Xiaorui Cheng^1,2,*, Yimeng Jiang¹, Min Li¹, Shuyan Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1047-1061, 2020, DOI:10.32604/fdmp.2020.010695

Abstract The influence of the axial mount position of the guide vane on the pressure fluctuation in a nuclear pump (AP1000) is investigated. The characteristics of the three-dimensional flow inside the nuclear pump are analyzed by means of numerical simulation. Results indicate that when the axial relative distance between the guide vane and the pumping chamber is reduced, in conditions of “small flow,” the efficiency of the pump increases, the pressure inside the pumping chamber decreases, while the losses related to the guide vane grow. Under large flow conditions, as the efficiency of the pump decreases, the losses for the guide… More >

Juan Du^1,*, Peng Dong², Vijayan Sugumaran³

Intelligent Automation & Soft Computing, Vol.26, No.4, pp. 715-723, 2020, DOI:10.32604/iasc.2020.010105

Abstract A dynamic optimized production scheduling which takes into account demand fluctuation and uncertainty is very critical for the efficient performance of Prefabricated Component Supply Chain. Previous studies consider only the conditions in the production factory and develop corresponding models, ignoring the dynamic demand fluctuation that often occurs at the construction site and its impact on the entire lifecycle of prefabricated construction project. This paper proposes a dynamic flow shop scheduling model for prefabricated components production, which incorporates demand fluctuation such as the advance of due date, insertion of urgent component and order cancellation. An actual prefabrication construction project has been… More >

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

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 (IBM) strategy, fluid and heat… More >

Jiacheng Dai¹, Jiegang Mou^{1, *}, Tao Liu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 161-179, 2020, DOI:10.32604/fdmp.2020.06613

Abstract The automobile engine pump is an important part of the automobile cooling system, and has a direct influence on the engine performance. Based on the SST k-ω turbulence model, unsteady numerical simulation for an automobile engine pump with different tip clearances was carried out by Fluent. To study the flow field characteristics and pressure fluctuation, the characteristics of secondary flow distribution in volute are also analyzed. The result shows that the pressure fluctuation characteristics of the flow field show obvious periodic variation at different levels of tip clearances. The peak value of pressure fluctuation at each monitoring point is dependent… More >

Chacón-Hernández J¹, E Cerna-Chávez², Y Ochoa-Fuentes², A Hernández-Juárez², L Palacios-Bazaldúa², J Landeros-Flores²

Phyton-International Journal of Experimental Botany, Vol.85, pp. 236-245, 2016, DOI:10.32604/phyton.2016.85.236

Abstract Spatial and vertical distributions, and population !uctuations of Tetranychus urticae and its predator Phytoseiulus persimilis were determined in four varieties of rose (Royal, Samuray, Red Baiser and Keiro) under greenhouse conditions. Nine samples for the pest and 8 samples for the predator were obtained. From 20 September to 18 November 2013, T. urticae and P. persimilis presented an aggregated distribution pattern during most of the sampling dates. At the same time, P. persimilis did not change the vertical distribution of T. urticae. A synchronous behavior between both predator and prey was observed in the four study varieties, although only the… More >

Jinshan Lin^a*, Chunhong Dou^b, Qianqian Wang^a

Sound & Vibration, Vol.52, No.2, pp. 11-15, 2018, DOI:10.32604/sv.2018.03653

Abstract A method for gearbox fault diagnosis consists of feature extraction and fault identification. Many methods for feature extraction have been devised for exposing nature of vibration data of a defective gearbox. In addition, features extracted from gearbox vibration data are identified by various classifiers. However, existing literatures leave much to be desired in assessing performance of different combinatorial methods for gearbox fault diagnosis. To this end, this paper evaluated performance of several typical combinatorial methods for gearbox fault diagnosis by associating each of multifractal detrended fluctuation analysis (MFDFA), empirical mode decomposition (EMD) and wavelet transform (WT) with each of neural… More >

Hao Dong¹, Yufeng Nie^1,2, Zihao Yang¹, Yang Zhang¹, Yatao Wu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.5, pp. 395-419, 2016, DOI:10.3970/cmes.2016.111.395

Abstract In this paper, we discuss the numerical accuracy of asymptotic homogenization method (AHM) and multiscale finite element method (MsFEM) for periodic composite materials. Through numerical calculation of the model problems for four kinds of typical periodic composite materials, the main factors to determine the accuracy of first-order AHM and second-order AHM are found, and the physical interpretation of these factors is given. Furthermore, the way to recover multiscale solutions of first-order AHM and MsFEM is theoretically analyzed, and it is found that first-order AHM and MsFEM provide similar multiscale solutions under some assumptions. Finally, numerical experiments verify that MsFEM is… More >

S. Taschini¹, J. Müller², A. Greiner², M. Emmenegger¹, H. Baltes¹, J.G. Korvink²

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 31-44, 2000, DOI:10.3970/cmes.2000.001.031

Abstract We present three techniques to accurately model the thermomechanical response of microsystem components: a new, accurate and stable Kirchhoff-Love multi-layered plate model implemented as an Argyris finite element, a model for the amplitude fluctuations of vibrational modes in micro-mechanical structures within a gaseous environment, and the consistent refinement of a finite element mesh in order to maximize the computational accuracy for a given mesh size. We have implemented these techniques in our in-house MEMS finite element program and accompanying Monte Carlo simulator. We demonstrate our approach to dynamic modeling by computing the thermomechanical response of a CMOS AFM beam. More >

H. Azoui¹, D. Bahloul^1,*, N. Soltani²

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.2, pp. 87-105, 2018, DOI: 10.3970/fdmp.2018.01149

Abstract In this work we have performed a three-dimensional numerical investigation in order to find the optimal conditions for growing efficiently high quality sapphire crystals with good thermal properties. We have studied thermal instabilities near the melt-crystal interface and the convective heat transfer under the Czochralski (Cz) process. We performed 3-D CFD simulation in cylindrical coordinates and used the Fast Fourier Transform method to analyze the temperature fluctuations. We present a detailed investigation on the effects of the crystal rotation speed and the temperature distribution on thermal instabilities of sapphire melt under forced convection. Where the melt forced convection, the radiative… More >

Hayder A. Abdulbari ^1,2, Hassan D. Mahammed¹, Z. Hassan, Wafaa K. Mahmood³

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.2, pp. 86-101, 2016, DOI:10.3970/fdmp.2016.012.086

Abstract An experimental investigation was carried out to study the response of a turbulent pressure drop fluctuations to longitudinal groove riblets, involved two configurations being triangular and spaced triangular grooves with height 600, 800, 1000 μm and peak to peak spacing 1000 μm and 2000 μm respectively. Experiments were therefore performed at free stream velocity up to 0.44 m/sec, which were corresponding to Reynolds number (Re) 53000. The development of the obtained turbulent layer downstream of the grooves was then compared with the results from the corresponding smooth-wall case. To conclude, the effect of the spaced triangular riblets on the turbulent… More >