Shishir Sinha¹, Praveen Ch.

CMES-Computer Modeling in Engineering & Sciences, Vol.32, No.2, pp. 85-102, 2008, DOI:10.3970/cmes.2008.032.085

Abstract Fluid catalytic cracking (FCC) unit plays most important role in the economy of a modern refinery that it is use for value addition to the refinery products. Because of the importance of FCC unit in refining, considerable effort has been done on the modeling of this unit for better understanding and improved productivity. The process is characterized by complex interactions among feed quality, catalyst properties, unit hardware parameters and process conditions. \newline The traditional and global approach of cracking kinetics is lumping. In the present paper, five lump kinetic scheme is considered, where gas oil crack to give lighter fractions… More >

F. Cosmi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.27, No.3, pp. 187-196, 2008, DOI:10.3970/cmes.2008.027.187

Abstract The Cell Method is a recent numerical method that can be applied in several fields of physics and engineering. In this paper, the elastodynamics formulation is extended to include system internal damping, highlighting some interesting characteristics of the method. The developed formulation leads to an explicit solving system. The mass matrix is diagonal (without lumping) and in the most general case a time-dependent damping coefficient can be defined for each node. \newline Accuracy and convergence rate have been tested with reference to the classical problem of a particle free vibration with viscous damping.
An application to mechanical components analysis… More >

Chein-Shan Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.27, No.3, pp. 137-150, 2008, DOI:10.3970/cmes.2008.027.137

Abstract For the inverse vibration problem, a Lie-group shooting method is proposed to simultaneously estimate the time-dependent damping and stiffness functions by using two sets of displacement as inputs. First, we transform these two ODEs into two parabolic type PDEs. Second, we formulate the inverse vibration problem as a multi-dimensional two-point boundary value problem with unknown coefficients, allowing us to develop the Lie-group shooting method. For the semi-discretizations of PDEs we thus obtain two coupled sets of linear algebraic equations, from which the estimation of damping and stiffness coefficients can be written out explicitly. The present approach is very interesting, which… More >

D. Moens¹, M. De Munck, D. Vandepitte

CMES-Computer Modeling in Engineering & Sciences, Vol.22, No.2, pp. 129-150, 2007, DOI:10.3970/cmes.2007.022.129

Abstract Recently, an interval finite element methodology has been developed to calculate envelope frequency response functions of uncertain structures with interval parameters. The methodology is based on a hybrid interval implementation of the modal superposition principle. This hybrid procedure consists of a preliminary optimization step, followed by an interval arithmetic procedure. The final envelope frequency response functions have been proved to give a very good approximation of the actual response range of the interval problem. Initially, this method was developed for undamped structures. Based on the theoretical principles of this approach, this paper introduces a new method for the analysis of… More >

Anuj Pratap Singh, V. Mani, Ranjan Ganguli¹

CMES-Computer Modeling in Engineering & Sciences, Vol.21, No.2, pp. 133-148, 2007, DOI:10.3970/cmes.2007.021.133

Abstract This paper investigates the use of Genetic Programming (GP) to create an approximate model for the non-linear relationship between flexural stiffness, length, mass per unit length and rotation speed associated with rotating beams and their natural frequencies. GP, a relatively new form of artificial intelligence, is derived from the Darwinian concept of evolution and genetics and it creates computer programs to solve problems by manipulating their tree structures. GP predicts the size and structural complexity of the empirical model by minimizing the mean square error at the specified points of input-output relationship dataset. This dataset is generated using a finite… More >

Heng Xie¹, Seiichi Koshizuka², Yoshiaki Oka²

CMES-Computer Modeling in Engineering & Sciences, Vol.18, No.1, pp. 1-16, 2007, DOI:10.3970/cmes.2007.018.001

Abstract A model of a single liquid drop colliding on solid surface is developed based with Moving Particle Semi-implicit (MPS) method. The mathematical model involves gravity, viscosity and surface tension. The wettability between the impact liquid and the solid surface is modeled by the contact angle model and the non-slip boundary condition. The particles of the drop are divided into four types in which the model varies to simulate the liquid particles in different area. The model is validated by the comparison of the theoretical results. The complete dynamic process including the spreading, the recoiling, re-bouncing and splashing is simulated and… More >

Fatiha Bentarzi¹, Amina Mataoui^{1, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.2, pp. 107-120, 2018, DOI: 10.3970/fdmp.2018.06046

Abstract The dynamics of two fully developed turbulent jets, perpendicular to a heated flat plate and related heat transfer mechanism are analysed numerically. This problem is relevant to several thermal engineering applications. The governing equations are solved by a finite volume method with a second order RSM model combined with wall functions used for turbulent modelling. The possibility to improve heat transfer is assessed taking into account the characteristic parameters for the jet-wall interaction. In particular, a parametric study is conducted by varying the jet Reynolds number (Re) and the nozzle to plate distance (D). The distance between the two jets… More >

F. Iachachene¹, A. Matoui², Y. Halouane¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 503-520, 2014, DOI:10.3970/fdmp.2014.010.503

Abstract Computations related to a heat transfer and fluid flow of a plane isothermal fully developed turbulent plane jet flowing into a rectangular hot cavity are reported in this paper. Both velocity and temperature distributions are computed by solving the two-dimensional Unsteady Reynolds Averaged Navier--Stokes (URANS) equations. This approach relies on one point statistical modeling based on the energy - specific dissipation (k-ω) turbulence model. The numerical simulations are carried out in the framework of a finite volume method. This problem is relevant to a wide range of practical applications including forced convection and the ventilation of mines, enclosure or corridors.… More >

D. Benmouhoub¹, A. Mataoui¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 241-260, 2014, DOI:10.3970/fdmp.2014.010.241

Abstract The present work is devoted to the numerical study of the interaction of an inclined plane turbulent jet with a moving horizontal isothermal hot wall. The inclination of the jet allows the control of the stagnation point location. Numerical predictions based on statistical modeling are obtained using a second order Reynolds stress turbulence model coupled to an enhanced wall treatment. For a given impinging distance H (H =8e), the considered problem parameters are: (a) jet exit Reynolds number (Re, based on the thickness "e" of the nozzle) in the range from 10000 to 25000, (b) surface-to-jet velocity ratio Rsj from… More >

J.R. Lin¹, L.M. Chu², T.L. Chou³, L.J. Liang³, P.Y. Wang³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 163-177, 2014, DOI:10.3970/fdmp.2014.010.163

Abstract We investigate the influence of non-Newtonian micropolar fluids on the dynamic characteristics of wide tapered-land slider bearings. The study is carried out on the basis of the micro-continuum theory originally developed by Eringen (1966). Analytical expressions for the linear dynamic coefficients are provided and compared with earlier results in the literature. In particular, direct comparison with the Newtonian fluid-lubricated tapered-land bearings by Lin et al. (2006) indicates that the use of non-Newtonian micropolar fluids can lead to a significant increase in the values of stiffness and damping coefficients. Such improvements are found to be even more pronounced for larger values… More >