Spectral Multi-Domain Methods for BiGlobal Instability Analysis of Complex Flows over Open Cavity Configurations

The potential geometric complexity of a full-bay open cavity configuration calls for the development of novel numerical methods which permit addressing the appropriate linear instability problem in the open cavity. Here results are reported of the first-ever non-conforming spectral multidomain approach for the numerical solution for the twodimensional BiGlobal eigenvalue problem. Analytical model problems 1 and the linear BiGlobal instability of the lid-driven cavity 2 have been used to validate the developed algorithms. New results have been obtained in open cavities of variable aspect ratio, both empty and in the presence of a model store, and the strong dierences of the respective eigenspectra has been documented. The latter result should serve as guidance for theoretical/numerical eorts aiming at flow control of full-bay configurations, using potentially restictive instability analysis models which neglect the presence of stores in the cavity.