Papers by Keyword: Rotating Disc

Abstract: The paper presents the analysis of plastic indentations resulting after the impact between a steel ball and a disc made of mild steel, rotating about a vertical axis. The imprints are analysed using a laser scanner, the profiles of the mark, in normal and tangent section about the impact point radius, being relevant. It is shown that the use of parabolas is sufficient to approximate the profiles of the imprint. The profiles from the two sections are interpolated and then brought for comparison into the same coordinate system. Finally, the curvature radii of the profiles from the two sections are found and the remark that increasing the angular speed of the disc presents opposite effects to the curvature radius in the two sections.

Abstract: The steady state creep behaviour of a rotating FGM disc having linearly varying thickness has been investigated. The disc is assumed to be made of functionally graded composite containing non-linearly varying radial distribution of silicon carbide particles in a matrix of pure aluminum. The creep behaviour of the composite has been described by threshold stress based law. The effect of varying the disc thickness gradient has been analyzed on the stresses and strain rates in the FGM disc. It is observed that the radial and tangential stresses induced in the FGM disc decrease throughout with the increase in thickness gradient of the disc. The strain rates also decrease with the increase in thickness gradient of the FGM disc, with a relatively higher decrease near the inner radius. The increase in disc thickness gradient results in relatively uniform distribution of strain rates and hence reduces the chances of distortion in the disc.

Abstract: Steady state creep in a anisotropic rotating disc made of Al-SiCp composite having hyperbolically varying thickness has been investigated using Hill’s yield criterion. The creep behavior is supposed to follow the Sherby’s law in present study. The stress and strain distributions are calculated for different combinations of anisotropic constants. The change in the radial stress is not significant while the tangential stress is changed with the change in the material constants. The tangential strain rates are highest at the inner radius of the disc and then decreases towards the outer radius of the disc. The radial strain rate which is compressive in nature becomes tensile in middle of the disc for some specific values of anisotropic constants. The study reveals that the anisotropy has a significant effect on the creep behavior of rotating disc. Thus for the safe design of the rotating disc the effect of anisotropy should be taken care of.

Abstract: In this paper, mechanical and thermal stresses of rotating hollow disks composed of functionally graded materials (FGMs) is presented. The material properties for FG are expressed as nonlinear exponential functions through the radius of disk and Poisson’s ratio is taken to be constant. The temperature distribution is derived from first law thermodynamics by solving energy equation, general thermal and mechanical boundary conditions are assumed on the inside and outside surfaces of the disk. Heat conduction and Navier equations of a FGM disk are expressed in elliptic cylinder coordinates system and solved analytically. The results are shown for displacement and stresses components along the radial direction.

Abstract: Experimental studies of a water drop impinging on a rotating disk using a high-speed video camera have been performed. The photos of the impact were analyzed in detail. Three kinds of the deposition patterns were observed with the variation in Rossby number. It is found that Rossby number plays an important role in the deposition process of the drop impacting on the rotating disk, leading to some new stages not observed for drop impact on a stationary plate.

Abstract: At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 100°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium was measured in pressure clear cyanide solution using a Palladium rotating disk. The data at different rotation speed, different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressuer, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased.The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution were independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and were well below chemical reaction-limited for cyanide and oxygen.

Abstract: Rotating discs are used widely as important structural elements in mechanical engineering. In order to obtain an optimal structural design, it is necessary to estimate the angular velocity and the stress distribution of a rotating disc in fully plastic state. So Large deformation and discontinuous yield analysis of rotating disks were analyzed by ABAQUS. Moreover, continuous yield, buckling and bifurcation analysis of rotating disk with discontinuous yield were studied. Then, Minidisk model is analyzed using ABAQUS.

Abstract: Flywheel rotor performance monitoring and damage detection are increasingly gaining the interest of manufacturers of aircraft engines. This is primary due to the fact that there is a necessity for improving safety during operation as well as a need for lower maintenance costs. Applied techniques for damage detection and health monitoring of rotors are essential for engine safety, reliability and life prediction. Preliminary design of such a flywheel studied here is based on a simple model of annular rotating disk with stress-free boundary conditions. In addition to the critical rotational speed, the paper analyses the influence of the leading design parameter - material plastic anisotropy - on the development of plastic zone and stress/strain distributions.

Abstract: The setup of the surface flow visualisation by electrochemical deposit has given good results in the case of different flow types and in particular in the case of solids in rotation [1- 4]. This technique is based on the mass transfer principle towards a reactive surface electrode on which the studied flow will be visualised. This visualisation method of the surface streamlines by electrochemical deposit has allowed to understand the flow between a rotating and fixed discs. The inlet phenomenal named edge effects have been clearly seen during the visualization and the theoretical study. The purpose of this study is to precise the wide range from the surface streamlines configurations.