Research Information System
International Congress of Theoretical and Applied Mechanics, 26 - 28 August 2020, pp.1, (Summary Text)
The effect of a variable transformation on the linear operator that is obtained by linearizing a turbulent flow about its mean is investigated. It is shown that the characteristics of the linear operator are dependent on the state variables used and can be modified when the state vector is subjected to non-linear transformation and linearisation is not performed around a fixed point. This observation raises a uniqueness issue for mean-flow resolvent analyses. The effect of the variable transformation on the stability characteristics is demonstrated via some test cases, including a subsonic jet. The implications for the validity of mean-flow resolvent analyses and possibilities for optimizing resolvent-based approaches are discussed.