Abstract:
The main objective of this thesis was to ascertain and to catalogue the possible sources
of errors in the finite element method when used for fluid modelling. Some of these
errors are inherent in the finite element method whilst others are introduced by the user
when performing a fluid mechanical analysis. This thesis distinguishes from the two
and provides where possible, ways of preventing or controlling them.
The form is based on the SAFESA Technical manual, which is an equivalent for
structural analyses.
Focus is then made, as an example, on a real world problem; "The Backward Facing
Step" where, based on experimental data an element sensitivity analysis is performed
within ANSYS/FLOTRAN. This analysis attempts to determine the magnitude of errors
associated with prescribed element distortions in relation to aspect ratio, skew angle and
taper ratio.
The results contained within are in the form of graphical velocity profile plots, contour
plots and tables at the varying distortions. The results show a strong deviation from the
control mesh as the distortion is increased.