Fluid–structure interaction analysis of flexible turbomachinery

• Published in: Journal of fluids and structures 2011-11, Vol.27 (8), p.1376-1391
• Main Authors: Campbell, R.L., Paterson, E.G.
• Format: Article
• Language: English
• Subjects: Applied sciences; Computation; Computational fluid dynamics; Computer simulation; Deformation; Exact sciences and technology; Expandable pump; Fluid flow; Fluids; Fluid–structure interaction; Fundamental areas of phenomenology (including applications); Mechanical engineering. Machine design; Physics; Precision engineering, watch making; Pump and compressors (turbocompressors, fans, etc.); Solid mechanics; Solvers; Stress relaxation; Structural and continuum mechanics; Turbomachinery; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Viscoelasticity
• ISSN: 0889-9746; 1095-8622
• DOI: 10.1016/j.jfluidstructs.2011.08.010

A method for the performance computation of an expandable-impeller pump is developed and validated. Large deformations of the highly flexible pump impellers result in a strong coupling between the impeller and fluid flow. The computational method therefore requires simultaneous solution of fluid flow and structural response. OpenFOAM provides the flow and mesh motion solvers and is coupled to an author-developed structural solver in a tightly coupled approach using a fixed-point iteration. The structural deformations are time-dependent because the material exhibits stress relaxation. The time-constant of the relaxation, however, is very large, thereby allowing quasi-steady simulations. A water-tunnel test of a viscoelastic hydrofoil is employed to validate the solver. Simulations of the test problem show good agreement with the experimental results and demonstrate the need for several sub-iterations of the solver even for the quasi-steady simulations.