Prediction of flow patterns in scoured beds caused by submerged horizontal jets

2006 ◽  
Vol 33 (1) ◽  
pp. 41-48 ◽  
Author(s):  
M Gunal ◽  
A Guven
Keyword(s):  
Boundary Layer ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Experimental Studies ◽  
Simple Algorithm ◽  
Rectangular Domain ◽  
Two Dimensions ◽  
Staggered Grid ◽  
Mean Flow ◽  
Volume Method

The basic goal of this study is to present a numerical simulation model for turbulent water flow issued on frozen scoured beds. The model uses a finite volume method to solve the equations of motion and transport equations for two dimensions on a transformed rectangular domain using boundary-fitted coordinates. The internal characteristics of the mean flow of submerged horizontal jets including surface profiles on frozen scoured beds are computed by a two-dimensional k–ε turbulence model. Computations are carried out at different frozen-scoured bed profiles. A staggered grid system is adapted for variable arrangements to avoid the well-known checkerboard oscillations in pressure and velocity. The SIMPLE algorithm is adapted for the computation. No experimental studies were performed during this investigation. The diffusion characteristics of the submerged jet, growth of boundary layer thickness, velocity distribution within the boundary layer, and shear stress at the scour are investigated and compared with the results of others. Key words: boundary-fitted coordinates, local scour, k–ε model, finite volume method, horizontal jets, submerged jets.

scholarly journals An Unstructured Finite Volume Method for Incompressible Flows With Complex Immersed Boundaries

2009 ◽  
Author(s):  
Lin Sun ◽  
Sanjay R. Mathur ◽  
Jayathi Y. Murthy
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Incompressible Flows ◽  
Simple Algorithm ◽  
Flow Region ◽  
Solid Material ◽  
The Body ◽  
Immersed Boundary ◽  
Material Points ◽  
Volume Method

A numerical method is developed for solving the 3D, unsteady, incompressible flows with immersed moving solids of arbitrary geometrical complexity. A co-located (non-staggered) finite volume method is employed to solve the Navier-Stokes governing equations for flow region using arbitrary convex polyhedral meshes. The solid region is represented by a set of material points with known position and velocity. Faces in the flow region located in the immediate vicinity of the solid body are marked as immersed boundary (IB) faces. At every instant in time, the influence of the body on the flow is accounted for by reconstructing implicitly the velocity the IB faces from a stencil of fluid cells and solid material points. Specific numerical issues related to the non-staggered formulation are addressed, including the specification of face mass fluxes, and corrections to the continuity equation to ensure overall mass balance. Incorporation of this immersed boundary technique within the framework of the SIMPLE algorithm is described. Canonical test cases of laminar flow around stationary and moving spheres and cylinders are used to verify the implementation. Mesh convergence tests are carried out. The simulation results are shown to agree well with experiments for the case of micro-cantilevers vibrating in a viscous fluid.

scholarly journals Navier-Stokes Simulation of the MIT Flapping Foil Experiment Using an Unstructured Finite Volume Method

1999 ◽  
Author(s):  
Dong Jin Kang ◽  
Sang Soo Bae ◽  
Jae Won Kim
Keyword(s):  
Boundary Layer ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Local Minimum ◽  
Free Stream ◽  
Navier Stokes ◽  
Unsteady Boundary Layer ◽  
Flapping Foil ◽  
Volume Method ◽  
Unstructured Finite Volume Method

A Navier-Stokes simulation of the MIT flapping foil experiment is presented. The MIT experiment was designed to provide a good quality database for unsteady boundary layer flows. The unsteady boundary layer around a hydrofoil was generated by flapping two airfoils upstream of the hydrofoil. Present Navier-Stokes simulation is carried out on the entire experimental domain, including the flapping airfoils as well as the downstream fixed hydrofoil. Present Navier-Stokes code uses an unstructured finite volume method based on the SIMPLE algorithm. It uses QUICK scheme for the convective terms and the second order Euler backward differencing for time derivatives to keep second order accuracy spatially and temporally. All other spatial derivatives are approximated by using central difference scheme. All comparisons of present time averaged and unsteady solutions with the corresponding experimental data are satisfactory: all unsteady solutions are compared in terms of time mean and first harmonic. The first harmonic of the velocity shows a peak inside the boundary layer along the surfaces of the hydrofoil and has a local minimum near the edge of the boundary layer. The local minimum becomes manifest as the boundary layer grows. The unsteadiness in the free stream is transferred inside the boundary layer when an unsteady vortex impinges on the surface. The entrained unsteadiness travels with a local velocity slower than that in the free stream. This causes phase lag of the first harmonic between the free stream and the boundary layer and local minimum of the first harmonic near the edge of the boundary layer.

scholarly journals On Convergence of the Exponentially Fitted Finite Volume Method With an Anisotropic Mesh Refinement for a Singularly Perturbed Convection-diffusion Equation

2003 ◽  
Vol 3 (3) ◽  
pp. 493-512 ◽  
Author(s):  
Song Wang ◽  
Lutz Angermann
Keyword(s):  
Diffusion Equation ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Two Dimensions ◽  
Singularly Perturbed ◽  
Discrete Energy ◽  
Convection Diffusion ◽  
Convection Diffusion Equation ◽  
Exponentially Fitted ◽  
Volume Method

AbstractThis paper presents a convergence analysis for the exponentially fitted finite volume method in two dimensions applied to a linear singularly perturbed convection-diffusion equation with exponential boundary layers. The method is formulated as a nonconforming Petrov-Galerkin finite element method with an exponentially fitted trial space and a piecewise constant test space. The corresponding bilinear form is proved to be coercive with respect to a discrete energy norm. Numerical results are presented to verify the theoretical rates of convergence.

Three-Dimensional Finite-Volume Method for Incompressible Flows With Complex Boundaries

1992 ◽  
Vol 114 (4) ◽  
pp. 496-503 ◽  
Author(s):  
S. Majumdar ◽  
W. Rodi ◽  
J. Zhu
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Incompressible Flows ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Simple Algorithm ◽  
Computer Code ◽  
Laminar Flows ◽  
Vector Computers ◽  
Volume Method

A finite-volume method is presented for calculating incompressible 3-D flows with curved irregular boundaries. The method employs structured nonorthogonal grids, cell-centered variable arrangement, and Cartesian velocity components. A special interpolation procedure for evaluating the mass fluxes at the cell-faces is used to avoid the nonphysical oscillation of flow variables usually encountered with the cell-centered arrangement. The SIMPLE algorithm is used to handle the pressure-velocity coupling. A recently proposed low diffusive and bounded scheme is introduced to approximate the convection terms in the transport equations. The computer code and the relevant data structure are so organized that most of the code except the implicit linear solver used is fully vectorizable so as to exploit the potential of modern vector computers. The capabilities of the numerical procedure are demonstrated by application to a few internal and external three-dimensional laminar flows. In all cases the CPU-time on a grid with typically 28,000 grid nodes was below half a minute.

The Sweep Efficiency of Viscoelastic Polymer Solution

2013 ◽  
Vol 316-317 ◽  
pp. 975-978
Author(s):  
Hai Mei Jiang ◽  
Jin Qing Zhang ◽  
Shu Xu Zhang ◽  
Xiao Kang Sun
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Weissenberg Number ◽  
Staggered Grid ◽  
Viscoelastic Flows ◽  
Sweep Efficiency ◽  
Model Fluid ◽  
Stable Solutions ◽  
Volume Method ◽  
Main Factor

A finite volume method for the numerical solution of viscoelastic flows is presented in this paper. The flow of a differential upper-convected Maxwell (UCM) model fluid through an abrupt expansion has been chosen as a prototype example. The equations are solved using the finite volume method (FVM) in a staggered grid. Stable solutions are found for high Weissenberg number (We), further extending the range of simulations with the FVM. Numerical results show the viscoelasticity of polymer solutions is the main factor influencing sweep efficiency.

scholarly journals A Three-Dimensional, Immersed Boundary, Finite Volume Method for the Simulation of Incompressible Heat Transfer Flows around Complex Geometries

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Hassan Badreddine ◽  
Yohei Sato ◽  
Matthias Berger ◽  
Bojan Ničeno
Keyword(s):  
Heat Transfer ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Three Dimensional ◽  
Staggered Grid ◽  
Immersed Boundary ◽  
Convection Flow ◽  
Complex Geometries ◽  
Volume Method ◽  
Benchmark Solutions

The current work focuses on the development and application of a new finite volume immersed boundary method (IBM) to simulate three-dimensional fluid flows and heat transfer around complex geometries. First, the discretization of the governing equations based on the second-order finite volume method on Cartesian, structured, staggered grid is outlined, followed by the description of modifications which have to be applied to the discretized system once a body is immersed into the grid. To validate the new approach, the heat conduction equation with a source term is solved inside a cavity with an immersed body. The approach is then tested for a natural convection flow in a square cavity with and without circular cylinder for different Rayleigh numbers. The results computed with the present approach compare very well with the benchmark solutions. As a next step in the validation procedure, the method is tested for Direct Numerical Simulation (DNS) of a turbulent flow around a surface-mounted matrix of cubes. The results computed with the present method compare very well with Laser Doppler Anemometry (LDA) measurements of the same case, showing that the method can be used for scale-resolving simulations of turbulence as well.

Sign in / Sign up

Export Citation Format

Share Document