  The problem of determining the pattern of gas motions in the central cases --
noncircular motions in the triaxial bar potential and motions in circular
orbits but with orientation parameters different from those of the main disk --
are shown to have similar observational manifestations in the line-of-sight
velocity field of the gas. A reliable criterion is needed fo the observational
data to be properly interpreted. To find such a criterion, we analyze
two-dimensional nonlinear hydrodynamics models of gas motions in barred disk
galaxies. The gas line-of-sight velocity and surface brightness distributions
in the plane of the sky are constructed for various inclinations of the
galactic plane to the line-of-sight and bar orientation angles. We show that
using models of circular motions for inclinations $i > 60^\circ$ to analyze the
velocity field can lead to the erroneous conclusions of a ``tilted (polar)
disk'' at the circumnuclear region. However, it is possible to distinguish bars
from tilted disks by comparing the mutual orientations of the photometric and
dynamical axes. As an example, we consider the velocity field of the ionized
gas in the galaxy NGC 972.
