Daisuke Ishihara^*, Syunnosuke Nozaki, Tomoya Niho, Naoto Takayama

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 1371-1386, 2024, DOI:10.32604/cmes.2024.049694 - 20 May 2024

Abstract The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy harvesters. Existing strongly coupled analysis methods based on direct numerical modeling for this phenomenon can be classified into partitioned or monolithic formulations. Each formulation has its advantages and disadvantages, and the choice depends on the characteristics of each coupled problem. This study proposes a new option: a coupled analysis strategy that combines the best features of the existing formulations, namely, the hybrid partitioned-monolithic method. The analysis of inverse piezoelectricity and the monolithic analysis of direct piezoelectric More >

Shigeki Kaneko¹, Naoto Mitsume², Shinobu Yoshimura^1,*

Digital Engineering and Digital Twin, Vol.2, pp. 33-48, 2024, DOI:10.32604/dedt.2023.044279 - 31 January 2024

Abstract In an integrated coal gasification combined cycle plant, cooling pipes are installed in the gasifier reactor and water cooling is executed to avoid reaching an excessively high temperature. To accelerate the design, it is necessary to develop an analysis system that can simulate the cooling operation within the practical computational time. In the present study, we assumed the temperature fields of the cooled object and the cooling water to be governed by the three-dimensional (3D) heat equation and the one-dimensional (1D) convection-diffusion equation, respectively. Although some existing studies have employed similar modeling, the applications have… More >

Daisuke Ishihara^*, Naoto Takayama

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1237-1258, 2024, DOI:10.32604/cmes.2023.030211 - 17 November 2023

Abstract In this study, we propose an algorithm selection method based on coupling strength for the partitioned analysis of structure-piezoelectric-circuit coupling, which includes two types of coupling or inverse and direct piezoelectric coupling and direct piezoelectric and circuit coupling. In the proposed method, implicit and explicit formulations are used for strong and weak coupling, respectively. Three feasible partitioned algorithms are generated, namely (1) a strongly coupled algorithm that uses a fully implicit formulation for both types of coupling, (2) a weakly coupled algorithm that uses a fully explicit formulation for both types of coupling, and (3) More >

S. Satham Hussain¹, G. Muhiuddin^2,*, N. Durga³, D. Al-Kadi⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 559-580, 2022, DOI:10.32604/cmes.2022.017032 - 29 November 2021

Abstract The partition of indeterminacy function of the neutrosophic set into the contradiction part and the ignorance part represent the quadripartitioned single valued neutrosophic set. In this work, the new concept of quadripartitioned bipolar single valued neutrosophic graph is established, and the operations on it are studied. The Cartesian product, cross product, lexicographic product, strong product and composition of quadripartitioned bipolar single valued neutrosophic graph are investigated. The proposed concepts are illustrated with examples. More >

Jie Ling^1,2, Xinmei Li^1,2, Mingwei Lin^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.1, pp. 117-148, 2021, DOI:10.32604/cmes.2021.016356 - 24 August 2021

Abstract During the COVID-19 outbreak, the use of single-use medical supplies increased significantly. It is essential to select suitable sites for establishing medical waste treatment stations. It is a big challenge to solve the medical waste treatment station selection problem due to some conflicting factors. This paper proposes a multi-attribute decision-making (MADM) method based on the partitioned Maclaurin symmetric mean (PMSM) operator. For the medical waste treatment station selection problem, the factors or attributes (these two terms can be interchanged.) in the same clusters are closely related, and the attributes in different clusters have no relationships.… More >

Suvash C. Saha^1,*, Ali M. Sefidan², Atta Sojoudi³, Mohammad M. Molla⁴

Energy Engineering, Vol.118, No.3, pp. 487-506, 2021, DOI:10.32604/EE.2021.014088 - 22 March 2021

Abstract One primordial consideration in residential ventilation standards is the comfort of provided to people living in those habitations. This is highly dependent on the thermal and fluid flow conditions, the space geometry and so on. Efficient designs may reduce the energy usage, making the buildings more sustainable over a longer period of time. This study aims to investigate the impact of whole day thermal conditions on the fluid flow structure and heat transfer phenomena, mainly natural convection, inside a partitioned attic-shaped configuration. The Finite Volume Method is applied to solve the governing equations. Sinusoidal thermal… More >

Minato Onishi¹, Daisuke Ishihara^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 145-175, 2019, DOI:10.32604/cmes.2019.06781

Abstract This study proposed a partitioned method to analyze maneuvering of insects during flapping flight. This method decomposed the insect flapping flight into wing and body subsystems and then coupled them via boundary conditions imposed on the wing’s base using one-way coupling. In the wing subsystem, the strong coupling of the flexible wings and surrounding fluid was accurately analyzed using the finite element method to obtain the thrust forces acting on the insect’s body. The resulting thrust forces were passed from the wing subsystem to the body subsystem, and then rigid body motion was analyzed in… More >

Changgeng Shuai^{1, 2}, Shike Zhang^{1, 2}, Jiaxuan Yang^{1, 2}, Sitong Zhou^{1, 2}

Sound & Vibration, Vol.52, No.4, pp. 2-5, 2018, DOI:10.32604/sv.2018.03724

Abstract Advanced array processing approaches require accurate knowledge of the location of individual element in a sensor array. Most array shape estimation methods require the directions of sources. In this paper, an array shape estimation method based on eigen-decomposition is presented. The directions of sources do not need to be considered in advance and optimal array shape is generated through a series of iterations. To further improve the accuracy of this algorithm, a partitioned eigenstructure method is introduced. Numerical simulations using non-partitioned and partitioned method are conducted to verify the performance of the proposed technique. More >

Yasunori Yusa¹, Shinobu Yoshimura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.1, pp. 87-104, 2014, DOI:10.3970/cmes.2014.099.087

Abstract To speed up the elastic–plastic analysis of a large-scale model with a crack in which plasticity is observed near the crack, the partitioned coupling method is applied. In this method, the entire analysis model is decomposed into two non-overlapped domains (i.e., global and local domains), and the two domains are analyzed with an iterative method. The cracked local domain is modeled as an elastic–plastic body, whereas the large-scale global domain is modeled as an elastic body. A subcycling technique is utilized for incremental analysis to reduce the number of global elastic analyses. For a benchmark More >

Yasunori Yusa¹, Shinobu Yoshimura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.91, No.6, pp. 445-461, 2013, DOI:10.3970/cmes.2013.091.445

Abstract For large-scale fracture mechanics simulation, a partitioned iterative coupling method is investigated. In this method, an analysis model is decomposed into two domains, which are analyzed separately. A crack is introduced in one small domain, whereas the other large domain is a simple elastic body. Problems concerning fracture mechanics can be treated only in the small domain. In order to satisfy both geometric compatibility and equilibrium on the domain boundary, the two domains are analyzed repeatedly using an iterative solution technique. A benchmark analysis was performed in order to validate the method and evaluate its More >