LAMINAR FLOW IN A UNILATERALLY ROUGH CHANNEL

1998 ◽  
Vol 22 (4A) ◽  
pp. 311-324
Author(s):  
Jin Hu ◽  
H. J Leutheusser

This paper deals with an analytical and experimental investigation of laminar sheet flow between a smooth and a rough wall. As such, the material presented may be of special interest within the context of hydrodynamic lubrication. The dynamic and kinematic properties of the flow are described by a newly conceived “reduced Reynolds number”, and the two length parameters of, respectively, “relative roughness” and “steepness of roughness”. The equations of motion are solved by the finite element method for the case of sinusoidal roughness, and corresponding measurements are obtained in a specially designed two-dimensional wind-tunnel. Good agreement is found to exist between numerical and experimental results. The pattern of streamlines and velocity profiles reflect the influence of the three similitude parameters and thereby underline the important role played by surface texture in laminar sheet flow.

Author(s):  
Matthieu Tourbier ◽  
Bernard Peseux ◽  
Bundi Donguy ◽  
Laurent Gornet

This paper deals with the slamming phenomenon for deformable structures. In a first part, a three-dimensional hydrodynamic problem is solved numerically with the Finite Element Method. The results for a rigid body are successfully compared to the analytical solutions. After the numerical analysis, an experimental investigation is presented. It consists in series of free fall drop-tests of rigid, deformable cones shaped models with different deadrise angle and thickness. Distribution of the pressure and its evolution are analyzed. Numerical and experimental results are compared and present good agreement.


Author(s):  
C T F Ross ◽  
A P F Little ◽  
L Chasapides ◽  
J Banks ◽  
D Attanasio

The paper presents a theoretical and an experimental investigation into the free vibration of three ring-stiffened prolate domes in air and under external water pressure. The theoretical investigation was via the finite element method where a solid fluid mesh was used to model the water surrounding each dome. Good agreement was found between theory and experiment. Both the theory and the experiment found that, as the external water pressure was increased, the resonant frequencies decreased.


Author(s):  
C T F Ross ◽  
W D Richards

This paper describes a theoretical and an experimental investigation into the vibration of three ring-stiffened thin-walled conical shells, under external water pressure. The theoretical investigation was via the finite element method for both the shell structure and the surrounding water. Various fluid meshes were chosen, and a relatively simple one showed good agreement between experiment and theory.


Author(s):  
Neander Berto Mendes ◽  
Lineu José Pedroso ◽  
Paulo Marcelo Vieira Ribeiro

ABSTRACT: This work presents the dynamic response of a lock subjected to the horizontal S0E component of the El Centro earthquake for empty and completely filled water chamber cases, by coupled fluid-structure analysis. Initially, the lock was studied by approximation, considering it similar to the case of a double piston coupled to a two-dimensional acoustic cavity (tank), representing a simplified analytical model of the fluid-structure problem. This analytical formulation can be compared with numerical results, in order to qualify the responses of the ultimate problem to be investigated. In all the analyses performed, modeling and numerical simulations were done using the finite element method (FEM), supported by the commercial software ANSYS.


1992 ◽  
Vol 20 (4) ◽  
pp. 230-253 ◽  
Author(s):  
T. Akasaka ◽  
K. Kabe ◽  
M. Koishi ◽  
M. Kuwashima

Abstract The deformation behavior of a tire in contact with the roadway is complicated, in particular, under the traction and braking conditions. A tread rubber block in contact with the road undergoes compression and shearing forces. These forces may cause the loss of contact at the edges of the block. Theoretical analysis based on the energy method is presented on the contact deformation of a tread rubber block subjected to compressive and shearing forces. Experimental work and numerical calculation by means of the finite element method are conducted to verify the predicted results. Good agreement is obtained among these analytical, numerical, and experimental results.


2014 ◽  
Vol 214 ◽  
pp. 143-150
Author(s):  
Piotr Graca

The paper presents numerical modeling of an Axial Active Magnetic Bearing (AAMB) based on two-dimensional (2D) magnetic field computation. The calculations, assisted by the Finite Element Method (FEM), have focused on the determination of the magnetic flux density and the magnetic force. Obtained magnetic field parameters were then measured and verified on a physical model.


Author(s):  
Ye-Chen Lai ◽  
Timothy C. S. Liang ◽  
Zhenxue Jia

Abstract Based on hierarchic shape functions and an effective convergence procedure, the p-version and h-p adaptive analysis capabilities were incorporated into a finite element software system, called COSMOS/M. The range of the polynomial orders can be varied from 1 to 10 for two dimensional linear elastic analysis. In the h-p adaptive analysis process, a refined mesh are first achieved via adaptive h-refinement. The p-refinement is then added on to the h-version designed mesh by uniformly increasing the degree of the polynomials. Some numerical results computed by COSMOS/M are presented to illustrate the performance of these p and h-p analysis capabilities.


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