Gregor Cvijetić presents at AIAA SciTech Forum in Florida

Gregor Cvijetić has presented his work on Compressible Harmonic Balance Method for Turbomachinery at AIAA SciTech Forum held in Gaylord Palms, Kissimmee, Florida.

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Recent developments in the Harmonic Balance method for compressible turbomachinery simulations are presented in this paper. The Harmonic Balance method is based on the Fourier series decomposition for the solution variable. By doing this, the transformation from a single transient problem to a small number of coupled steady state snapshots is achieved. Depending on the number of harmonics in the Fourier series, n, a set of 2n + 1 coupled equations is assembled, yielding the solution for the whole representative period. The method is implemented in the Finite Volume framework within the open source software foam-extend, a community driven fork of OpenFOAM. The method is designed for turbomachinery use, based on segregated pressure-based solution methodology. The 1.5 stage turbine test case is presented in the paper, demonstrating the Harmonic Balance capabilities for compressible flow. Since dominant frequencies of rotor and stator are not the same, spatially varying multiple-frequency approach is used, yielding different frequency spectra for the rotor and stator. The Harmonic Balance method with different number of harmonics is validated against a compressible steady state MRF simulation.