Numerical Investigation on the Pressure Perturbation of a Transonic Aeroelastic Compressor Rig

Abstract

A linear aeroelastic rig was designed to serve as a validation facility for forced response research in axial compressors. This rig focuses on the study of aerodynamic damping at high-reduced frequencies when the central blade oscillates in a controlled manner. The steady and unsteady flow field of the rig has been numerically investigated previously. This paper aims to understand the pressure perturbation throughout the domain, which will give more insight into the actual transonic linear cascade rig and will improve the design of the test rig in some aspects. Such aspects are the tip gaps of the side blades that with the previously optimized upper inclined wall and tailboards are of importance in keeping flow periodicity. The design process has shown that these components do influence the unsteady pressure distribution, which might reduce the accuracy of the experiments. Thus, the aeroelastic cascade itself needs detailed investigations on the systematic accuracy losses in the unsteady testing due to the current design layout. This paper presents the impacts and mechanisms of tip gaps, upper inclined wall, and bottom tailboard on the test rig's aeroelastic performance. It provides a new validation reference for cascade test results with a perspective on the numerical studies, which can introduce a correction procedure on the existing test rig or on future cascade designs.

A Three-Dimensional Design to Study the Shock Waves of Linear Cascade with Reduced Mass Flow Requirements

“…Their investigation specifically focused on a transonic cascade and revealed that unsteady pressure reflections on the tailboards play a significant role and must be taken into account during wind tunnel testing. Furthermore, the bottom tailboard was found to cause more pronounced unsteady reflections compared to the upper tailboard [4]. This finding highlights the importance of considering the specific characteristics and effects of each tailboard to accurately analyze fluid flow periodicity in transonic/supersonic cascades [5][6][7][8].…”