In the numerical computations of flows, errors can arise because of inadequate turbulence models and/or incorrect empirical constants in addition to an improper finite-difference formulation of the governing equations. The considered investigation illustrates one type of numerical error. In the calculation of axisymmetric flows, the centerline can be formulated in two different manners. According to one approach, the governing equations are expressed as limiting forms on the centerline. According to the second approach, appropriate finite-difference equations are found by integrating over the grid interval. It is shown that for compressible flows and certain types of effective viscosity models, the use of a limiting form of the governing equations can lead to significant errors in the results.