S.S. Kim, S.M. Chang¹, H.S. Jeong

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 9-10, 2009, DOI:10.3970/icces.2009.012.009

Abstract In this paper, the three-dimensional model of a servo valve working in the fuel supply system of auxiliary power unit (APU) for the gas turbine engine is studied with numerical simulation of multiphysical system. The physics of electromagnetics, structural dynamics, and fluid dynamics are expressed in the form of independent system of partial differential equations, respectively. A commercial code named COMSOL is used to simulate the essential physics of the servo valve system, and the extracted data is used for the simulation of entire servo valve, which is coupled with torque motor, bushing tube, and valve orifice, etc. The valve… More >

Ji Won Yoon¹, Tae Won Park², Kab Jin Jun³, Soo Ho Lee³, Sung Pil Jung³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.3, pp. 73-74, 2009, DOI:10.3970/icces.2009.011.073

Abstract Industrial vehicles like forklifts are used in many areas, such as the heavy industries, shipbuilding, and manufacturing industries. Recently, the rise in the oil prices and stricter environmental regulations have created the need for new technologies for industrial vehicles. Presently, the performance of the power train has reached its limit and cannot be further improved without increasing cost, weight and volume. Therefore, a system based on a new paradigm is needed. To achieve this goal, the structure of the power transfer system needs to be revolutionized. First, weight and size need to be reduced. In addition, the number of gears… More >

B. Gatmiri¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.3, pp. 159-166, 2007, DOI:10.3970/icces.2007.004.159

Abstract This document summarizes the basic concepts and steps of establishment of the set of equations of wave propoagation in far field and of the dynamic behaviour of porous media in the near field. A breif description of HYBRID software as a powerful tool for evaluation of local seismic site effect is presented. The Combination of the FEM and BEM and improvement of numerical algorithm for the time truncation are described. More >

Dr. V. Ramani Bai, Prof. Mohamad Rom Tamjis

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.1, pp. 31-40, 2007, DOI:10.3970/icces.2007.004.031

Abstract The aim of this paper is to develop a fuzzy logic model for deriving optimal operational rules at the macro level for better performance and control of hydro-power generation. System modeling based on conventional mathematical tools is not well suited for dealing with ill-defined and uncertain systems. By contrast, a fuzzy inference system employing "if-then" rules can model the qualitative aspects of human knowledge and reasoning processes without employing precise quantitative analyses. In fuzzy logic, diagnosis is based on imprecise data. For instance, when the demand is `very high' i.e. in linguistic term, then its value is important in assisting… More >

Heekun Ju, Hyung-Jo Jung^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.1, pp. 7-7, 2019, DOI:10.32604/icces.2019.05846

Abstract Latin hypercube sampling (LHS) is widely applied to estimate a probabilistic floor response spectrum (FRS) of nonlinear nuclear power plant (NPP) structure. ASCE 4-16 Standards recommend that the minimum number of simulations should be larger than 30 when using LHS. Although this recommendation is commonly used for the minimum number of the simulation, there is no theoretical background. The variability of the estimations may exist according to the number of the simulation. Stated differently, the minimum number of the simulation may be varied depending on the characteristics of the problem (i.e., problem-dependent). In this context, the required sample size of… More >

Hyung-Jo Jung, Heekun Ju

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.1, pp. 6-6, 2019, DOI:10.32604/icces.2019.05761

Abstract The floor response spectrum (FRS) of a nuclear power plant (NPP) structure considering nonlinear behavior of shear walls is numerically investigated. The Hysteretic Material from OpenSees program is applied to a lumped-mass model to consider the nonlinear hysteretic behavior of the element representing the shear wall. Parameters that determine the hysteretic behavior are changed to examine the effects of the parameters on the resulting FRS. The pinching effect, damage due to ductility and energy, and degraded unloading stiffness can be considered with changes in parameter values. The hysteretic behavior of the structure with different parameter values was analyzed. Elements in… More >

P. Shanmugapriya¹, J. Baskaran², C. Nayanatara^1,*, D. P. Kothari³

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 541-558, 2019, DOI:10.32604/cmes.2019.04074

Abstract The objective of this paper is to provide a robust Virtual Power Plant (VPP) network collaborated with Internet of Things (IoT) which uses a conceptual model to integrate each device in the grid. Based on the functionality all the devices which are purely distributed within the grid are networked initially from residential units to substations and up to service data and demand centres. To ensure the trapping of the available power and the efficient transfer of Distributed Generation (DG) power to the grid Distribution Active Control (DAC) strategy is used. Synchronized optimization of DG parameter which includes DG size, location… More >

Muhammad Arsalan¹, Falin Wu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.2, pp. 249-261, 2019, DOI:10.32604/cmes.2019.04430

Abstract A good design of LNA for S band satellite navigation receivers and 4G LTE wireless communication system has been implemented in this paper. Due to increased congestion in the present L band, the S Band frequency from 2483.5-2500 MHz has been allocated for the future satellite navigation systems. For this purpose ATF-34143 amplifier (pHEMT) having high electron mobility and fast switching response has been chosen due to its very low Noise Figure (NF). The amplifier has been designed having bandwidth of 0.8 GHz from 1.8-2.6 GHz. Because of the large bandwidth, the amplifier could serve many wireless communication applications including… More >

Luoding Zhu^1,∗

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.1, pp. 125-143, 2019, DOI:10.32604/cmes.2019.04828

Abstract Problems involving fluid flexible-structure interactions (FFSI) are ubiquitous in engineering and sciences. Peskin’s immersed boundary (IB) method is the first framework for modeling and simulation of such problems. This paper addresses a three-dimensional extension of the IB framework for non-Newtonian fluids which include power-law fluid, Oldroyd-B fluid, and FENE-P fluid. The motion of the non-Newtonian fluids are modelled by the lattice Boltzmann equations (D3Q19 model). The differential constitutive equations of Oldroyd-B and FENE-P fluids are solved by the D3Q7 model. Numerical results indicate that the new method is first-order accurate and conditionally stable. To show the capability of the new… More >

G.Ananthakrishna¹

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.3, pp. 233-240, 2005, DOI:10.3970/cmes.2005.007.233

Abstract We show that the extended Ananthakrishna's model exhibits all the features of the Portevin - Le Chatelier effect including the three types of bands. The model reproduces the recently observed crossover from a low dimensional chaotic state at low and medium strain rates to a high dimensional power law state of stress drops at high strain rates. The dynamics of crossover is elucidated through a study of the Lyapunov spectrum. More >