Hi, I am not sure what this might show. At lower Reynolds numbers we expect secondary instabilities to have arisen from Mode A or B secondary instabilities and so it is not clear to me that higher Reynolds number instabilities should derive from a periodic or phase averaged field rather than a fully three-dimensional, probably unsteady flow field. So I understand the onset can be capture with biglobal stability but that is at Lower Reynolds numbers. I do not understand what is the appropriate question at higher Reynolds numbers. Cheers, Spencer. On 19 Jan 2016, at 12:36, Hongfu Zhang <hongfu2233@gmail.com<mailto:hongfu2233@gmail.com>> wrote: Dear, Spencer At such high Re, there may exist a primary votex shedding frequency in wake of a bluff body. I take these flow fields in a shedding period as base flow (phase-average may be used if the wake is not strict time period). Do you think it is a right way to study the period wake instability (BiGlobal stability analysis)? Best Regards! Hongfu 2016-01-19 2:30 GMT+08:00 Sherwin, Spencer J <s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk>>: Dear Hongfu, This is theoretically possible. However the challenge I see behind your question is what you would take as an appropriate base flow? At such a high Reynolds number there are many different flow states and to perform stability analysis you have to have an appropriate base flow. Cheers, Spencer. On 18 Jan 2016, at 01:24, Hongfu Zhang <hongfu2233@gmail.com<mailto:hongfu2233@gmail.com>> wrote: Dear, All I would like to know if the linear stability analysis (fully 3D stability or BiGlobal stability) could be used at high Re (such Re is about 10e5) for a bluff body such as square cylinder (external flow)? Regards! Hongfu. 2016-01-18 4:57 GMT+08:00 Sherwin, Spencer J <s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk>>: Dear Siddarth, We have been exploring this option, most recently in the work of Bastien Jordi under his thesis work. I am trying to get hold of a digital copy or Bastien can send you one. One of the challenges of doing fully 3D stability analysis is how to get hold of an appropriate base flow. Do you have a way to do this? Otherwise I think the tools are generally working although we are continuing to validate them. Regards, Spencer. On 16 Jan 2016, at 22:24, Siddarth Chintamani <siddarth.ch1990@gmail.com<mailto:siddarth.ch1990@gmail.com>> wrote: Hello, I am trying to perform stability analysis of linearized incompressible Navier Stokes equation of a three-dimensional baseflow. I understand that Nektar++ capabilities for stability analysis are limited to 2D or Quasi3D baseflow representation. Unfortunately, my problem has to be solved as 3D. Is there any way to relax the 2D or quasi3D representation? Any help will be greatly appreciated. Thank you, Siddarth Chintamani _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users Spencer Sherwin McLaren Racing/Royal Academy of Engineering Research Chair, Professor of Computational Fluid Mechanics, Department of Aeronautics, Imperial College London South Kensington Campus London SW7 2AZ s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk> +44 (0) 20 759 45052 _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users Spencer Sherwin McLaren Racing/Royal Academy of Engineering Research Chair, Professor of Computational Fluid Mechanics, Department of Aeronautics, Imperial College London South Kensington Campus London SW7 2AZ s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk> +44 (0) 20 759 45052 Spencer Sherwin McLaren Racing/Royal Academy of Engineering Research Chair, Professor of Computational Fluid Mechanics, Department of Aeronautics, Imperial College London South Kensington Campus London SW7 2AZ s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk> +44 (0) 20 759 45052