Gregor Cvijetić

Research Assistant, PhD student

University of Zagreb

Faculty of Mechanical Engineering and Naval Architecture

Department of Energy, Power Engineering and Environment

Chair of Turbomachinery

e-mail: gregor.cvijetic@fsb.hr

CFD Interests

Harmonic Balance method, turbomachinery simulations, compressible flow

PhD Thesis

Harmonic balance and time-periodic simulations in turbomachinery

Periodic flows are common in scientific and industrial studies such as rotating machinery, wave-like phenomena, various flows induced by periodic boundary conditions and different periodic body motions (wing oscillations, moving valves, etc.). For such problems transient simulations are mostly used, yielding long CPU time. In order to obtain periodic results and neglect initial transients, a number of periods need to be simulated. The need for reducing CPU time, but still preserving periodic flow features motivated the development of new methods. Harmonic Balance is such a method, developed specially for periodic problems with prescribed harmonic motion. As opposed to conventional steady state methods, the benefit of Harmonic Balance is the ability of capturing transient flow features, but at a cost of longer CPU time. However, compared to conventional transient simulation Harmonic Balance offers a significant CPU time reduction with comparable accuracy.

Supervisor: prof. Hrvoje Jasak