Yuanliang Tang^{1, 2}, Lizhong Mu¹, Ying He^{1, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 281-296, 2020, DOI:10.32604/fdmp.2020.06760 - 21 April 2020

Abstract The aim of this study is to develop a model of fluid and heat transfer in a biological tissue taking into account the exact structure of the related microvascular network, and to analyze the influence of structural changes of such a network induced by diabetes. A cubic region representing local skin tissue is selected as the computational domain, which in turn includes two intravascular and extravascular sub-domains. To save computational resources, the capillary network is reduced to a 1D pipeline model and embedded into the extravascular region. On the basis of the immersed boundary method… More >

Ping Yu^{1, *}, Chuanhui Huang¹, Lei Liu¹, Huafeng Guo¹, Chengqiang Liu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 267-280, 2020, DOI:10.32604/fdmp.2020.06528 - 21 April 2020

Abstract To study the heat and mass transfer characteristics of alkali metals in a combined porous wick in high-temperature heat pipes, a three-dimensional (3-D) numerical model is constructed by using the finite volume method, Darcy’s theory, and the theory of local thermal equilibrium. The research finds that the pressure drop of fluids flowing through a combined porous wick exhibits an increasing trend with increasing flow velocity at the inlet and with decreasing permeability of the porous media; a combined porous wick of lower porosity and permeability and larger fluid velocity at the inlet is found to More >

Xiang Liu¹, Liangbo Sun², Mingzhen Wang^{3, 4}, Bin Li², Lisheng Liu^{1, 5, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 153-183, 2020, DOI:10.32604/cmes.2020.08716 - 01 April 2020

Abstract A vein model was established to simulate the periodic characteristics of blood flow and valve deformation in blood-induced valve cycles. Using an immersed finite element method which was modified by a ghost fluid technique, the interaction between the vein and blood was simulated. With an independent solid solver, the contact force between vein tissues was calculated using an adhesive contact method. A benchmark simulation of the normal valve cycle validated the proposed model for a healthy vein. Both the opening orifice and blood flow rate agreed with those in the physiology. Low blood shear stress… More >

Yadong Zhang^{1, *}, Jiye Zhang²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 105-120, 2020, DOI:10.32604/fdmp.2020.07959 - 01 February 2020

Abstract The object of research of this paper is the DSA380 high-speed pantograph. The near-field unsteady flow around the pantograph was investigated using large eddy simulation (LES) while the far-field aerodynamic noise was analysed in the frame of the Ffowcs Williams-Hawkings (FW-H) acoustic analogy. According to the results, the contact strip, base frame and knuckle are the main aerodynamic noise sources, with vortex shedding, flow separation and recombination around the pantograph being related key physical factors. The aerodynamic noise radiates outwards in the form of spherical waves when the distance of the noise receiving point is… More >

Zhiyuan Dai¹, Tian Li^{1, *}, Weihua Zhang¹, Jiye Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 31-40, 2020, DOI:10.32604/fdmp.2020.07661 - 01 February 2020

Abstract Pantograph is a critical component of the high-speed train. It collects power through contact with catenary, which significantly affects the running safety of the train. Pantograph with double collector strips is one common type. The aerodynamic performance of the collector strips may affect the current collection of the pantograph. In this study, the aerodynamic performance of the pantograph with double strips is investigated. The numerical results are consistent with the experimental ones. The error in the aerodynamic drag force of the pantograph between numerical and experimental results is less than 5%. Three different conditions of More >

Daobing Wang^{1, *}, Sergio Zlotnik^{2, *}, Pedro Díez², Hongkui Ge³, Fujian Zhou³, Bo Yu⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 703-720, 2020, DOI:10.32604/cmes.2020.08033 - 01 February 2020

Abstract The hydraulic fracturing is a nonlinear, fluid-solid coupling and transient problem, in most cases it is always time-consuming to simulate this process numerically. In recent years, although many numerical methods were proposed to settle this problem, most of them still require a large amount of computer resources. Thus it is a high demand to develop more effificient numerical approaches to achieve the real-time monitoring of the fracture geometry during the hydraulic fracturing treatment. In this study, a reduced order modeling technique namely Proper Generalized Decomposition (PGD), is applied to accelerate the simulations of the transient,… More >

Tian Li^{1, *}, Zhiyuan Dai¹, Weihua Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 555-570, 2020, DOI:10.32604/cmes.2020.08101 - 01 February 2020

Abstract Detached eddy simulation has been widely applied to simulate the flow around trains in recent years. The Reynolds-averaged Navier-Stokes (RANS) model for delayed detached eddy simulation (DDES) is an essential user input. The effect of the RANS model for DDES on the aerodynamic characteristics of a train in crosswinds is investigated in this study. Three different DDES models are used, based on the Spalart-Allmaras model (SA), the realizable k-ε model (RKE), and the shear stress transport k-ω model (SST). Results show that all DDES models can give relatively accurate predictions of pressure coefficient on almost all More >

Muhammad Shoaib Arif^{1, *}, Ali Raza¹, Muhammad Rafiq², Mairaj Bibi³, Javeria Nawaz Abbasi³, Amna Nazeer³, Umer Javed⁴

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 61-77, 2020, DOI:10.32604/cmc.2020.08595

Abstract We are presenting the numerical simulations for the stochastic computer virus propagation model in this manuscript. We are comparing the solutions of stochastic and deterministic computer virus models. Outcomes of a threshold number R₀ hold in stochastic computer virus model. If R₀ < 1 then in such a condition virus controlled in the computer population while R₀ > 1 shows virus rapidly spread in the computer population. Unfortunately, stochastic numerical techniques fail to cope with large step sizes of time. The suggested structure of the stochastic non-standard finite difference technique can never violate the dynamical properties. On More >

Fuyong Su^a,*, Rui Song^a , Peiwei Ni^a , Zhi Wen^b

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-5, 2019, DOI:10.5098/hmt.12.25

Abstract A mathematical model of the inverse heat transfer problem of blast furnace lining is established in this study. Following the identification of the boundary conditions of the model, the inverse problem via the conjugate gradient method was decomposed into three issues: the direct problem, the sensitivity problem, and the adjoint problem. The feasibility of the model was verified through two types of real inner wall boundary shape functions. The effects of the initial inner wall boundary shape function and the number of measuring points are also investigated. Results showed that the accuracy of the inverse More >

Qingxin Ba^a , Scott Egbert^b, Xuefang Li^a,* , Lin Cheng^a,**

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-9, 2019, DOI:10.5098/hmt.12.20

Abstract Precalciner performance is crucial to the production rate and lifespan of cement kiln systems. The gas-solid flow and pulverized coal combustion processes in an industrial precalciner were numerically modeled to understand the flow patterns and thermal processes in the system. The gas and meal flow rates and properties were measured on-site to determine the boundary conditions for the simulations and to validate the models. The upward swirl of the gas flow in the furnace helped disperse the particles and extend their duration in the precalciner. The O₂ and CO₂ concentration distributions indicated that the coal particles More >