T. K. Sreelakshmi¹, Abraham Annamma¹, A. S. Chethan¹, M. Krishna Murthy², C. S. K. Raju^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 599-616, 2021, DOI:10.32604/cmes.2021.013077 - 21 January 2021

Abstract The current article discusses the heat transfer characteristics of ferromagnetic liquid over an elastic surface with the thermal radiation and non-Fourier heat flux. In most of the existing studies, the heat flux is considered as constant, but whereas we incorporated the non-Fourier flux to get the exact performance of the flow. Also, we excluded the PWT and PHF cases to control the boundary layer of the flow. The governing equations related to our contemplate are changed into non-linear ordinary differential equations (ODE’s) by utilizing appropriate similarity changes, which are at the point enlightened by Runge–Kutta… More >

Thabet Abdeljawad^1,2,3, Muhammad Bilal Riaz^4,5, Syed Tauseef Saeed^6,*, Nazish Iftikhar⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 821-841, 2021, DOI:10.32604/cmes.2021.012529 - 21 January 2021

Abstract The main focus of this study is to investigate the impact of heat generation/absorption with ramp velocity and ramp temperature on magnetohydrodynamic (MHD) time-dependent Maxwell fluid over an unbounded plate embedded in a permeable medium. Non-dimensional parameters along with Laplace transformation and inversion algorithms are used to find the solution of shear stress, energy, and velocity profile. Recently, new fractional differential operators are used to define ramped temperature and ramped velocity. The obtained analytical solutions are plotted for different values of emerging parameters. Fractional time derivatives are used to analyze the impact of fractional parameters… More >

Ramadan A. ZeinEldin^1,2, Christophe Chesneau^3,*, Farrukh Jamal⁴, Mohammed Elgarhy⁵, Abdullah M. Almarashi⁶, Sanaa Al-Marzouki⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 791-819, 2021, DOI:10.32604/cmes.2021.012169 - 21 January 2021

Abstract Understanding a phenomenon from observed data requires contextual and efficient statistical models. Such models are based on probability distributions having sufficiently flexible statistical properties to adapt to a maximum of situations. Modern examples include the distributions of the truncated Fréchet generated family. In this paper, we go even further by introducing a more general family, based on a truncated version of the generalized Fréchet distribution. This generalization involves a new shape parameter modulating to the extreme some central and dispersion parameters, as well as the skewness and weight of the tails. We also investigate the More >

Weidong Lei¹, Hai Zhou^1,*, Hongjun Li², Rui Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 577-597, 2021, DOI:10.32604/cmes.2021.011857 - 21 January 2021

Abstract In order to simulate the propagation process of subway vibration of parallel tunnels in semi-infinite rocks or soils, time domain boundary element method (TD-BEM) formulation for analyzing the dynamic response of twin-parallel circular tunnels in an elastic semi-infinite medium is developed in this paper. The time domain boundary integral equations of displacement and stress for the elastodynamic problem are presented based on Betti’s reciprocal work theorem, ignoring contributions from initial conditions and body forces. In the process of establishing time domain boundary integral equations, some virtual boundaries are constructed between finite boundaries and the free… More >

Mohamed Abd-Elbasseer^*, Hatem Kh Mohamed

Sound & Vibration, Vol.55, No.1, pp. 43-55, 2021, DOI:10.32604/sv.2021.09417 - 19 January 2021

Abstract This research presents a thorough evaluation of the reverberation room at Acoustics Laboratory in National Institute of Standards (NIS) according to the related international standards. The evaluation aims at examining the room performance and exploring its effectiveness in the frequency range from 125 Hz to 10000 Hz according to the international standard requirements. The room, which was designed and built several years ago, is an irregular rectangular shape free from diffusers. Its volume is about 158.84 m³, which meets the requirement of the ISO 354 standard L_max < 1.9V^1/3. Cut-off frequencies of one and one-third octave are… More >

Ali Safari Variani¹, Masoumeh Ghorbanide¹, Sajad Zare², Saeid Ahmadi^1,*, Zahra Hashemi³

Sound & Vibration, Vol.55, No.1, pp. 31-41, 2021, DOI:10.32604/sv.2021.08930 - 19 January 2021

Abstract Acoustic performance of dissipative silencer was evaluated to determine the effectiveness of perforated duct porosity and absorbent material density in reducing occupational noise exposure propagated from centrifugal fan. Design charts were applied to predict noise reduction and length of a dissipative silencer. Dissipative silencers with various punched duct porosity (14%, 30% and 40%) and sound absorbent density (80 Kg/m³, 120 Kg/m³, and 140 Kg/m³) were designed and fabricated. According to ISO9612 and ISO11820, noise level was measured before and after installing all nine test silencers at fixed workstations around the discharge side of a centrifugal fan in… More >

H. Heydarnia^1,*, I. A. Kiselev¹, M. M. Ermolaev², S. Nikolaev³

Sound & Vibration, Vol.55, No.1, pp. 19-30, 2021, DOI:10.32604/sv.2021.04410 - 19 January 2021

Abstract Studying the vibrational behavior of feed drive systems is important for enhancing the structural performance of computer numerical control (CNC) machines. The preload on the screw and nut position have a great influence on the vibration characteristics of the feed drive as two very important operational conditions. Rotational acceleration of the screw also affects the performance of the CNC feed drive when machining small parts. This paper investigates the influence of preload and nut position on the vibration characteristics of the feed drive system of a CNC metal cutting machine in order to be able More >

Saqlain Abbas^1,2,*, Fucai Li¹, Zulkarnain Abbas^3,4, Taufeeq Ur Rehman Abbasi⁵, Xiaotong Tu⁶, Riffat Asim Pasha⁷

Sound & Vibration, Vol.55, No.1, pp. 1-18, 2021, DOI:10.32604/sv.2021.013754 - 19 January 2021

Abstract Structural health monitoring (SHM) is recognized as an efficient tool to interpret the reliability of a wide variety of infrastructures. To identify the structural abnormality by utilizing the electromechanical coupling property of piezoelectric transducers, the electromechanical impedance (EMI) approach is preferred. However, in real-time SHM applications, the monitored structure is exposed to several varying environmental and operating conditions (EOCs). The previous study has recognized the temperature variations as one of the serious EOCs that affect the optimal performance of the damage inspection process. In this framework, an experimental setup is developed in current research to… More >

Abiola O. Ajayeoba^1,*, Adewoye A. Olanipekun², Wasiu A. Raheem³, Oluwaseun O. Ojo⁴, Ayowumi R. Soji–Adekunle⁴

Sound & Vibration, Vol.55, No.1, pp. 69-85, 2021, DOI:10.32604/sv.2021.011639 - 19 January 2021

Abstract Economic wood processing employs the use of industrial machines for cutting, shaping, milling, and sawing timber, thereby leading to the generation of high levels of noise. Published data from empirical studies have categorized noise as an environmental hazard of global significance. Furthermore, noise exposure limits for different industries and all the industrial machines available has not been formally established as it presently exists in developed nations around the world. Therefore, this study assessed the daily exposure of sawmills workers to noise in Southwestern Nigeria. Reconnaissance surveys were first carried out in Osun, Oyo, Ondo, Ekiti,… More >

Dipeshkumar R. Sonaviya^*, Bhaven N. Tandel

Sound & Vibration, Vol.55, No.1, pp. 57-68, 2021, DOI:10.32604/sv.2021.010715 - 19 January 2021

Abstract Road traffic noise pollution has been recognized as a serious issue which affects human health as well as affects urban regions. Noise maps are very beneficial to identify the impact of noise pollution. A noise mapping study performed to study the propagation of noise in tier-II city along with field measurements. The noise maps are developed using a computer simulation model (SoundPLAN essential 4.0 software). The noise prediction models like U.K’s CoRTN, Germany’s RLS-90, and their modified versions, which can be used for homogenous road traffic conditions, cannot be successfully applied in heterogeneous road traffic… More >