The modular compressor at the Transonic Compressor Darmstadt test facility at Technical University of Darmstadt enables investigations of prototype BLISK rotors in single or 1.5-stage setups, operating at high-speed conditions. Within the framework of the European funded research project ARiAS (Advanced Research into Aeromechanical Solutions), forced response blade vibration phenomena and underlying fluid-structure-interaction are investigated. For this, the Darmstadt Open Test Case is enhanced with new rig hardware and equipped with additional steady and unsteady instrumentation to perform extensive aerodynamic and aeromechanical tests. To excite a distinct engine order, a variable wake generator module is applied upstream the rotor BLISK containing 3–16 equally spaced symmetric NACA airfoils. One goal is to experimentally characterize the resulting flow features and determine the impact of wake forcing and rotor tip-clearance on blade vibration and aero-damping by performing a parameter study of various configurations and operating conditions. This paper comprises an overview of the ARiAS compressor stage setup, applied instrumentation and performed measurements. It emphasizes the substantial aerodynamic variations induced by different excitation features, while simultaneously highlighting the inherent independence of the measured system damping from these variations across three fundamental resonance crossings.

An experiment-supported simulation process chain is set up to perform numerical forced response analyses on a transonic high-pressure compressor front stage at varying operating conditions. A wake generator is used upstream of the rotor to excite a specific resonance within the operating range of the compressor. Thereby, extensive aerodynamic and structural dynamic experimental data, obtained from state-of-the-art rig testing at the Transonic Compressor Darmstadt test facility at the Technical University of Darmstadt, are used to validate numerical results and ensure realistic boundary conditions. In the course of this, five-hole-probe measurements at steady operating conditions close to the investigated resonance enable a validation of the steady aerodynamics. Subsequently, numerically obtained aeroelastic quantities, such as resonance frequency, and damping, as well as maximum alternating blade stresses and tip deflections, are compared to experimental blade tip timing data. Experimental trends in damping can be confirmed and better explained by considering numerical results regarding the aerodynamic wall work density and secondary flow phenomena. The influence of varying loading conditions on the resonance frequency is not observed as distinctly in numerical, as in experimental results. Generally, alternating blade stresses and deflections appear to be significantly lower than in the experiments. However, similar to the aerodynamic damping, numerical results contribute to a better understanding of experimental trends. The successive experimental validation shows the capabilities of the numerical forced response analysis setup and enables the highlighting of challenges and identification of potential further adaptations.