical sections of gas wells. To grasp the flow law of slug flow and guide engineering practice, the flow law of slug flow at various inclination angles (30°~90°) is studied by means of the combination of laboratory experiments (including high frequency pressure data acquisition system) and finite element numerical simulation. The results reveal that because of the delay of pressure variation at the corresponding position… More >

Lijian Xu^1,2, Lekang Yin³, Fuyou Liang^1,2,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 71-72, 2019, DOI:10.32604/mcb.2019.05741

Abstract Recent studies have revealed that aortic valve diseases are associated with the increased incidence of the aortopathy development. However, the influence of aortic valve diseases on aortic hemodynamics remains unclear. The purpose of this study was therefore to investigate the hemodynamic differences in patients with and without aortic valve disease through patient-specific simulations performed on two aorta models (BAV with severe stenosis vs. normal tricuspid aortic valve (TAV)). Realistic geometries and boundary conditions were obtained from computed tomography angiography (CTA) and phase-contrast magnetic resonance imaging (PC-MRI) measurements, respectively. In addition, 4D-MRI were performed to validate the numerical methods used to… More >

Biyue Liu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.1, pp. 35-40, 2007, DOI:10.3970/icces.2007.001.035

Abstract It is well known that the Reynolds number has a significant effect on the blood flow in human arteries. We developed a three dimensional model with simplified geometry for a diseased right coronary artery segment to study the influence of the Reynolds number on the flow pattern in a stenotic coronary artery. Computations were carried out under physiological flow conditions to examine how the characteristics of the flow, such as the flow velocity and the pressure drop along the inner wall, change corresponding to the varying of the blood viscosity or to the varying of the mean inlet flow rate.… More >

C. K. Au¹

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.5, pp. 409-420, 2004, DOI:10.3970/cmes.2004.006.409

Abstract Tracking the flow fronts arising from a primary source in a bounded space with obstacles is a problem which often requires intensive computation. As the flow propagates through the obstacles, the flow pattern is complicated. This phenomenon is mainly due to the existence of the secondary sources which can be identified in the flow field by visibility. Comparing the flow fronts propagation and the wave equation reveals that the complexity is caused by the propagation phenomena: reflection, refraction, diffraction and interference. This paper investigates a geometric technique to combine these phenomena for computing flow fronts. More >

Jin Suo^*, John N. Oshinski^∗,†, D.P. Giddens^∗,‡

Molecular & Cellular Biomechanics, Vol.5, No.1, pp. 9-18, 2008, DOI:10.3970/mcb.2008.005.009

Abstract Atherosclerotic plaques in human coronary arteries are focal manifestations of systemic disease, and biomechanical factors have been hypothesized to contribute to plaque genesis and localization. We developed a computational fluid dynamics (CFD) model of the ascending aorta and proximal sections of the right and left coronary arteries of a normal human subject using computed tomography (CT) and magnetic resonance imaging (MRI) and determined the pulsatile flow field. Results demonstrate that flow patterns in the ascending aorta contribute to a pro-atherosclerotic flow environment, specifically through localization of low and oscillatory wall shear stress in the neighborhood of coronary orifices. Furthermore, these… More >

Jui-Ming Yang^*, Philip R. LeDuc^∗,†

Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 69-78, 2006, DOI:10.3970/mcb.2006.003.069

Abstract Inorganic and organic integrated systems detect, process, and respond to signals from solid media. Advances in fluidic systems have offered an alternative to traditional signaling methods through the development of aqueous signaling systems. Here, we show an experimentally simple mechanically governed fluidic system that creates three-dimensional molecular multiphase separation in a combination of discrete and continuous gradients analogous to digital and analog signals that can be used for controlled spatiotemporal cellular stimulation. We accomplish the pattern formation by fabricating a compartmentalized multi-level fluidics device where a network of capillaries converges into a main channel. Simultaneous control of the fluid streams… More >

Ridha Djebali^1,2, Bernard Pateyron², Mohamed El Ganaoui³

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.4, pp. 293-308, 2012, DOI:10.3970/cmes.2012.088.293

Abstract We present in this study a numerical investigation of unsteady two-dimensional natural convection of an electrically conducting fluid in a square cavity under an externally imposed magnetic field. A temperature gradient is applied between the two opposing side walls parallel to y-direction, while the floor and ceiling parallel to x-direction are adiabatic. The flow is characterized by the Rayleigh number Ra raged in 103-106, the Prandtl number Pr ranged in 0.01-10, the Hartman number Ha determined by the strength of the imposed magnetic field ranged in 0-100 and its tilting angle from x-axis ranging from 0 to 90 . The… More >