Fithry Mohd Amir^*, Mohd Zamri Yusoff, Saiful Hasmady Abu Hassan

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-15, 2022, DOI:10.5098/hmt.18.27

Abstract Nanofluid film on a horizontal tube is investigated numerically on the circular and multi-faceted cylinder. The fluid flow characteristics, including film thickness, shear stress, and thermal performance, are observed and analyzed. Fluid film on the circular surface is typical in many engineering applications, but the study of nanofluid film on non-circular surface is deficient in literature. The study provides a numerical model of a multi-faceted cylinder to simulate the nanofluid film on the non-circular surfaces using a volume of fluid (VOF) method. The ratio of Brownian motion to thermophoretic diffusion, N_BT developed along the film thickness More >

Suraj Shembekar^*, Dhananjay Zodpe, Pramod Padole

Molecular & Cellular Biomechanics, Vol.19, No.4, pp. 165-175, 2022, DOI:10.32604/mcb.2022.021513 - 27 December 2022

Abstract Arteriovenous fistula (AVF) is the endorsed method of vascular access for hemodialysis in end-stage renal disease (ESRD). However, more than 60% of AVF fail to mature for hemodialysis. Intimal hyperplasia leads to stenosis is the primary cause of fistula failure. Wall shear stress (WSS) is one of the important parameters that enact a crucial role in building of intimal hyperplasia. The prime purpose of this research work is to investigate the effect of anastomosis angle on WSS, pressure drop, venous outflow rate and identify the optimal angle of anastomosis of AVF, so that it helps… More >

Qingzhuo Chi¹, Huimin Chen¹, Shiqi Yang¹, Lizhong Mu^1,*, Changjin Ji², Ying He¹, Yong Luan³

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.1, pp. 31-47, 2022, DOI:10.32604/cmes.2022.018286 - 24 January 2022

Abstract Cardiovascular computational fluid dynamics (CFD) based on patient-specific modeling is increasingly used to predict changes in hemodynamic parameters before or after surgery/interventional treatment for aortic dissection (AD). This study investigated the effects of flow boundary conditions (BCs) on patient-specific aortic hemodynamics. We compared the changes in hemodynamic parameters in a type A dissection model and normal aortic model under different BCs: inflow from the auxiliary and truncated structures at aortic valve, pressure control and Windkessel model outflow conditions, and steady and unsteady inflow conditions. The auxiliary entrance remarkably enhanced the physiological authenticity of numerical simulations… More >

Mohamad Shukri Zakaria^1,*, Haslina Abdullah², Azmi Nordin¹, Syazwati Ahmad Zaki¹

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 171-179, 2021, DOI:10.32604/fdmp.2021.010974 - 09 February 2021

Abstract This study deals with the interaction of blood flow with the wall aorta, i.e., the boundary of the main artery that transports blood in the human body. The problem is addressed in the framework of computational fluid dynamics complemented with (FSI), i.e., a fluid-structure interaction model. Two fundamental types of wall are considered, namely a flexible and a rigid boundary. The resulting hemodynamic flows are carefully compared in order to determine which boundary condition is more effective in reproducing reality. Special attention is paid to wall shear stress (WSS), a factor known for its ability More >

Biyue Liu^1,*, Dalin Tang²

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 25-26, 2019, DOI:10.32604/mcb.2019.06825

Abstract The blood flow and mass transport pattern of low-density lipoprotein (LDL) in a right coronary artery with two stenoses are studied. Computations were carried out under physiological conditions. Our results show a strong correlation between wall shear stress (WSS) and distribution patterns of LDL. More >

Yahui Zhang¹, Hui Wang^1,2, Zhouming Mai^1,2, Jianhang Du^1,2,3,*, Guifu Wu^1,2,3

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 85-86, 2019, DOI:10.32604/mcb.2019.05836

Abstract Enhanced external counter pulsation (EECP) is an effective therapy to provide beneficial assistance for the failing heart by reducing cardiac afterload and increasing blood flow perfusion noninvasively. The technique of EECP involves the use of the EECP device to inflate and deflate a series of compression cuffs wrapped around the patient’s calves, lower thighs, and upper thighs. As the result, the enhanced flow perfusion is derived from the device’s propelling blood from veins of lower body to arteries of upper body and increases the blood supply for the important organs and brain. In the ACCF/AHA… More >

Sihan Chen¹, Bao Li¹, Haisheng Yang¹, Jianhang Du², Xiaoling Li², Youjun Liu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 149-162, 2018, DOI:10.31614/cmes.2018.04133

Abstract Enhanced external counterpulsation (EECP) is able to treat myocardial ischemia, which is usually caused by coronary artery stenosis. However, the underlying mechanisms regarding why this technique is effective in treating myocardial ischemia remains unclear and there is no patient-specific counterpulsation mode for different rates of coronary artery stenosis in clinic. This study sought to investigate the hemodynamic effect of varied coronary artery stenosis rates when using EECP and the necessity of adopting targeted counterpulsation mode to consider different rates of coronary artery stenosis. Three 3-dimensional (3D) coronary models with different stenosis rates, including 55% (Model… More >

Yanxia Wang¹, Yu Wang², Siqi Li³, ur Rehman Aziz³, Shutian Liu¹, Kairong Qin^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 127-147, 2018, DOI:10.31614/cmes.2018.03985

Abstract Assessment of the magnitude and pattern of wall shear stress (WSS) in vivo is the prerequisite for studying the quantitative relationship between exercise-induced WSS and arterial endothelial function. In the previous studies, the calculation of the WSS modulated by exercise training was primarily based upon the rigid tube model, which did not take non-linear effects of vessel elastic deformation into consideration. In this study, with an elastic tube model, we estimated the effect of a bout of 30-minute acute cycling exercise on the WSS and the flow rate in the common carotid artery according to… More >

Yang Li¹, Xiuxian Liu², Zhiyong Li^2,*, Jiayi Tong¹, Yi Feng¹, Genshan Ma¹, Chengxing Shen³, Naifeng Liu¹

Molecular & Cellular Biomechanics, Vol.14, No.4, pp. 213-229, 2017, DOI:10.3970/mcb.2017.014.213

Abstract Coronary tortuosity is a common angiographic finding, but the hemodynamic significance of coronary tortuosity is largely unknown. The impact of coronary tortuosity on coronary pressure and wall shear stress is still unclear. We addressed this issue in the present experimental study. A distorted tube model connected to heart pumping machine was established to simulate the coronary circulation. The pressure of each point was measured with a coronary pressure guidewire. Influence of tortuosity angle and tortuosity number on local pressure was measured. Wall shear stress was calculated accordingly to the pressure of each point. Pressure distribution… More >

Zhen Liu¹, Yan Cai¹, Guo-Zhong Chen², Guang-Ming Lu, Zhi-Yong Li^1,3,*

Molecular & Cellular Biomechanics, Vol.14, No.1, pp. 19-31, 2017, DOI:10.3970/mcb.2017.014.019

Abstract Background: Intracranial aneurysm (IA) can be commonly found in the circle of Willis (CoW), and a higher morbidity of IA is found to be associated with a higher percentage of an incomplete CoW. Hemodynamic factors are believed to play an important role in aneurysm formation. However, how the anatomical variations in CoW lead to hemodynamic difference and what hemodynamic parameters play important roles in aneurysm formation have not been quantified and assessed. Methods and Results: Thirty patients were included and based one computed tomography angiography, they were divided into three groups (10 patients per group):… More >