Effects of a Single Blade Incidence Angle Offset on Adjacent Blades in a Linear Cascade

Abstract

The paper presents a numerical and experimental investigation of the effect of incindence angle offset in a two-dimensional section of a flat blade cascade in a high-speed wind tunnel. The aim of the current work is tp determine the aerodynamic excitation forces and approximation of the unsteady blade-loading function using a quasi-stationary approach. The numerical simulations were performed with an in-house finite-volume code built on the top of the OpenFOAM framework. The experimental data were acquired for regimes corresponding to the numerical setup. The comparison of the computational and experimental results is shown for the static pressure distributions on three blades and upstream and downstream of the cascade. The plot of the aerodynamic moments acting on all five blades shows that the adjacent blades are significantly influenced by the angular offset of the middle blade.

Aerodynamic and dynamic loading in a blade cascade designed for flutter research

“…The middle blade is driven by a high-speed electric motor and can be either fixed with a specific incidence angle, or undergo forced torsional oscillation with amplitudes 1 − 3 deg and frequencies up to 200 Hz. More details can be found in [3,4].…”

“…Building on previous experience with the NASA Transonic Flutter Cascade [2], a new experimental setup for controlled flutter testing has been designed in cooperation of the Institute of Thermomechanics of the Czech Academy of Sciences and Faculty of Mechatronics of the Technical University of Liberec during last two years [3]. Together with numerical simulations [4], the setup will serve for investigation of the aerodynamic and structural conditions leading to this dangerous aeroelastic phenomenon. The current contribution reports on first measurements of the pressure distribution, aerodynamic moments and deformation of the middle blade due to inertial loads during high-frequency oscillation.…”

Flutter Measurement of a Linear Turbine Blade Cascade with an Angular Position Deviation of One Blade

“…The experimental setup is often used to produce test data for validation of numerical methods; see examples in [27][28][29]. This paper, similarly to the work [30], reports only the initial results of the ongoing research and the findings are already important as no flutter investigation of a linear turbine blade cascade with blade position deviations is presented in the literature.…”