  Molten metal melt pools are characterised by highly non-linear responses,
which are very sensitive to imposed boundary conditions. Temporal and spatial
variations in the energy flux distribution are often neglected in numerical
simulations of melt pool behaviour. Additionally, thermo-physical properties of
materials are commonly changed to achieve agreement between predicted melt-pool
shape and experimental post-solidification macrograph. Focusing on laser spot
melting in conduction mode, we investigated the influence of dynamically
adjusted energy flux distribution and changing thermo-physical material
properties on melt pool oscillatory behaviour using both deformable and
non-deformable assumptions for the gas-metal interface. Our results demonstrate
that adjusting the absorbed energy flux affects the oscillatory fluid flow
behaviour in the melt pool and consequently the predicted melt-pool shape and
size. We also show that changing the thermophysical material properties
artificially or using a non-deformable surface assumption lead to significant
differences in melt pool oscillatory behaviour compared to the cases in which
these assumptions are not made.
