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

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 of flow in the ascending… More >

Thanh Tien Bui^1,*, Yoshihisa Fujita², Susumu Nakata²

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.2, pp. 425-442, 2021, DOI:10.32604/cmes.2021.016766

Abstract In this paper, we propose a simplified approach of open boundary conditions for particle-based fluid simulations using the weakly compressible smoothed-particle hydrodynamics (SPH) method. In this scheme, the values of the inflow/outflow particles are calculated as fluid particles or imposed desired values to ensure the appropriate evolution of the flow field instead of using a renormalization process involving the fluid particles. We concentrate on handling the generation of new inflow particles using several simple approaches that contribute to the flow field stability. The advantages of the . -SPH scheme, specifically the particle shifting technique, were successfully applied to correct the… More >

M.J. Huntul^*

Computer Systems Science and Engineering, Vol.39, No.3, pp. 415-429, 2021, DOI:10.32604/csse.2021.017924

Abstract The aim of this paper is to find the time-dependent term numerically in a two-dimensional heat equation using initial and Neumann boundary conditions and nonlocal integrals as over-determination conditions. This is a very interesting and challenging nonlinear inverse coefficient problem with important applications in various fields ranging from radioactive decay, melting or cooling processes, electronic chips, acoustics and geophysics to medicine. Unique solvability theorems of these inverse problems are supplied. However, since the problems are still ill-posed (a small modification in the input data can lead to bigger impact on the ultimate result in the output solution) the solution needs… More >

Syed Tauseef Saeed¹, Muhammad Bilal Riaz^2,3, Dumitru Baleanu^4,5,7,*, Ali Akgül⁶, Syed Muhammad Husnine¹

Intelligent Automation & Soft Computing, Vol.28, No.2, pp. 547-559, 2021, DOI:10.32604/iasc.2021.015982

Abstract Convective flow is a self-sustained flow with the effect of the temperature gradient. The density is non-uniform due to the variation of temperature. The effect of the magnetic flux plays a major role in convective flow. The process of heat transfer is accompanied by mass transfer process; for instance condensation, evaporation and chemical process. Due to the applications of the heat and mass transfer combined effects in different field, the main aim of this paper is to do comprehensive analysis of heat and mass transfer of MHD unsteady second-grade fluid in the presence of time dependent generalized boundary conditions. The… More >

Yezhi Qin, Ying Wang, Zhikai Wang^*, Xiongliang Yao

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.3, pp. 1093-1123, 2021, DOI:10.32604/cmes.2021.012969

Abstract The shock wave of the underwater explosion can cause severe damage to the ship structure. The propagation characteristics of shock waves near the structure surface are complex, involving lots of complex phenomena such as reflection, transmission, diffraction, and cavitation. However, different structure surface boundaries have a significant effect on the propagation characteristics of pressure. This paper focuses on investigating the behavior of shock wave propagation and cavitation from underwater explosions near various structure surfaces. A coupled Runge–Kutta discontinuous Galerkin (RKDG) and finite element method (FEM) is utilized to solve the problem of the complex waves of fluids and structure dynamic… More >

Miaomiao Ren^*, Xiaobin Shu

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 979-991, 2020, DOI:10.32604/fdmp.2020.09563

Abstract A novel algorithm is proposed for the simulation of fluid-structure interaction problems. In particular, much attention is paid to natural phenomena such as debris flow. The fluid part (debris flow fluid) is simulated in the framework of the smoothed particle hydrodynamics (SPH) approach, while the solid part (downstream obstacles) is treated using the finite element method (FEM). Fluid-structure coupling is implemented through dynamic boundary conditions. In particular, the software “TensorFlow” and an algorithm based on Python are combined to conduct the required calculations. The simulation results show that the dynamics of viscous and non-viscous debris flows can be extremely different… More >

Ying Xu¹, Ping Guo², Wenxia Zhou^1,*

International Journal of Mental Health Promotion, Vol.21, No.1, pp. 31-44, 2019, DOI:10.32604/IJMHP.2019.010742

Abstract Work engagement is a crucial positive psychological construct related to mental health. However, current self-directed and boundaryless career trend brings unprecedented challenges for organizations to foster employee engagement using traditional means. From an integrative perspective of the engagement theory and the career boundaryless theory, we built a model to test the moderating effect of person-vocation fit and trust in supervisor on the relationship between future work self and work engagement. After conducting a two-wave study with a sample of 231 employees, we found that future work-self was positively related to work engagement; and both person-vocation fit and trust in supervisor… More >

Mohammad Arefi¹, Masoud Mohammadi¹, Ali Tabatabaeian¹, Timon Rabczuk^{2, *}

CMC-Computers, Materials & Continua, Vol.62, No.3, pp. 1001-1023, 2020, DOI:10.32604/cmc.2020.08052

Abstract This study focuses on vibration analysis of cylindrical pressure vessels constructed by functionally graded carbon nanotube reinforced composites (FG-CNTRC). The vessel is under internal pressure and surrounded by a Pasternak foundation. This investigation was founded based on two-dimensional elastic analysis and used Hamilton’s principle to drive the governing equations. The deformations and effectivemechanical properties of the reinforced structure were elicited from the first-order shear theory (FSDT) and rule of mixture, respectively. The main goal of this study is to show the effects of various design parameters such as boundary conditions, reinforcement distribution, foundation parameters, and aspect ratio on the free… More >

Yiqiang Li¹, Liang Ma², Zhiqiang Yang³, Xiaofei Guan⁴, Yufeng Nie¹, Zihao Yang^{1, 2}

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.1, pp. 1-24, 2018, DOI:10.3970/cmes.2018.115.001

Abstract This paper is devoted to the homogenization and statistical multiscale analysis of a transient heat conduction problem in random porous materials with a nonlinear radiation boundary condition. A novel statistical multiscale analysis method based on the two-scale asymptotic expansion is proposed. In the statistical multiscale formulations, a unified linear homogenization procedure is established and the second-order correctors are introduced for modeling the nonlinear radiative heat transfer in random perforations, which are our main contributions. Besides, a numerical algorithm based on the statistical multiscale method is given in details. Numerical results prove the accuracy and efficiency of our method for multiscale… More >

David E. Soine, Richard J. Jones, Jr., Julie M. Harvie, Troy J. Skousen, Tyler F. Schoenherr

Sound & Vibration, Vol.52, No.1, pp. 9-12, 2018, DOI:10.32604/sv.2018.03629

Abstract Qualification of products to their vibration and shock requirements in a laboratory setting consists of two basic steps. The first is the quantification of the product’s mechanical environment in the field. The second is the process of testing the product in the laboratory to ensure it is robust enough to survive the field environment. The latter part is the subject of the “Boundary Condition for Component Qualification” challenge problem. This paper describes the challenges in determining the appropriate boundary conditions and input stimulus required to qualify the product. This paper also describes the step sand analyses that were taken to… More >