Lingtong Li¹, Zaiguo Fu^{1, *}, Benxiang Li², Qunzhi Zhu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 23-44, 2020, DOI:10.32604/cmes.2020.09299 - 19 June 2020

Abstract The earth to fluid pipe (ETFP) system has been widely applied to various energy engineering. The numerical model of the heat transfer process in the ETFP system with a shallow-buried horizontal or a deep-buried vertical U-shape pipe adopted in practical engineering was established and the model distinctions were pointed out. The comparison of the thermal performance between the two types of ETFP system under various schemes was conducted on the basis of numerical prediction. The results showed that the thermal parameters of the ETFP system with a shallow-buried horizontal pipe were influenced by the inlet… More >

Weitao Zhang^{1, 2}, Mengqi Liu³, Kaiyi Wang⁴, Fan Zhang², Lei Hou^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1247-1266, 2020, DOI:10.32604/cmes.2020.09297 - 28 May 2020

Abstract Accidents involving natural gas leakage and dispersion pose a significant threat to human life and property. This threat is especially relevant at the street intersection at which dense buildings, heavy traffic flow, and complex underground pipe networks meet. Scholars have conducted numerous studies on gas leakage and dispersion, but investigations of natural gas leakage and dispersion at the street intersection of a building group are not in-depth. In this paper, we presented a three-dimensional (3D) physical model based on the Computational Fluid Dynamic (CFD) methodology to study the natural gas leakage and dispersion at the… More >

Hui Lu, Xinyue Duan, Minghai Xu^*, Liang Gong, Bin Ding

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1193-1204, 2020, DOI:10.32604/cmes.2020.08989 - 28 May 2020

Abstract In micro-manufacturing, roughness is unavoidable due to the tolerance of micro-machining methods. Roughness in microchannel could have a significant influence on flow and heat transfer since the size of microchannel is very small. In our work, roughness is modeled as a superposition of waves. A simple Fourier series method is proposed to construct the rough surface. With this method, roughness is constructed on the bottom of the rectangular microchannel which has a hydraulic diameter of 0.5 mm. Two important parameters during roughness construction, triangulate size and correlation length are studied under the same relative roughness More >

Zishen Li¹, Xiangling Gao^{1, *}, Zicheng Tang²

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1105-1129, 2020, DOI:10.32604/cmes.2020.09047 - 28 May 2020

Abstract The numerical simulation for a new type of precast concrete barrier for viaducts is carried out systematically. To obtain an accurate representation of the damage state of the concrete barrier under the impact of a vehicle, a stochastic damage-plasticity model of the concrete is adopted in the finite element model. Meanwhile, a simplified mathematical model of the impact between vehicles and the concrete barrier was established and the input energy was converted to the impact load to facilitate the investigation of the safety performance of the concrete barriers. On this basis, a refined finite element More >

Shengyang Feng^1,2,3,*, Dongbo Xiong⁴, Guojie Chen⁵, Yu Cui¹, Puxin Chen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 651-663, 2020, DOI:10.32604/fdmp.2020.07981 - 25 May 2020

Abstract Convection and diffusion are the main factors affecting radon migration. In this paper, a coupled diffusion-convection radon migration model is presented taking into account turbulence effects. In particular, the migration of radon is simulated in the framework of the k-ε turbulence model. The model equations are solved in a complex 3D domain by the finite element method (FEM). Special attention is paid to the case study about radon migration in an abandoned air defense shelter (AADS). The results show that air convection in a confined space has a great influence on the radon migration and the More >

Qingyun Yan¹, You Li², Yuanhong Zhu³, Kui Cheng³, Xueli Huang³, Cong Qi³, Xuemin Ye^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 623-636, 2020, DOI:10.32604/fdmp.2020.09669 - 25 May 2020

Abstract A hot primary-air pipe system is the bridge connecting an air-preheater with a coal mill in power generation stations. The effective geometrical configuration of the pipe network greatly affects the air flow distribution and consequently influences the safe and economic operation of milling systems in power stations. In order to improve the properties of the air flow, in the present work the SIMPLEC method is used to simulate numerically the flow field for the original layout of the system. As a result, the internal mechanisms influencing the uneven pressure drop in each branch are explored More >

Lin Wang¹, Chunguo An², Nini Wang², Yaming Ping¹, Kun Wang¹, Ming Gao^1,*, Suoying He¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 585-600, 2020, DOI:10.32604/fdmp.2020.09611 - 25 May 2020

Abstract Numerical simulation are conducted to explore the characteristics of the axial inflow and related aerodynamic noise for a large-scale adjustable fan with the installation angle changing from −12° to 12°. In such a range the maximum static (gauge) pressure at the inlet changes from −2280 Pa to 382 Pa, and the minimum static pressure decreases from −3389 Pa to −8000 Pa. As for the axial intermediate flow surface, one low pressure zone is located at the junction of the suction surface and the hub, another is located at the suction surface close to the casing… More >

Jinyu Ren, Dezhi Xu, Jing Xu^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 561-572, 2020, DOI:10.32604/fdmp.2020.09791 - 25 May 2020

Abstract Submarine maneuverability has been analyzed by means of computational fluid dynamics (CFD). This approach provides an alternative, accurate, and cost-effective method for simulating actual flow. The numerical results show that the numerical simulation of the viscous flow related to a moving submarine based on the RANS equation with a relevant turbulence model can not only provide rich flow field details such as flow separation, but also accurately predict its hydrodynamic performance. The present study indicates that CFD can be used to forecast the submarine’s maneuverability in the initial design stage. The present results will be More >

Yongtong Li¹, Liang Gong^{1, *}, Hui Lu¹, Dexin Zhang¹, Bin Ding¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 895-912, 2020, DOI:10.32604/cmes.2020.09009 - 01 May 2020

Abstract In the present study, the thermal performance of metal foam heat sink was numerically investigated by adopting the local thermal non-equilibrium (LTNE) model and local thermal equilibrium (LTE) model. Temperature field distributions and temperature difference field distributions of solid and fluid phases were presented. Detailed thermal performance comparisons based on the LTE and LTNE models were evaluated by considering the effects of the relevant metal foam morphological and channel geometrical parameters. Results indicate that a distinct temperature difference exists between the solid and fluid phases when the LTNE effect is pronounced. The average Nusselt numbers… More >

Matthieu Ancellin^{1, *}, Laurent Brosset², Jean-Michel Ghidaglia¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 359-381, 2020, DOI:10.32604/fdmp.2020.08642 - 21 April 2020

Abstract Numerous models have been proposed in the literature to include phase change into numerical simulations of two-phase flows. This review paper presents the modeling options that have been taken in order to obtain a model for violent separated flows with application to sloshing wave impacts. A relaxation model based on linear non-equilibrium thermodynamics has been chosen to compute the rate of phase change. The integration in the system of partial differential equations is done through a non-conservative advection term. For each of these modelling choices, some alternative models from the literature are presented and discussed. More >