Abstract

The instability of stationary vortex structures is manifested by an oscillation at several fundamental frequencies which are associated with characteristic shapes. It is caused by the non-linear convective terms in the Navier-Stokes equations. The frequency of unstable oscillation can be detected by the Fourier transform of the velocity and the pressure field themselves or their constitutive modes. It is this knowledge of the constitutive modes that is the basis for using the inverse method to define a reduced mathematical model in a finite-dimensional space. This model allows to analyze the vortex structures in the region of instability and their dependence on inhomogeneous boundary conditions. Present paper describes the essential steps of deriving an inverse method. The inverse method is applied to fluid flow in the draft tube of a swirl generator. The dynamic mode decomposition and the discrete Fourier transform of the flow field are assessed as possible methods that can provide the modal and spectral matrix for the model.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.