Yatin Suri¹, Sheikh Zahidul Islam^{1, *}, Mamdud Hossain¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 297-337, 2020, DOI:10.32604/fdmp.2020.08421

Abstract The distribution of proppant injected in hydraulic fractures significantly affects the fracture conductivity and well performance. The proppant transport in thin fracturing fluid used during hydraulic fracturing in the unconventional reservoirs is considerably different from fracturing fluids in the conventional reservoir due to the very low viscosity and quick deposition of the proppants. This paper presents the development of a threedimensional Computational Fluid Dynamics (CFD) modelling technique for the prediction of proppant-fluid multiphase flow in hydraulic fractures. The proposed model also simulates the fluid leak-off behaviour from the fracture wall. The Euler-Granular and CFD-Discrete Element Method (CFD-DEM) multiphase modelling approach… More >

Shicheng He¹, Juhui Qiu¹, Wanling Liu¹, Tieying Yin¹, Dechuan Zhang^2,*, Donghua Liao^3,4, Haijun Zhang⁵, Yuxia Yin⁵, Guixue Wang^1,*

Molecular & Cellular Biomechanics, Vol.17, No.2, pp. 63-74, 2020, DOI:10.32604/mcb.2020.08750

Abstract Computational fluid dynamics (CFD) has been widely used for studying intracranial aneurysm hemodynamics, while its use for guiding clinical strategy is still in development. In this study, CFD simulations helped inform treatment decision for a middle cerebral artery (MCA) aneurysm case was investigated. A patient with a 10.4 × 9.8 mm aneurysm attached with a small aneurysm at the edge of the trifurcation in the left MCA was included in this study. For removing the MCA aneurysm, two scenarios were considered: Plan-A involved clipping the small aneurysm and Plan-B involved clipping the whole aneurysm. A suitable treatment plan was decided… More >

Zhenxia Mu¹, Xiaofei Xue¹, Minrui Fu¹, Dawei Zhao¹, Bin Gao¹, Yu Chang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.3, pp. 929-945, 2019, DOI:10.32604/cmes.2019.07627

Abstract In this work, the hemodynamic effects of the type-A aortic dissection in different entry and covering entry tear positions were mainly studied. It provides a new method or idea in the field of the aortic dissection hemodynamics, and it is of profound significance to provide basic theoretical research on the development of aortic dissection in the aspect of clinical judgment. Two type-A aortic dissection models with different entry tear positions (Model 1: The entry tear was located at the entrance of the ascending aorta, Model 2: The entry tear was located at the starting position of the descending aorta) were… More >

E. A. Semma¹, M. El Ganaoui², V. Timchenko³, E. Leonardi³

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.3, pp. 191-202, 2006, DOI:10.3970/fdmp.2006.002.191

Abstract This paper deals with the investigation of thermovibrational convection induced by harmonic oscillations of the temperature boundary conditions related to the hot wall in a Bridgman-like (VB) geometrical configurations. Two different models of the VB configuration are considered (a simplified version referred to as "restricted" model and a more realistic and complete model with phase change allowed). The effects of temperature modulation are considered for both models and with regard to several possible initial (basic) states (stationary and oscillatory). In the restricted fluid cavity, we identify the existence of a critical frequency minimizing the flow intensity in the steady basic… More >

Mohammadali Sharzehee¹, Yuan Chang², Jiang-ping Song², Hai-Chao Han^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 16-17, 2019, DOI:10.32604/mcb.2019.07129

Abstract A myocardial bridge (MB), a congenital anomaly of the coronary artery, occurs when a segment of the epicardial coronary artery goes underneath the myocardium. MBs are often observed in the middle part of the left anterior descending (LAD) artery. MB squeezes the vessel wall periodically and induces hemodynamic abnormalities which are correlated with angina and myocardial ischemia. The level of hemodynamics disturbances induced by MB depends on the myocardial bridge length, the degree of myocardial contractility, thickness, and location [1]. Hypertrophic cardiomyopathy (HCM), characterized by abnormal thickening of the heart wall, is a leading cause of death in patients of… More >

Zhiguo Zhang^1,*, Chen Jiang²

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 83-84, 2019, DOI:10.32604/mcb.2019.05749

Abstract To quantitatively analyze the aerodynamic changes in patient's trachea after the resection operation of hyperplastic granulation tissue, computational fluid dynamic (CFD) method was utilized to perform the simulation. Firstly, three dimensional finite element model of the patient’s trachea before and after surgery were reconstructed based on CT images; secondly, the numerical simulation based on CFD method was performed to investigate the changes in aerodynamic changes in patient's trachea after excision. Results indicated that the dyspnea symptom was largely alleviated after the removal surgery, the abnormal morphology was obviously improved and the resistance of trachea was decreased significantly. Present research also… 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 >

Cheng Zhang^{1, *}, Mingge Wu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 459-469, 2019, DOI:10.32604/fdmp.2019.08477

Abstract A computational study of the stretching mechanism of a liquid bridge and the effect of the liquid properties on the DPN (dip-pen nanolithography) process is presented. The results show that the viscosity and contact angle can have an appreciable influence on these processes. The greater the viscosity, the harder the liquid bridge is to break, which allows more molecular transfer during the DPN spotting process. Besides, when the contact angle between the liquid and substrate is less than 60 degrees, the time required to stretch the bridge and break it grows with the contact angle. During the stretching process, the… More >

Zhiyuan Cheng^{1, 2, *}, Yulan Wang¹, Yingang Wang², Qiong Nie²

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 357-366, 2019, DOI:10.32604/fdmp.2019.07843

Abstract On the basis of harmonic mapping theory, a mobile grid technology is applied to computational fluid dynamics (CFD). Starting from the observation that standard fixed-grid techniques often fail in addressing problems with large deformations, we elaborate a new algorithm relying on the software COMSOL Multiphysics 5.3a to solve the coupling of the mobile grid equation and the governing differential equations for fluid flow. The motion of water in a water tank when the tank waggles is simulated. We demonstrate that this technology can be implemented without a significant increase in the computational cost with respect to standard numerical methods More >

B. Šarler¹

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.2, pp. 185-194, 2005, DOI:10.3970/cmes.2005.007.185

Abstract This paper explores the application of the mesh-free radial basis function collocation method for solution of heat transfer and fluid flow problems. The solution procedure is represented for a Poisson reformulated general transport equation in terms of a-symmetric, symmetric and modified (double consideration of the boundary nodes) collocation approaches. In continuation, specifics of a primitive variable solution procedure for the coupled mass, momentum, and energy transport representing the natural convection in an incompressible Newtonian Bussinesq fluid are elaborated. A comparison of different collocation strategies is performed based on the two dimensional De Vahl Davis steady natural convection benchmark with Prandtl… More >