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… 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 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 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 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 More >

Biao Wang^1,*, Yongjian Yang¹, Hesong Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 649-678, 2019, DOI:10.31614/cmes.2019.05671

Abstract To calculate the diffusion law of chaff cloud launched by aircraft, taking rectangular chaff as an example, the diffusion model of chaff cloud is established in this paper. Firstly, the coordinate systems of chaff are defined and the motion model of chaff is established. The motion model mainly includes chaff motion equation and rotation equation, which are obtained by combining the aerodynamic moment and aerodynamic damping. Then, the influence of multi-chaff aerodynamic interference on the movement of chaff is analyzed. Finally, considering the influence of overlap area between chaffs and chaff spacing on the aerodynamic More >

Junjie Chen^* , Baofang Liu, Longfei Yan, Deguang Xu

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-15, 2018, DOI:10.5098/hmt.11.2

Abstract The combustion and emissions characteristics of methane-air mixtures in high-temperature catalytic micro-combustors were studied numerically. Both the heterogeneous and homogeneous chemistry were modeled simultaneously using detailed reaction mechanisms in order to better understand the role of each pathway in determining the product distributions. Computational fluid dynamics simulations were performed at a variety of pressures, temperatures, compositions, and combustor dimensions to determine their effects on the combustion and emissions characteristics. Comparisons were made between the results obtained for a purely heterogeneous case, a purely homogeneous case, and a coupled homogeneousheterogeneous case. It was shown that homogeneous More >

Wenxin Wang^1,2, Dalin Tang², Boyan Mao¹, Bao Li¹, Xi Zhao³, Jian Liu⁴, Youjun Liu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 163-173, 2018, DOI:10.31614/cmes.2018.04219

Abstract Fractional flow reserve (FFR) is the gold standard to identify individual stenosis causing myocardial ischemia in catheter laboratory. The purpose of this study is to present a fast simulation method to estimate FFR value of a coronary artery, which can evaluate the performance of vascular stenosis, based on resistance boundary conditions. A patient-specific 3-dimensional (3D) model of the left coronary system with intermediate diameter stenosis was reconstructed based on the CTA images. The resistance boundary conditions used to simulate the coronary microcirculation were computed based on anatomical reconstruction of coronary 3D model. This study was More >

Xudong Liu¹, Yunhan Cai¹, Bing Jia², Shengzhang Wang^1,*, Guanghong Ding¹

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 215-228, 2018, DOI:10.31614/cmes.2018.04158

Abstract Our study evaluated the hemodynamic performance of an axial flow blood pump surgically implanted in idealized total cavopulmonary connection (TCPC) models. This blood pump was designed to augment pressure from the inferior vena cava (IVC) to the pulmonary circulation. Two Fontan procedures with single and bilateral superior vena cava (SVC) were compared to fit the mechanical supported TCPC physiologies. Computational fluid dynamics (CFD) analyses of two Pump-TCPC models were performed in the analyses. Pressure-flow characteristics, energy efficiency, fluid streamlines, hemolysis and thrombosis analyses were implemented. Numerical simulations indicate that the pump produces pressure generations of… More >

Guangliang Pan¹, Yu Chang^1,*, Mingrui Fu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 199-213, 2018, DOI:10.31614/cmes.2018.04080

Abstract Patients with extracorporeal membrane oxygenation still suffer from high rates of complication that linked to the flow field within the blood pump. So it is essential to optimise the geometry of the pump. The specification of shroud design is arguably the necessary design parameter in the centrifugal pump. However, the hemodynamic performances of the different shroud designs have not been studied extensively. In this study, ten different shroud designs were made and divided into two groups as the different covering locations (A: Covering the blade leading edge, B: Covering the blade trailing edge). In every… More >