Experimental Measurements of the Natural Frequencies and Mode Shapes of Rotating Disk-Blades-Disk Assemblies from the Stationary Frame

• DOI: 10.3390/app9183864
• Publication Date: 2019-09-16T07:17:57Z
• Authors: Alexandre Presas; David Valentin; Carme Valero; Monica Egusquiza; Eduard Egusquiza
• Keywords: Turbomachinery; Centrifugal compressor

Determining the natural frequencies and mode shapes of rotating turbomachinery components from both stationary reference frames is paramount importance to avoid resonance problems that could affect normal operation machine, or even cause critical damages in these components. Due their similarity real engineering cases, this topic has been experimentally analyzed past for disk-shaft assemblies rotor disk-blades (bladed-disk blisk). The same less disk-blades-disk assemblies, although such configurations are widely used centrifugal closed impellers compressors, hydraulic pumps, pump-turbines, runners high head Francis turbines. In paper, experimental measurements, varying speed a disk-blade-disk assembly exciting first frame, have performed. structure excited measured by means PZT patches frame with Laser Doppler Vibrometer (LDV). order interpret results obtained method decompose diametrical simple (which define disk) proposed. It concluded resonant detected sensor correspond ones predicted decomposition method. Finally, obtain equivalent numerical simulation methods shown.