Boundary Layer Measurements at an Internal Free Surface in a Partially Filled Horizontal and Rapidly-Rotating Container

1989 ◽  
Vol 111 (4) ◽  
pp. 457-463 ◽  
Author(s):  
T. J. Singler
Keyword(s):  
Boundary Layer ◽  
Free Surface ◽  
Circular Cylinder ◽  
Steady Flow ◽  
Symmetry Axis ◽  
Azimuthal Velocity ◽  
Free Surfaces ◽  
Horizontal Circular Cylinder ◽  
Good Agreement

Steady flow in a partially filled horizontal circular cylinder rotating rapidly about its symmetry axis is investigated experimentally. Radial boundary layer profiles of the azimuthal velocity in the neighborhood of the internal free surface are reported for a range of inverse Froude numbers and for two types of free surfaces. Results indicate good agreement with an existing theory.

Free-Surface Boundary-Layer Approach to Study the Bow Vortices Generation Ahead of a Semisubmerged Horizontal Circular Cylinder

1995 ◽  
Vol 39 (04) ◽  
pp. 284-296
Author(s):  
L. R. Raheja
Keyword(s):  
Boundary Layer ◽  
Free Surface ◽  
Circular Cylinder ◽  
The Body ◽  
Instability Criterion ◽  
Surface Boundary ◽  
Surface Shear ◽  
Surface Boundary Layer ◽  
Surface Separation ◽  
Horizontal Circular Cylinder

In the light of experimental observation of a free-surface shear layer, the flow ahead of a semisubmerged horizontal circular cylinder is modeled as a free-surface boundary layer of concentrated vorticity joining the potential flow below it with the aim to study the generation of bow vortices theoretically. The boundary-layer equations are linearized subject to a suitable assumption and are integrated using basically the Kármán Pohlhausen method. It is found that the free surface moves slower than the layer beneath it, but there is more likelihood of bow vortices being generated by instability of velocity profile rather than by separation and backflow. This is confirmed by the nonmonotonicity in the vorticity profile and the fulfillment of the Görtler instability criterion for flow along curved boundaries, near the body upstream. The position of the point of onset of instability, as stipulated from the above observations, compares well with the position of the free-surface separation point as observed in the experiments.

Flow in a partially filled, rotating, tapered cylinder

1989 ◽  
Vol 203 ◽  
pp. 541-555
Author(s):  
R. J. Ribando ◽  
J. L. Palmer ◽  
J. E. Scott
Keyword(s):  
Boundary Layer ◽  
Free Surface ◽  
Azimuthal Velocity ◽  
Frame Of Reference ◽  
Radial Dependence ◽  
Laser Doppler Velocimeter ◽  
Axial Component ◽  
Vertical Sidewall ◽  
Computational Mesh ◽  
Rotor Wall

The secondary flow patterns induced by a differentially rotating lid in a partially filled, rapidly rotating, tapered cylinder have been investigated. Using a new laser-Doppler velocimeter system capable of making measurements in the rotor frame of reference, the radial dependence of the azimuthal and axial velocity components was measured at two axial positions in the rotor. A linear, asymptotic analysis and a finite-difference simulation were made for comparison. The latter was performed on a boundary-fitted computational mesh so that the slanted rotor wall and the sagging free surface could be accommodated in the model. The agreement between the experimental and numerical results was excellent for the azimuthal velocity component and good for the axial component. Of particular interest is the modified E½ boundary layer on the slanted wall, a feature which is not present with a vertical sidewall.

EFFECTS OF SURFACE TENSION ON TRAPPED MODES IN A TWO-LAYER FLUID

2015 ◽  
Vol 57 (2) ◽  
pp. 189-203 ◽  
Author(s):  
S. SAHA ◽  
S. N. BORA
Keyword(s):  
Surface Tension ◽  
Free Surface ◽  
Circular Cylinder ◽  
Boundary Value Problems ◽  
Finite Depth ◽  
Trapped Modes ◽  
Trapped Waves ◽  
Linearized Theory ◽  
Horizontal Circular Cylinder ◽  
Effect Of Surface

We consider a two-layer fluid of finite depth with a free surface and, in particular, the surface tension at the free surface and the interface. The usual assumptions of a linearized theory are considered. The objective of this work is to analyse the effect of surface tension on trapped modes, when a horizontal circular cylinder is submerged in either of the layers of a two-layer fluid. By setting up boundary value problems for both of the layers, we find the frequencies for which trapped waves exist. Then, we numerically analyse the effect of variation of surface tension parameters on the trapped modes, and conclude that realistic changes in surface tension do not have a significant effect on the frequencies of these.

Sign in / Sign up

Export Citation Format

Share Document