The prediction capabilities of a linearized unsteady potential analysis have been extended to include supersonic cascades with subsonic axial flow. The numerical analysis of this type of flow presents several difficulties. First, complex oblique shock patterns exist within the cascade passage. Second, the acoustic response is discontinuous and propagates upstream and downstream of the blade row. Finally, a numerical scheme based on the domain of dependence is required for numerical stability. These difficulties are addressed by developing a discontinuity capturing scheme and matching the numerical near-field solution to an analytical far-field solution. Comparisons with semi-analytic results for flat plate cascades show that reasonable predictions of the unsteady aerodynamic response at the airfoil surfaces are possible, but aeroacoustic response calculations are difficult. Comparisons between flat plate and real blade cascade results show that one effect of real blades is the impulsive loads due to motion of finite strength shocks.

The unsteady flow field generated by rotating rows of perforated plates and airfoil cascades is mathematically split into vortical and potential components using two methods, one relying entirely on velocity data and the other utilizing both velocity and unsteady static pressure data. The propagation and decay of these split flow perturbations are then examined and compared to linear theory predictions. The perforated plate gusts closely resemble linear theory vortical gusts. Both splitting methods indicate that they are dominantly vortical gusts with insignificant unsteady static pressure perturbations. The airfoil gusts resemble linear theory combined vortical and potential gusts. The recombined airfoil gusts using the vortical and potential components calculated by the method using only unsteady velocity data do not necessarily resemble the measured gusts, nor do they behave axially as predicted by linear theory. The recombined airfoil gusts using the linear theory components calculated by the method using both unsteady velocity and unsteady static pressure data do resemble the measured gusts and behave axially as predicted by linear theory, with the vortical component propagating unattenuated and the potential component decaying at the rate predicted by linear theory.