Bogusław Bożek¹, Lucjan Sapa^1,*, Katarzyna Tkacz-Śmiech², Marek Danielewski², Janusz Rybak²

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 777-803, 2022, DOI:10.32604/cmes.2022.017729 - 13 December 2021

Abstract Low-temperature nitriding of steel or iron can produce an expanded austenite phase, which is a solid solution of a large amount of nitrogen dissolved interstitially in fcc lattice. It is characteristic that the nitogen depth profiles in expanded austenite exhibit plateau-type shapes. Such behavior cannot be considered with a standard analytic solution for diffusion in a semi-infinite solid and a new approach is necessary. We formulate a model of interdiffusion in viscoelastic solid (Maxwell model) during the nitriding process. It combines the mass conservation and Vegard’s rule with the Darken bi-velocity method. The model is formulated More >

Reza Khademi Zahedi¹, Naif Alajlan², Hooman Khademi Zahedi³, Timon Rabczuk^2,*

CMC-Computers, Materials & Continua, Vol.70, No.3, pp. 4635-4655, 2022, DOI:10.32604/cmc.2022.017682 - 11 October 2021

Abstract The outstanding thermal, optical, electrical and mechanical properties of molybdenum disolphide (MoS₂) heterostructures make them exceptional candidates for an extensive area of applications. Nevertheless, despite considerable technological and academic interest, there is presently a few information regarding the mechanical properties of these novel two-dimensional (2D) materials in the presence of the defects. In this manuscript, we performed extensive molecular dynamics simulations on pre-cracked and pre-notched all-molybdenum disolphide (MoS₂) heterostructure systems using ReaxFF force field. Therefore, we study the influence of several central-crack lengths and notch diameters on the mechanical response of 2H phase, 1T phase and… More >

Muhammad Naveed^1,*, Dumitru Baleanu^2,3, Ali Raza⁴, Muhammad Rafiq⁵, Atif Hassan Soori¹

CMC-Computers, Materials & Continua, Vol.70, No.2, pp. 3415-3431, 2022, DOI:10.32604/cmc.2022.020112 - 27 September 2021

Abstract Through the study, the nonlinear delayed modelling has vital significance in the different field of allied sciences like computational biology, computational chemistry, computational physics, computational economics and many more. Polio is a contagious viral illness that in its most severe form causes nerve injury leading to paralysis, difficulty breathing and sometimes death. In recent years, developing regions like Asia, Africa and sub-continents facing a dreadful situation of poliovirus. That is the reason we focus on the treatment of the polio epidemic model with different delay strategies in this article. Polio delayed epidemic model is categorized More >

O. M. Oyewola^a,b,*, O. S. Ismail^b, J. O. Bosomo^b

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-5, 2021, DOI:10.5098/hmt.17.8

Abstract This paper investigates possible inherent modifications of the radiative heat source term due to the influence of turbulence in the thermal radiation field of a gas turbine combustor flame. Adapting a flame temperature of 2000[K], COMSOL Multiphysics software was utilized to numerically simulate the process, assuming a gray gas participating medium with absorption coefficient of 0.03[m^-1]. The analysis of the results for five (5) different radial cut sections of the simulated combustor chamber shows that turbulence-radiation interactions cause radiative heat losses from the flame, with the divergence of the radiative heat flux having a deviation factor More >

Loc Vu-Quoc^1,*, Yuhu Zhai² and Khai D. T. Ngo³

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1441-1486, 2021, DOI:10.32604/cmes.2021.016784 - 25 November 2021

Abstract The Generalized Falk Method (GFM) for coordinate transformation, together with two model-reduction strategies based on this method, are presented for efficient coupled field-circuit simulations. Each model-reduction strategy is based on a decision to retain specific linearly-independent vectors, called trial vectors, to construct a vector basis for coordinate transformation. The reduced-order models are guaranteed to be stable and passive since the GFM is a congruence transformation of originally symmetric positive definite systems. We also show that, unlike the Pad´e-via-Lanczos (PVL) method, the GFM does not generate unstable positive poles while reducing the order of circuit problems.… More >

Simon Martinez¹, Jürgen Lenz¹, Hans Schindler^1,2, Willi Wendler¹, Stefan Rues³, Karl Schweizerhof^1,*, Sophia Terebesi², Nikolaos Nikitas Giannakopoulos², Marc Schmitter²

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1259-1281, 2021, DOI:10.32604/cmes.2021.017422 - 25 November 2021

Abstract The occlusal design plays a decisive role in the fabrication of dental restorations. Dentists and dental technicians depend on mechanical simulations of mandibular movement that are as accurate as possible, in particular, to produce interference-free yet chewing-efficient dental restorations. For this, kinetic data must be available, i.e., movements and deformations under the influence of forces and stresses. In the present study, so-called functional data were collected from healthy volunteers to provide consistent information for proper kinetics. For the latter purpose, biting and chewing forces, electrical muscle activity and jaw movements were registered synchronously, and individual More >

Weiwei Duan^*, Lingfeng Tang

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1143-1164, 2021, DOI:10.32604/fdmp.2021.016692 - 08 September 2021

Abstract Vertical infusion (self-emptying) bags used for Intravenous infusion are typically obtained by moulding a soft envelope of polypropylene. In normal conditions a continuous flow of liquid can be obtained with no need to use a pump. In the present study, the relationship between air pressure effects and the drug drip rate have been investigated experimentally and numerically. After determining relevant experimental data about the descending height of liquid level, the dropping speed and pressure, the ordinary least square method and MATLAB have been used to reconstruct the related variation and interrelation laws. Numerical simulations have More >

Ying Wang^*, Haoran Shi, Shibo Ren

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.3, pp. 967-983, 2021, DOI:10.32604/cmes.2021.015792 - 11 August 2021

Abstract The corrosion of reinforcement in the concrete will cause the effective cross-sectional area of reinforcement to be weakened and the performance of reinforcement to change and lead to the degradation of the bond behavior between reinforcement and concrete, which can seriously affect the mechanical properties of the structural elements. Therefore, it is of great practical significance to accurately simulate the corrosion morphology and the corrosion products of reinforcement. This paper improves the previous cellular automata models and establishes a new cellular automata model framework for simulating the random pitting corrosion process of reinforcement in concrete.… More >

Guanpeng Li¹, Lihui Sun², Zhaoyang Wang¹, Chunguo An¹, Chang Guo^3,*, Shen Cheng³, Ming Gao^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 989-1001, 2021, DOI:10.32604/fdmp.2021.016507 - 05 July 2021

Abstract Centrifugal pumps are widely used in engineering for a variety of applications. A known drawback of these devices is the high-level noise generated during operations, which can affect their stability and adversely influence the entire working environment. By combining the Powell vortex sound theory, numerical simulations and experimental measurements, this research explores the trends of variation and the corresponding underlying mechanisms for the flow-induced noise at various locations and under different operating conditions. It is shown that the total sound source intensity (TSSI) and total sound pressure level (TSPL) in the impeller, in the region More >

Shaomin Liang, Lu Liu, Shunying Ji^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 145-160, 2021, DOI:10.32604/cmes.2021.016403 - 28 June 2021

Abstract Based on the discrete element method and hydrostatics theory, an improved Archimedes principle is proposed to study the rules pertaining to resistance changes during the penetration process of an intruder into the particulate materials. The results illustrate the fact that the lateral contribution to the resistance is very small, while the tangential force of the lateral resistance originates from friction effects. Conversely, the resistance of particulate materials on the intruder mainly occurs at the bottom part of the intruding object. Correspondingly, the factors that determine the resistance of the bottom part of the intruding object… More >