Design Method of a Subsonic Aspirated Cascade

A direct two-dimensional method for designing subsonic aspirated cascades is presented in this paper. This approach implements a specific aspiration strategy by means of a novel prescribed-curvature blading model, based on classical differential geometry. The derivation of the blade shape from the curvature distributions of the suction and pressure sides is addressed, with particular emphasis on the key design features for an efficient design with aspiration. As an application, a subsonic aspirated stator cascade, producing a 60-degree flow turning for a diffusion factor of 0.73 is achieved, with 1.1% of the inlet mass flow removed. With this method, the aspirated mass flow rate to meet design requirements is almost insensitive of the inlet Mach number. On the other hand, the same mass flow rate is found to be strongly dependent on the inlet flow angle.