Skip to content

Research

CDIF develops applied research in Fluid Dynamics and Turbomachines.

Research is focused on fluid-structure interaction phenomena on simple geometries (as hydrofoils) and complex structures (as a turbomachine rotor).

The acquired knowledge is applied in the study of large scale pump-turbine power generation groups as the ones used for hydropower

The research includes the study of the dynamic excitations generated by the flow and the dynamic response of fixed (hydrofoils) or rotating (turbomachine rotor) structures to these excitations.

Dynamic response analysis of the structure is of paramount importance when designing slender structures or when the excitations’ magnitude can generate excessive vibration and stresses than can lead to a fatigue failure.

A turbomachine rotor is a complex structure submerged in water, rotating inside an enclosure with very small gaps between the enclosure and the vanes. Under these conditions, the added mass and damping effects influence the modal response of the structure, which generates uncertainties when estimating vibration modes, frequencies and amplitude of the vibration phenomena. On the other hand, with the trend of increasing power concentration in generation groups, the exciting forces over the rotor are becoming more intense, especially the forces generated by the rotor-stator interaction. Wake interaction and cavitation are also studied, as they also have a primal role in the excitation phenomena.


In order to develop the research the following techniques are used:


  • Transient flow numerical simulation (CFD) and structural response simulation (FEM). For complex study cases, high performance computation (HPC) is performed using the supercomputers of Catalonia’s Supercomputing Center (CESCA).
  • Experimentation in basic structures and reduced scale models (in collaboration with the Hydraulic Machines Laboratory (LMH)  of the Polytechnic Federal School of Lausanne, Switserland (EPFL).
  • Data gathering on real generation groups (ENDESA GENERACIÓN).
  • Signal analysis for vibration data.

 

The know-how and experience gathered over the years are applied to the simulation and anaylisis of the vibrational behavior in advance monitoring, damage diagnosis and predicitive maintenance.