L. Dammak, E. Hadj-Taïeb

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.4, pp. 419-430, 2010, DOI:10.3970/fdmp.2010.006.419

Abstract This paper presents a short and focused analysis of the pressure development inside the fluid film related to a journal bearing (i.e. the pressure distribution in the the gap between the shaft, generally referred to as the "journal", and the bearing). The related flow is considered to be isotherm, laminar, steady and incompressible. The lubricant is assumed to be an isoviscous fluid. The Reynolds equation governing the lubricant pressure is derived from the coupled continuity and momentum balance equations written in the framework of the Stokes theory. The non linear system given by coupled equations More >

Nedeltcho K,ev¹, Val Kagan², Ahmed Daoud¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.3, pp. 291-318, 2010, DOI:10.3970/fdmp.2010.006.291

Abstract Results are presented of 3D numerical magneto-hydrodynamic (MHD) simulation of electromagnetic DC pump for both laminar and turbulent metal flow under an externally imposed strongly non-uniform magnetic field. Numerous MHD flow cases were simulated using finite element method and the results of five typical examples are summarized here, including one example of laminar brake flow, one example of turbulent brake flow and three examples of turbulent pumping conditions. These simulations of laminar and turbulent channel flow of liquid metal correctly represent the formation of an M shaped velocity profile and are in good agreement with… More >

R. M. Patel¹, G. M. Deheri², P. A. Vadher³

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.3, pp. 277-290, 2010, DOI:10.3970/fdmp.2010.006.277

Abstract An endeavor has been made to analyze the performance of an infinitely long magnetic fluid based hydrodynamic slider bearing in the presence of a magnetic fluid lubricant. The associated Reynolds' equation is solved with appropriate boundary conditions. Expressions for dimensionless pressure, load carrying capacity and friction are obtained. Computed values are displayed graphically. It is seen that the magnetic fluid lubricant improves the performance of the bearing system. The friction decreases at the moving plate while it increases nominally at the fixed plate due to magnetization. In order to extend the life period of this More >

E. A. Semma¹, M. El Ganaoui², V. Timchenko³, E. Leonardi³

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.3, pp. 233-250, 2010, DOI:10.3970/fdmp.2010.006.233

Abstract The effects of oscillatory heating on thermosolutal convection in a cavity heated from below are investigated and discussed. The transient Navier-Stokes equations coupled with heat and mass balances are solved numerically by using a control-volume technique. It is assumed that the interface moves with constant growth velocity. The results show the presence of multiple solutions in response to simultaneous vertical temperature and species concentration gradients applied to the system. In particular, two critical frequencies are identified, one corresponding to low values of the buoyancy ratio N (N~1), accompanied with a decrease of flow intensity reaching More >

Shaligram Tiwari¹, Koichi Nishino²

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.1, pp. 109-136, 2010, DOI:10.3970/fdmp.2010.006.109

Abstract The present work reports about an experimental study investigating the influence of air convection and of ambient temperature around a half-floating zone on the transition behavior from steady to oscillatory flow, i.e. the influence on the critical Marangoni number (Macr). Increase of heat loss from the free surface of the half-floating zone or liquid bridge by increased convection and ambient cooling decreases Macr. Heat input to the free surface increases Macr. An add-on numerical simulation of the air convection around the zone clarifies the influence of air convection and the ambient temperature on the temperature, More >

X. H. Du¹, X. P. Shen¹

CMC-Computers, Materials & Continua, Vol.20, No.3, pp. 225-242, 2010, DOI:10.3970/cmc.2010.020.225

Abstract Aim of this paper is to estimate the integrity of liquefied natural gas (LNG) prestressed storage tank under seismic influence. The coupled Eulerian-Lagrangian (CEL) analysis technique is used to simulate the fluid-structure interaction between LNG and the cylinder of LNG prestressed storage tank. The 3-D model of LNG has been dispersed by Eulerian mesh that is different from traditional analysis method which is called the added mass method. Meanwhile, both of the 3-D models of prestressed rebar and concrete structure are dispersed by Lagrangian mesh. Following conclusions are obtained: 1) Natural frequency of the whole… More >

X.P. Shen, A. Diaz¹, T. Sheehy²

CMC-Computers, Materials & Continua, Vol.20, No.3, pp. 205-224, 2010, DOI:10.3970/cmc.2010.020.205

Abstract This paper presents a case study for the design of a mud-weight window (MWW) with three-dimensional (3-D), finite-element (FE) tools for subsalt wells. The trajectory of the target well penetrates a 7 km thick salt body. A numerical scheme has been proposed for calculating the shear failure gradient (SFG) and fracture gradient (FG) with 3-D FE software. User subroutines have been developed to address non-uniform pore-pressure distribution. A series of FE calculations were performed to obtain the MWW of the target wellbore, which consists of the SFG and FG for the subsalt sections. Although no… More >

N.J. Bartle¹, P.D. Gosling¹

CMC-Computers, Materials & Continua, Vol.20, No.1, pp. 19-62, 2010, DOI:10.3970/cmc.2010.020.019

Abstract ETFE cushions are increasingly being used to form high-profile facades and structural forms. This investigation aims to extend an analytical theory of large deformation in order to predict the shape and stress distributions of an un-patterned square ETFE cushion without the need to resort to discretised numerical methods. In order to assess the validity of the theoretical procedure a prototype cushion has been analysed using a finite element simulation. The theoretical procedure is also compared with alternative approximate equations proposed for the design of ETFE cushions. More >

S. N.V.R.K. Kurapati¹, Y. C. Lu¹, F. Yang²

CMC-Computers, Materials & Continua, Vol.20, No.1, pp. 1-18, 2010, DOI:10.3970/cmc.2010.020.001

Abstract The spherical indentation of elastic film /substrate structures is analyzed using the finite element method. The load-displacement curves of the film /substrate structures of various configurations are obtained and analyzed. A generalized power law relation is established, which can be used to analyze the load-displacement curve of elastic film /substrate systems under spherical indentations. The indentation load is dependent on the modulus ratio of the film to the substrate and film thickness. A semi-analytical expression for the power of the power law relation is also obtained as a function of the normalized film thickness and More >

Adel A. Abdel-Wahab¹, Angelo Maligno¹, Vadim V. Silberschmidt¹

CMC-Computers, Materials & Continua, Vol.19, No.3, pp. 217-238, 2010, DOI:10.3970/cmc.2010.019.217

Abstract Bone is the principal structural component of a skeleton: it assists the load-bearing framework of a living body. Structural integrity of this component is important; understanding of its mechanical behaviour up to failure is necessary for prevention and diagnostic of trauma. In dynamic events such as traumatic falls, involvement in car crash and sports injuries, bone can be exposed to loads exceeding its structural strength and/or fracture toughness. By developing adequate numerical models to predict and describe its deformation and fracture behaviour up to fracture, a detailed study of reasons for, and ways to prevent… More >