S. Gururaja¹, M. Ramulu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 73-80, 2007, DOI:10.3970/icces.2007.004.073

Abstract Uni-Directional Fiber-Reinforced Plastic (UD-FRP) laminates have been modeled as a quasi-homogeneous monoclinic half-space subjected to an inclined load at the surface. Complete closed form stress-fields derived previously [1] based on Lekhtinskii's formulation [2] in conjunction with the principle of analytical continuation [3] were used to study the stress-response in relation to a few parameters identified, namely, fiber-orientation, load inclination angle and spatial coordinates with respect to line load application position in the half-space domain. More >

Pramod Kumar¹, Rakesh Chandra¹, S.P. Singh²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 67-72, 2007, DOI:10.3970/icces.2007.004.067

Abstract Polymers composite are modeled as fiber, interphase and matrix. Interphase properties are very crucial for bonding between fiber and matrix. Interphase can be strong and weak depending upon its properties. Damping of composite material depends on interphase properties and required damping can be obtained by varying the properties of interphase. In this paper three phase mathematical model has been proposed for the evaluation of damping incorporating the effect of fiber packing. Effect of interphase has been analysed for the longitudinal loss factor, transverse loss factor, transverse shear loss factor and longitudinal shear loss factor. Results obtained by modeling fiber reinforced… More >

Christos C. Chamis¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 59-66, 2007, DOI:10.3970/icces.2007.004.059

Abstract A formal procedure for the probabilistic design evaluation of a composite structure is described. The uncertainties in all aspects of a composite structure (constituent material properties, fabrication variables, structural geometry, and service environments, etc.), which result in the uncertain behavior in the composite structural responses, are included in the evaluation. The probabilistic evaluation consists of: (1) design criteria, (2) modeling of composite structures and uncertainties, (3) simulation methods, and (4) the decision-making process. A sample case is presented to illustrate the formal procedure and to demonstrate that composite structural designs can be probabilistically evaluated with accuracy and efficiency. More >

V.C. Santos¹, P.S. Lopes¹, R. Gärtner², A.B. Jorge¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 53-58, 2007, DOI:10.3970/icces.2007.004.053

Abstract This work presents an approach for weight and reliability optimization of aeronautical armors. Military and police helicopters are usually exposed to highly risky situations, with a high probability for these aircrafts to be hit by projectiles. In this context, floor aircraft armor can be used to protect the crews' lives. However, the armoring of an aircraft causes an increase in weight. If this extra weight is poorly arranged, the changes in aircraft centroid position may even destabilize the aircraft. Thus, it is essential to design an armor not only to protect the aircraft, but also not to conflict with aircraft… More >

B.S. Sousa¹, D.R. Petrucci¹, A.B. Jorge¹, N. Manzanares-Filho¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.1, pp. 47-52, 2007, DOI:10.3970/icces.2007.004.047

Abstract The use of computational methods in modern engineering is an irreversible trend, especially in the field of aerodynamics. The validation of these methods is an essential part of their development. In many situations this validation can be made by using experimental results. In other situations, particularly for potential flow methods, the validation can be made by using analytical results (Joukowski, Karman-Trefftz and Van de Vooren airfoils, for example). In general situations, however, especially when no analytical solutions are available (for example, NACA airfoils series), it is highly desirable to know the errors due to the use of numerical methods in… More >

K. Inaba¹, M. Yamamoto², J.E. Shepherd³, A. Matsuo⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.1, pp. 41-46, 2007, DOI:10.3970/icces.2007.004.041

Abstract The purpose of this research is to explore an explanation of detonation soot track formation, comparing with previous hypothesis of formation mechanism. Focusing on the role of shear stress in transporting soot along the surface, we investigated the non-reactive Mach reflections numerically with three-dimensional compressible Navier-Stokes simulations. Numerical results are compared with a two-dimensional detonation simulation and used to investigate the effect of shear stress spatial and temporal variations on soot redistributions. The motions of soot due to surface shear stress are numerically examined with treating soot as particles and fluid parcel. 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 >

J. Kato¹, K. Inaba², M. Yamamoto³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.1, pp. 25-30, 2007, DOI:10.3970/icces.2007.004.025

Abstract Pulse detonation turbine engines (PDTEs), which are used as power generation, are desirable to use hydrocarbon from the aspect of infrastructure of fuels. In the present study, we investigate the performance of PDEs using mixed hydrocarbon fuels. With the detailed 42-species and 168-step mechanism, numerical simulations on mixed-fuel-and-air PDEs are conducted. We use CH4-C3H8, CH4-H2, and C3H8-H2 as fuels, and examine characteristic features of detonations with different blend ratios. We perform calculations on the Chapman-Jouguet detonation speeds and chemical reaction lengths, and investigate ZND profiles of chemical reactions. Then we evaluate PDEs performances by changing blend ratios. These results show… More >

Shigeaki Shiotani¹, Atsushi Hagiwara², Yoshitaka Sakakura³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.1, pp. 19-24, 2007, DOI:10.3970/icces.2007.004.019

Abstract Marine fish larvae are fragile against physical stress. However, few studies have been conducted to evaluate the flow field in a rearing tank, which is assumed to provide a high degree of physical stress to marine fish larvae. This paper is a report on the numerical estimation of stationary flow in the rearing tank of marine fish larvae. The calculated flow in the rearing tank was compared with the experimental one. The calculation of the stationary flow in the rearing tank showed good qualitative and quantitative agreement with the experimental results. More >

Kazuhiko Kakuda¹, Tomohiro Aiso¹, Shinichiro Miura²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.1, pp. 11-18, 2007, DOI:10.3970/icces.2007.004.011

Abstract The applications of a finite element scheme to three-dimensional incompressible viscous fluid flows are presented. The scheme is based on the Petrov-Galerkin weak formulation with exponential weighting functions. The incompressible Navier-Stokes equations are numerically integrated in time by using a fractional step strategy with second-order accurate Adams-Bashforth scheme for both advection and diffusion terms. Numerical solutions for flow around a circular cylinder and flow around a railway vehicle in a tunnel are presented. More >