Liqiong Chen¹, Kui Zhao¹, Kai Zhang^1,*, Duo Xv¹, Hongxvan Hu², Guoguang Ma¹, Wenwen Zhan³

Energy Engineering, Vol.121, No.8, pp. 2143-2165, 2024, DOI:10.32604/ee.2024.049362

Abstract The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment. In this study, computational fluid dynamics (CFD) method was applied to investigate the diffusion law and hazard range of buried natural gas pipeline leakage in mountainous environment. Based on cloud chart, concentration at the monitoring site and hazard range of lower explosion limit (LEL) and upper explosion limit (UEL), the influences of leakage hole direction and shape, soil property, burial depth, obstacle type on the diffusion law… More >

Jie-Di Weng¹, Yong-Zheng Jiang^1,*, Long-Chao Chen¹, Xu Zhang¹, Guan-Yong Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2533-2557, 2024, DOI:10.32604/cmes.2024.051232

Abstract Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved boundaries is vital in aircraft design, ocean, and construction engineering. However, current methods such as Lattice Boltzmann (LBM) and the immersion boundary method based on solid ratio (IMB) have limitations in identifying custom curved boundaries. Meanwhile, IBM based on velocity correction (IBM-VC) suffers from inaccuracies and numerical instability. Therefore, this study introduces a high-accuracy curve boundary recognition method (IMB-CB), which identifies boundary nodes by moving the search box, and corrects the weighting function in LBM by calculating the solid ratio of the boundary nodes,… More > Graphic Abstract

Ivan Sboev^1,*, Tatyana Lyubimova^2,3, Konstantin Rybkin³, Michael Kuchinskiy^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1425-1439, 2024, DOI:10.32604/fdmp.2024.051341

Abstract The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis, extraction and separation. One of the most important mechanisms at play in such processes is the acoustic cavitation due to the non-uniform distribution of acoustic pressure in the chamber. Cavitation has a strong impact on the surface degradation mechanisms. In this work, a numerical calculation of the acoustic pressure distribution inside the reactor chamber was performed using COMSOL Multiphysics. The numerical results have revealed the dependence of the structure of the acoustic pressure field on the boundary conditions More > Graphic Abstract

Ivan Karpunin^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1219-1232, 2024, DOI:10.32604/fdmp.2024.051062

Abstract The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally studied. It is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel segments. The intensity and direction of these flows depend on the dimensionless oscillating frequency. In the region of studied frequencies, the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each segment. For a fixed frequency, an increase in the… More >

Ruijin Huo^1,2,3, Qingxiang Pei^1,2,3, Xiaohui Yuan^1,*, Yanming Xu³

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2053-2077, 2024, DOI:10.32604/cmes.2024.049185

Abstract In this paper, a generalized th-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering problems. The Burton-Miller method is employed to solve the problem of non-unique solutions that may be encountered in the external acoustic field, and the th-order discretization formulation of the boundary integral equation is derived. In addition, the computation of loop subdivision surfaces and the subdivision rules are introduced. In order to confirm the effectiveness of the algorithm, the computed results are contrasted and analyzed with the results under Monte More >

Mingjian Li, Ping Yang^*, Pengyang Zhao

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2019-2034, 2024, DOI:10.32604/cmes.2024.048334

Abstract The experimental results in previous studies have indicated that during the ductile fracture of pure metals, vacancies aggregate and form voids at grain boundaries. However, the physical mechanism underlying this phenomenon remains not fully understood. This study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal defects. This derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain energy. Subsequently, a finite element model is developed for examining more general scenarios of interaction between vacancies and grain boundaries. This model is first verified and More >

Hanumesh Vaidya¹, Fateh Mebarek-Oudina^2,*, K. V. Prasad¹, Rajashekhar Choudhari³, Neelufer Z. Basha¹, Sangeeta Kalal¹

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 65-78, 2024, DOI:10.32604/fhmt.2024.047879

Abstract This investigation aims to analyze the effects of heat transport characteristics in the unsteady flow of nanofluids over a moving plate caused by a moving slot factor. The BRS variable is utilized for the purpose of analyzing these characteristics. The process of mathematical computation involves converting the governing partial differential equations into ordinary differential equations that have suitable similarity components. The Keller-Box technique is employed to solve the ordinary differential equations (ODEs) and derive the corresponding mathematical outcomes. Figures and tables present the relationship between growth characteristics and various parameters such as temperature, velocity, skin More > Graphic Abstract

K. Jyothi¹, Abhishek Dasore^2,3,*, R. Ganapati⁴, Sk. Mohammad Shareef⁵, Ali J. Chamkha⁶, V. Raghavendra Prasad⁷

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 79-105, 2024, DOI:10.32604/fhmt.2024.046891

Abstract In the current research, a thorough examination unfolds concerning the attributes of magnetohydrodynamic (MHD) boundary layer flow and heat transfer inherent to nanoliquids derived from Sisko Al₂O₃-Eg and TiO₂-Eg compositions. Such nanoliquids are subjected to an extending surface. Consideration is duly given to slip boundary conditions, as well as the effects stemming from variable viscosity and variable thermal conductivity. The analytical approach applied involves the application of suitable similarity transformations. These conversions serve to transform the initial set of complex nonlinear partial differential equations into a more manageable assembly of ordinary differential equations. Through the utilization… More > Graphic Abstract

Dewi Puspitasari¹, Diah Kusuma Pratiwi¹, Pramadhony Amran², Kaprawi Sahim^1,*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 305-315, 2024, DOI:10.32604/fhmt.2023.041882

Abstract The natural convection from a vertical hot plate with radiation and constant flux is studied numerically to know the velocity and temperature distribution characteristics over a vertical hot plate. The governing equations of the natural convection in two-dimension are solved with the implicit finite difference method, whereas the discretized equations are solved with the iterative relaxation method. The results show that the velocity and the temperature increase along the vertical wall. The influence of the radiation parameter in the boundary layer is significant in increasing the velocity and temperature profiles. The velocity profiles increase with More >

Muthasim Fahmy^†, Zhifa Sun

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-14, 2011, DOI:10.5098/hmt.v2.4.3003

Abstract A gas-liquid solute transfer process initiated in a closed vessel can exhibit Rayleigh-Bénard-Marangoni (RBM) convection enhanced mass transfer. For short exposure times experimental and theoretical results demonstrate that for deep liquid systems prior to solute penetration across the depth of the fluid, the stability thresholds of the system decreases with time. For thin liquid layers at longer exposure times the mass transfer enhancement under RBM convection can be affected in two ways: (1) solute penetration to the bottom liquid-solid boundary causing a departure from a penetration type concentration profile; (2) solute penetration to the top… More >