Steady, viscous, free-surface flow on a rotating cylinder

1994 ◽  
Vol 272 ◽  
pp. 91-108 ◽  
Author(s):  
Erik B. Hansen ◽  
Mark A. Kelmanson
Keyword(s):  
Free Surface ◽  
Stokes Equations ◽  
Fluid Layer ◽  
Free Surface Flow ◽  
Rotating Cylinder ◽  
Surface Flow ◽  
Surface Velocity ◽  
Cylinder Surface ◽  
Stokes Approximation ◽  
Integral Equation Formulation

The commonly observed phenomenon of steady, viscous, free-surface flow on the outer surface of a rotating cylinder is investigated by means of an iterative, integral-equation formulation applied to the Stokes approximation of the Navier-Stokes equations. The method of solution places no restriction on the thickness of the fluid layer residing on the cylinder surface; indeed, results are presented for cases where the layer thickness is of the same order of magnitude as the cylinder radius.Free-surface profiles and free-surface velocity distributions are presented for a range of flow parameters. Where appropriate, comparisons are made with the results of thinfilm theory; excellent agreement is observed.For all film thicknesses and surface tensions, results show a high degree of symmetry about a horizontal axis even though the gravity field is vertical. A proof is presented that, for vanishing surface tension, this is a consequence of the Stokes approximation.

scholarly journals Free-surface flow in horizontally rotating cylinder: experiment and simulation

2016 ◽  
Vol 143 ◽  
pp. 012036
Author(s):  
J Bohacek ◽  
A Kharicha ◽  
A Ludwig ◽  
M Wu ◽  
A Paar ◽  
...  
Keyword(s):  
Free Surface ◽  
Free Surface Flow ◽  
Rotating Cylinder ◽  
Surface Flow ◽  
Experiment And Simulation

scholarly journals On the behavior of nonlinear hydrodynamic coefficients of a submerged cylinder beneath the water surface

2021 ◽  
Author(s):  
Nguyen Van My ◽  
Le Anh Tien ◽  
Phan Hoang Nam ◽  
Nguyen Quoc Khanh ◽  
Chau Van Than ◽  
...  
Keyword(s):  
Free Surface ◽  
State Diagram ◽  
Free Surface Flow ◽  
Flow Fields ◽  
Horizontal Cylinder ◽  
Surface Flow ◽  
Navier Stokes ◽  
Cylinder Surface ◽  
Hydrodynamic Coefficients ◽  
Submerged Cylinder

This study aims at numerically exploring the behavior of flow fields and nonlinear hydrodynamic coefficients of a horizontal cylinder beneath the free surface flow considering the effects of nonlinear surface waves and various cylinder shapes. The computational model is based on two-dimensional incompressible Navier-Stokes solvers along with the treatment of the free surface flow using the volume of fluid method. The effect of the turbulent flow is also considered by using the shear stress transport turbulence model. The simulation result of a benchmark case study of the submerged cylinder is first validated with available experiment data, where a mesh convergence analysis is also performed. Afterward, the flow fields and hydrodynamic force coefficients around the cylinder surface are analyzed, and the influences of various cylinder shapes and Reynolds numbers on the hydrodynamic coefficients are investigated. A state diagram representing the hydrodynamic behavior including stable and unstable stages is finally proposed; this is an important criterion for the practice design of submerged civil structures under the free surface flow.

Free Surface Flow Past Ships in Shallow Water

2002 ◽  
Author(s):  
A. Ganguly ◽  
V. Shigunov ◽  
O. Turan
Keyword(s):  
Free Surface ◽  
Stokes Equations ◽  
Near Field ◽  
Free Surface Flow ◽  
Steady State Solution ◽  
Surface Flow ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Medium Speed ◽  
Measured Resistance

A finite volume method with a multiphase type free surface description is employed to calculate the flow around ships in shallow and restricted channels. The flows at critical and supercritical depth Froude numbers (Fnd = 1.0 and Fnd = 1.18) are calculated for Series–60 monohull and a medium speed catamaran. A steady state solution for Reynolds-averaged Navier-Stokes equations with a k-ε turbulence model is obtained by time marching. Computed wave profiles are in good agreement with model tests in the near field of the ship. The computed and measured resistance agree fairly well.

Numerical Simulation of Free Surface Flows Using STACS-VOF Method

2007 ◽  
Author(s):  
Vedanth Srinivasan ◽  
De Ming Wang
Keyword(s):  
Free Surface ◽  
Stokes Equations ◽  
Current Method ◽  
Coupled System ◽  
Free Surface Flow ◽  
Surface Force ◽  
Free Surface Flows ◽  
Surface Flow ◽  
Air Entrapment ◽  
Simple Strategy

This paper presents a numerical method that couples the incompressible Navier-Stokes equations with the Volume of Fluid method in a Cartesian co-ordinate system for tracking immiscible interfaces in multiple dimensions. The governing equations are discretized based on a finite volume method on a non-staggered fixed grid. The free surface flow problem is solved as a single phase flow system in which the free surface is captured using a Switching Technique for Advection and Capturing of Surfaces (STACS) scheme. The effects of surface tension at the interfaces are treated using a Continuum Surface Force (CSF) model. The pressure velocity coupling is achieved using a SIMPLE strategy. The coupled system, implemented in the commercial CFD software, AVL FIRE/SWIFT, is applied to a two dimensional dam breaking problem. The simulation results reveal a multitude of phenomena such as, free surface vortex generation, air entrapment and splashing of the liquid surge front. The computational results are in good agreement with experimental data, wherever available. The effects of time and grid resolution on the solution behavior are elaborated in detail. Different convection schemes are tested and the current method is compared to another existing interface capturing methodology.

scholarly journals Photogrammetry for Free Surface Flow Velocity Measurement: From Laboratory to Field Measurements

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1675
Author(s):  
Hang Trieu ◽  
Per Bergström ◽  
Mikael Sjödahl ◽  
J. Gunnar I. Hellström ◽  
Patrik Andreasson ◽  
...  
Keyword(s):  
Free Surface ◽  
Particle Tracking ◽  
Field Measurements ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Hydropower Plant ◽  
Surface Velocity ◽  
Camera System ◽  
Particle Tracking Method ◽  
Calibration Methods

This study describes a multi-camera photogrammetric approach to measure the 3D velocity of free surface flow. The properties of the camera system and particle tracking velocimetry (PTV) algorithm were first investigated in a measurement of a laboratory open channel flow to prepare for field measurements. The in situ camera calibration methods corresponding to the two measurement situations were applied to mitigate the instability of the camera mechanism and camera geometry. There are two photogrammetry-based PTV algorithms presented in this study regarding different types of surface particles employed on the water flow. While the first algorithm uses the particle tracking method applied for individual particles, the second algorithm is based on correlation-based particle clustering tracking applied for clusters of small size particles. In the laboratory, reference data are provided by particle image velocimetry (PIV) and laser Doppler velocimetry (LDV). The differences in velocities measured by photogrammetry and PIV, photogrammetry and LDV are 0.1% and 3.6%, respectively. At a natural river, the change of discharges between two measurement times is found to be 15%, and the corresponding value reported regarding mass flow through a nearby hydropower plant is 20%. The outcomes reveal that the method can provide a reliable estimation of 3D surface velocity with sufficient accuracy.

A Stable Semi-Implicit Method for Free Surface Flows

2005 ◽  
Vol 73 (6) ◽  
pp. 940-947 ◽  
Author(s):  
Cassio M. Oishi ◽  
José A. Cuminato ◽  
Valdemir G. Ferreira ◽  
Murilo F. Tomé ◽  
Antonio Castelo ◽  
...  
Keyword(s):  
Free Surface ◽  
Boundary Conditions ◽  
Stokes Equations ◽  
Free Surface Flow ◽  
Free Surface Flows ◽  
Surface Flow ◽  
Navier Stokes ◽  
Variable Order ◽  
Implicit Methods ◽  
Time Lagged

The present work is concerned with a semi-implicit modification of the GENSMAC method for solving the two-dimensional time-dependent incompressible Navier-Stokes equations in primitive variables formulation with a free surface. A projection method is employed to uncouple the velocity components and pressure, thus allowing the solution of each variable separately (a segregated approach). The viscous terms are treated by the implicit backward method in time and a centered second order method in space, and the nonlinear convection terms are explicitly approximated by the high order upwind variable-order nonoscillatory scheme method in space. The boundary conditions at the free surface couple the otherwise segregated velocity and pressure fields. The present work proposes a method that allows the segregated solution of free surface flow problems to be computed by semi-implicit schemes that preserve the stability conditions of the related coupled semi-implicit scheme. The numerical method is applied to both the simulation of free surface and to confined flows. The numerical results demonstrate that the present technique eliminates the parabolic stability restriction required by the original explicit GENSMAC method, and also found in segregated semi-implicit methods with time-lagged boundary conditions. For low Reynolds number flows, the method is robust and very efficient when compared to the original GENSMAC method.

Measurements of the Free Surface Flow Structure Under an Impinging, Free Liquid Jet

1992 ◽  
Vol 114 (1) ◽  
pp. 79-84 ◽  
Author(s):  
J. Stevens ◽  
B. W. Webb
Keyword(s):  
Free Surface ◽  
Flow Structure ◽  
Liquid Layer ◽  
Free Surface Flow ◽  
Reynolds Numbers ◽  
Surface Flow ◽  
Surface Velocity ◽  
Liquid Jet ◽  
Radial Coordinate ◽  
Measured Velocity

The objective of this research was to characterize the flow structure under an impinging liquid jet striking a flat, normally oriented surface. The approach was the measurement of the free surface velocities of the jet prior to impingement and the surface velocities of the radially spreading liquid layer. A novel laser-Doppler velocimetry technique was used. The LDV system was configured such that the measurement volume would span the time-dependent fluctuations of the free surface, with the surface velocity being measured. The mean and fluctuating components of a single direction of the velocity vector were measured. It was found that the radial liquid layer data collapsed well over the range of jet Reynolds numbers 16,000 < Re < 47,000 if plotted in dimensionless coordinates, where the measured velocity was normalized by the average jet exit velocity and the radial coordinate was normalized by the nozzle diameter. Mean liquid layer depths were inferred from the velocity measurements by assuming a velocity profile across the layer, and were reported. Pre-impingement jet measurements suggest that the flow development is nearly complete two diameters from the nozzle exit.

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