Showing papers by "R. Usha published in 2001"
TL;DR: In this article, the development of a heat conducting fluid film on a rotating disk has been analyzed numerically under the planar interface assumption and the film thickness, the flow characteristics, the temperature distribution and the rate of heat transfer are determined.
Abstract: The development of a heat conducting fluid film on a rotating disk has been analysed numerically under the planar interface assumption and the film thickness, the flow characteristics, the temperature distribution and the rate of heat transfer are determined. The range of validity of the time scales and Reynolds number bounds have been presented for the existing asymptotic solution for film cooling on a rotating disk. The effects of the Reynolds number Re , cooling parameter β and the Prandtl number σ on the variation of film thickness, and temperature distribution have been examined.
13 citations
TL;DR: In this article, a numerical solution for the development of a conducting fluid film on the surface of a spinning disc, in the presence of a magnetic field applied perpendicular to the disc, was obtained for the Navier-Stokes equations modified to include magnetic forces due to MHD interactions.
Abstract: A numerical solution is obtained for the development of a conducting fluid film on the surface of a spinning disc, in the presence of a magnetic field applied perpendicular to the disc. A finite-difference method is employed to obtain the solution of Navier-Stokes equations modified to include magnetic forces due to MHD interactions. The combined effects of film inertia, acceleration of the disc and magnetic forces are analysed. The numerical results reveal that the rate of thinning of the fluid film is strongly influenced by the inertial and magnetic forces when the Reynolds number is large and that the existing asymptotic theory by Ray and Dandapat [24] is inadequate for predicting transient film thickness. When the disc has a finite acceleration at the start-up, the magnetic and inertia effects are important even at low Reynolds numbers and the thinning rate is reduced. It is observed that for both low and high Reynolds number flows, the film thickness increases with Hartmann numberM for a fixed time and the rate of depletion is less for largeM than for smallM.
5 citations
4 citations
TL;DR: In this paper, the development of a viscous conducting fluid over a rough spinning disk in the presence of a transverse magnetic field has been analyzed for different patterns of surface roughness of the disk and different initial distributions of the height of the liquid lubricant.
Abstract: The development of a flow of a viscous conducting fluid over a rough spinning disk in the presence of a transverse magnetic field has been analysed for different patterns of surface roughness of the disk and different initial distributions of the height of the liquid lubricant. The numerical solution of the governing equation of motion subject to initial and boundary conditions has been obtained by a finite-difference method. The temporal evolution of the free surface of the fluid and the rate of retention of the liquid lubricant on the spinning disk have been obtained for different values of the two parameters M , the Hartmann number and Nratio, the ratio of the surface tension effect to the centrifugation effect. In the absence of the magnetic field, the results have been observed to agree with those of [6]. It has been observed that the effect of surface roughness is to enhance the relative volume of the fluid retained on the spinning disk and this is further enhanced by the presence of the magnetic field.
2 citations