#
Introduction

The test case comprises a 2-D section comprising extruded triangle cells. An initial field is assigned the mesh cell centre values such that the computed gradient should take the value of 1 in each co-ordinate direction. By changing the choice of gradient scheme we can observe how each performs.

#
Case set-up

Gradient schemes under test:

- Gauss linear
- Gauss pointLinear
- leastSquares

Interpolation schemes under test:

##
Boundary conditions

Only the left and right domain boundaries are set to physical patch types; the remainder are set to the empty constraint to enforce the 2-D system.

##
Mesh

The mesh comprises extruded triangle cells with low non-orthogonality with average and maximum values of 7 and 26 deg, respectively.

##
Scheme controls

grad(Cc) <scheme>

#
Results

The following images show the percentage error of the magnitude of the gradient of the cell centres, defined as:

\[
\textrm{error} = 100 \frac{\left|\grad(C_c)\right| - 2^{0.5}}{2^{0.5}}
\]

The range is set to +/- 10% for all images.

##
Unlimited

##
Cell limited

##
Face limited

##
Multi-directional cell limited

##
Multi-directional face limited

Copyright © 2016 OpenCFD Ltd.

Licensed under the Creative Commons License BY-NC-ND