******************* This email originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list https://spam.ic.ac.uk/SpamConsole/Senders.aspx to disable email stamping for this address. ******************* Dear Sir or Madam, I have two questions when using transient analysis: 1. The transient growth analysis in Nektar++ is only useful for steady or periodic base flow, right? 2. The CFL when processing the backward equation maybe much large. Is it OK for linearised operator? Regards Gong
Hi Gong, We have applied the transient growth to non periodic base flows by interpolating snapshots. I am cc’ing Ankang who can confirm if the interpolation feature is in the master branch or a separate branch currently. Since we use an explicit in time discretisation for the advection term which will depend on the same base flow as the forward problem I suspect you will need a similar CFL condition. I have however not investigated this. Cheers, Spencer. On 16 Jul 2021, at 03:40, gongminjiang@hrbeu.edu.cn<mailto:gongminjiang@hrbeu.edu.cn> wrote: This email from gongminjiang@hrbeu.edu.cn<mailto:gongminjiang@hrbeu.edu.cn> originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list<https://spam.ic.ac.uk/SpamConsole/Senders.aspx> to disable email stamping for this address. Dear Sir or Madam, I have two questions when using transient analysis: 1. The transient growth analysis in Nektar++ is only useful for steady or periodic base flow, right? 2. The CFL when processing the backward equation maybe much large. Is it OK for linearised operator? Regards Gong _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
Hi Spencer and Gong, The interpolation of non-periodic base flows has been merged into the master branch in commit aaa8f7eb. Cheers Ankang ________________________________ From: Sherwin, Spencer J <s.sherwin@imperial.ac.uk> Sent: 16 July 2021 08:34 To: gongminjiang@hrbeu.edu.cn <gongminjiang@hrbeu.edu.cn> Cc: nektar-users <nektar-users@imperial.ac.uk>; Gao, Ankang <ankang.gao@imperial.ac.uk> Subject: Re: [Nektar-users] Transient Growth Analysis Hi Gong, We have applied the transient growth to non periodic base flows by interpolating snapshots. I am cc’ing Ankang who can confirm if the interpolation feature is in the master branch or a separate branch currently. Since we use an explicit in time discretisation for the advection term which will depend on the same base flow as the forward problem I suspect you will need a similar CFL condition. I have however not investigated this. Cheers, Spencer. On 16 Jul 2021, at 03:40, gongminjiang@hrbeu.edu.cn<mailto:gongminjiang@hrbeu.edu.cn> wrote: This email from gongminjiang@hrbeu.edu.cn<mailto:gongminjiang@hrbeu.edu.cn> originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list<https://spam.ic.ac.uk/SpamConsole/Senders.aspx> to disable email stamping for this address. Dear Sir or Madam, I have two questions when using transient analysis: 1. The transient growth analysis in Nektar++ is only useful for steady or periodic base flow, right? 2. The CFL when processing the backward equation maybe much large. Is it OK for linearised operator? Regards Gong _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
participants (3)
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Gao, Ankang
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gongminjiang＠hrbeu.edu.cn
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Sherwin, Spencer J