The Nonlinear Harmonic module
Gain 2 to 3 orders of magnitude in solving speed for unsteady simulation.
The Nonlinear Harmonic method can be used on both single or multi-stage turbomachinery configurations and allows a significant speed-up for unsteady analysis leading to a CPU gain of 2 to 3 orders of magnitude compared to full-unsteady simulations.
It decomposes the unsteady flow variables into time-averaged variables and periodic unsteady perturbations.
This unique technique computes the unsteady flow field by means of the Fourier decomposition of the periodic fluctuations based on a pre-selected number of harmonics, typically associated with the blade passing frequencies of the turbomachinery configuration and their multiples.
It also provides the full unsteady flow field predictions for the selected harmonics. Furthermore, because of the transposition to the frequency domain, only one blade channel is required.