The paper investigates the formation of spurious vortical structures in inc
ompressible flow simulations employing Godunov-type methods. The present wo
rk is motivated by the earlier studies of Brown and Minion (1995, J. Comput
. Phys. 122, 165 and 1997, J. Comput, Phys. 138, 734) who demonstrated for
a variety of numerical schemes (and for the upwind-biased methods in partic
ular) that spurious vortices can occur in underresolved flow simulations. T
he aim of our work is threefold: (i) to identify deficiencies in various Go
dunov-type methods leading to spurious flow structures, (ii) to examine the
numerical mechanisms responsible for these artifacts, and (iii) to propose
modifications of Godunov-type methods in order to recover the correct solu
tions even under insufficient grid resolution. Our results reveal that the
occurrence of spurious solutions depends strongly on the Godunov-type metho
d employed. We show that in addition to the dissipation properties of a sch
eme-emphasized by Brown and Minion-there are other factors that can also co
ntribute to numerical artifacts. These include a vortical instability arisi
ng from the numerical discretization of the advective terms in the primitiv
e variable formulation of the Navier-Stokes equations, the balance of dissi
pation among the different discretized terms in a Godunov-type method. as w
ell as order of accuracy of the interpolation used to discretize the wave-s
peed dependent term of the Godunov flux. (C) 2001 Academic Press.