分野別セミナー

In this seminar, study on the development of the stability analysis method of compressible flow is reported. Compressible flow is a complex flow involving sound propagation and changes of internal energy. Thus, the effect of compressibility on incompressible vortex dynamics is an essential problem. In this research, we investigated the compressibility effect on incompressible steady and unsteady vortex movement using global stability analysis. The calculation results show the layer distribution around velocity shear layer and mode separation of vortex and sound propagation especially for low Mach number. In the latter section of this seminar, we report the development of novel stability analysis based on estimated orbital stability as an extension of nonlinear global optimal disturbance method. In this analysis, the entropy production relating to orbital stability is focused on and the calculation results of flow around a 2D square cylinder are presented.