6,298 research outputs found
Numerical Solutions of 2-D Steady Incompressible Driven Cavity Flow at High Reynolds Numbers
Numerical calculations of the 2-D steady incompressible driven cavity flow
are presented. The Navier-Stokes equations in streamfunction and vorticity
formulation are solved numerically using a fine uniform grid mesh of 601x601.
The steady driven cavity solutions are computed for Re<21,000 with a maximum
absolute residuals of the governing equations that were less than 10-10. A new
quaternary vortex at the bottom left corner and a new tertiary vortex at the
top left corner of the cavity are observed in the flow field as the Reynolds
number increases. Detailed results are presented and comparisons are made with
benchmark solutions found in the literature
Discussions on Driven Cavity Flow
The widely studied benchmark problem, 2-D driven cavity flow problem is
discussed in details in terms of physical and mathematical and also numerical
aspects. A very brief literature survey on studies on the driven cavity flow is
given. Based on the several numerical and experimental studies, the fact of the
matter is, above moderate Reynolds numbers physically the flow in a driven
cavity is not two-dimensional. However there exist numerical solutions for 2-D
driven cavity flow at high Reynolds numbers
Fine Grid Numerical Solutions of Triangular Cavity Flow
Numerical solutions of 2-D steady incompressible flow inside a triangular
cavity are presented. For the purpose of comparing our results with several
different triangular cavity studies with different triangle geometries, a
general triangle mapped onto a computational domain is considered. The
Navier-Stokes equations in general curvilinear coordinates in streamfunction
and vorticity formulation are numerically solved. Using a very fine grid mesh,
the triangular cavity flow is solved for high Reynolds numbers. The results are
compared with the numerical solutions found in the literature and also with
analytical solutions as well. Detailed results are presented
Three-dimensional flow instability in a lid-driven isosceles triangular cavity
Linear three-dimensional modal instability of steady laminar two-dimensional states developing in a lid-driven cavity of isosceles triangular cross-section is investigated theoretically and experimentally for the case in which the equal sides form a rectangular corner. An asymmetric steady two-dimensional motion is driven by the steady motion of one of the equal sides. If the side moves away from the rectangular corner, a stationary three-dimensional instability is found. If the motion is directed towards the corner, the instability is oscillatory. The respective critical Reynolds numbers are identified both theoretically and experimentally. The neutral curves pertinent to the two configurations and the properties of the respective leading eigenmodes are documented and analogies to instabilities in rectangular lid-driven cavities are discussed
Numerical Solutions of 2-D Steady Incompressible Flow in a Driven Skewed Cavity
The benchmark test case for non-orthogonal grid mesh, the "driven skewed
cavity flow", first introduced by Demirdzic et al. (1992, IJNMF, 15, 329) for
skew angles of alpha=30 and alpha=45, is reintroduced with a more variety of
skew angles. The benchmark problem has non-orthogonal, skewed grid mesh with
skew angle (alpha). The governing 2-D steady incompressible Navier-Stokes
equations in general curvilinear coordinates are solved for the solution of
driven skewed cavity flow with non-orthogonal grid mesh using a numerical
method which is efficient and stable even at extreme skew angles. Highly
accurate numerical solutions of the driven skewed cavity flow, solved using a
fine grid (512x512) mesh, are presented for Reynolds number of 100 and 1000 for
skew angles ranging between 15<alpha<165
Comparison of Wide and Compact Fourth Order Formulations of the Navier-Stokes Equations
In this study the numerical performances of wide and compact fourth order
formulation of the steady 2-D incompressible Navier-Stokes equations will be
investigated and compared with each other. The benchmark driven cavity flow
problem will be solved using both wide and compact fourth order formulations
and the numerical performances of both formulations will be presented and also
the advantages and disadvantages of both formulations will be discussed
Three-dimensional flow in cavity with elevated helicity driven by parallel walls
The proposed flow in a 3-D cubic cavity is driven by its parallel walls
moving in perpendicular directions to create a genuinely three-dimensional
highly separated vortical flow yet having simple single-block cubical geometry
of computational domain. The elevated level of helicity is caused by motion of
a wall in the direction of axis of primary vortex created by a parallel wall.
The velocity vector field is obtained numerically by using second-order upwind
scheme and 200^3 grid. Helicity, magnitude of normalized helicity and kinematic
vorticity number are evaluated for Reynolds numbers ranging from 100 to 1000.
Formation of two primary vortices with their axis oriented perpendicularly and
patterns of secondary vortices are discussed. Computational results are
compared to the well-known 3-D recirculating cavity flow case where the lid
moves in the direction parallel to the cavity side walls. Also results are
compared to the diagonally top-driven cavity and to cavity flow driven by
moving top and side walls. The streamlines for the proposed flow show that the
particles emerging from top and bottom of cavity do mix well. Quantitative
evaluation of mixing of two fluids in the proposed cavity flow confirms that
the mixing occurs faster than in the benchmark case.Comment: 38 pages, 13 figures The revised includes quantification of mixing
rate; numerical modeling of the transient version.The revised version has
four substantially improved figures and three new figures; number of
literature references increased from 26 to 4
An upwind-differencing scheme for the incompressible Navier-Stokes equations
The steady state incompressible Navier-Stokes equations in 2-D are solved numerically using the artificial compressibility formulation. The convective terms are upwind-differenced using a flux difference split approach that has uniformly high accuracy throughout the interior grid points. The viscous fluxes are differenced using second order accurate central differences. The numerical system of equations is solved using an implicit line relaxation scheme. Although the current study is limited to steady state problems, it is shown that this entire formulation can be used for solving unsteady problems. Characteristic boundary conditions are formulated and used in the solution procedure. The overall scheme is capable of being run at extremely large pseudotime steps, leading to fast convergence. Three test cases are presented to demonstrate the accuracy and robustness of the code. These are the flow in a square-driven cavity, flow over a backward facing step, and flow around a 2-D circular cylinder
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