******************* 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 users, I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++. I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?). I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too. Many thanks, Dr. Ed Threlfall (UKAEA).
Dear Edward, For Rayleigh-Benard convection, a BodyForce function is applied for the buoyancy term. Presently, it works perfectly with Nektar 4.5, but there is some issue in Nektar 5 for this function. I have attached a xml file, which solves the Rayleigh-Benard problem for Pr=0.71 and Ra=5000. Please see section 3.2 of Kumar and Potherat JFM 2020 for the details of validation (attached in this email). Please download this version nektar++ from the following link https://gitlab.nektar.info/nektar/nektar/-/tree/b9f265928a72241b886a86eaedf4... This version corresponds to "Commit b9f26592". Let me know if you have any further queries. With regards Abhishek --------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom --------------------------------------------------------------------------------------- On Tue, Aug 18, 2020 at 8:12 PM Edward Threlfall <ejthrelfall@gmail.com> wrote:
This email from ejthrelfall@gmail.com 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 users,
I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++.
I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?).
I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too.
Many thanks,
Dr. Ed Threlfall (UKAEA). _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
--
Dear Professor Kumar, Many thanks for your help. Having obtained Nektar++ 4.5, I can run your example and I get output resembling your graphic. Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?). Anyhow, thanks for the excellent support. Regards, Ed. On Wed, Aug 19, 2020 at 12:39 AM Abhishek Kumar <abhishek.kir@gmail.com> wrote:
Dear Edward,
For Rayleigh-Benard convection, a BodyForce function is applied for the buoyancy term. Presently, it works perfectly with Nektar 4.5, but there is some issue in Nektar 5 for this function.
I have attached a xml file, which solves the Rayleigh-Benard problem for Pr=0.71 and Ra=5000. Please see section 3.2 of Kumar and Potherat JFM 2020 for the details of validation (attached in this email).
Please download this version nektar++ from the following link
https://gitlab.nektar.info/nektar/nektar/-/tree/b9f265928a72241b886a86eaedf4...
This version corresponds to "Commit b9f26592".
Let me know if you have any further queries.
With regards Abhishek
---------------------------------------------------------------------------------------
Abhishek Kumar
Assistant Professor (Research)
Centre for Fluid and Complex Systems
Coventry University, Coventry CV15FB
The United Kingdom
--------------------------------------------------------------------------------------- On Tue, Aug 18, 2020 at 8:12 PM Edward Threlfall <ejthrelfall@gmail.com> wrote:
This email from ejthrelfall@gmail.com 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 users,
I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++.
I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?).
I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too.
Many thanks,
Dr. Ed Threlfall (UKAEA). _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
--
Dear Edward, Abhishek, I had not realised we had broken that nek5.0 was not working as compared to 4.5. I had a quick look and found two loops where the range was not right. I have made a new branch fix/BouyancyForcing can you check to see if this works for you now and if so we can put in test and make a merge request. Cheers, Spencer. Spencer Sherwin FREng, FRAeS Head of Aerodynamics Section, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, South Kensington Campus, Imperial College London, SW7 2AZ, UK Phone: +44 (0)20 7594 5052 http://www.imperial.ac.uk/people/s.sherwin/ On 19 Aug 2020, at 18:08, Edward Threlfall <ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com>> wrote: Dear Professor Kumar, Many thanks for your help. Having obtained Nektar++ 4.5, I can run your example and I get output resembling your graphic. Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?). Anyhow, thanks for the excellent support. Regards, Ed. On Wed, Aug 19, 2020 at 12:39 AM Abhishek Kumar <abhishek.kir@gmail.com<mailto:abhishek.kir@gmail.com>> wrote: Dear Edward, For Rayleigh-Benard convection, a BodyForce function is applied for the buoyancy term. Presently, it works perfectly with Nektar 4.5, but there is some issue in Nektar 5 for this function. I have attached a xml file, which solves the Rayleigh-Benard problem for Pr=0.71 and Ra=5000. Please see section 3.2 of Kumar and Potherat JFM 2020 for the details of validation (attached in this email). Please download this version nektar++ from the following link https://gitlab.nektar.info/nektar/nektar/-/tree/b9f265928a72241b886a86eaedf4... This version corresponds to "Commit b9f26592". Let me know if you have any further queries. With regards Abhishek --------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom --------------------------------------------------------------------------------------- On Tue, Aug 18, 2020 at 8:12 PM Edward Threlfall <ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com>> wrote: This email from ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com> 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 users, I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++. I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?). I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too. Many thanks, Dr. Ed Threlfall (UKAEA). _______________________________________________ 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
Dear Professors, I've made the changes to my copy of Nektar++ 5.0 and rebuilt it. I have re-run Abhishek's example on this modified v.5.0: it no longer crashes and it produces output that looks the same as that from v.4.5. One thing I note is that if I now run it with MPI (I could not test this with v.4.5 as I did a serial build only; Windows user), I get different output in which there seems to be no convection - as if the equations are not coupled - is this to be expected? Many thanks for the help, Ed. On Thu, Aug 20, 2020 at 4:56 PM Sherwin, Spencer J <s.sherwin@imperial.ac.uk> wrote:
Dear Edward, Abhishek,
I had not realised we had broken that nek5.0 was not working as compared to 4.5. I had a quick look and found two loops where the range was not right. I have made a new branch
fix/BouyancyForcing
can you check to see if this works for you now and if so we can put in test and make a merge request.
Cheers, Spencer.
Spencer Sherwin FREng, FRAeS Head of Aerodynamics Section, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, South Kensington Campus, Imperial College London, SW7 2AZ, UK Phone: +44 (0)20 7594 5052 http://www.imperial.ac.uk/people/s.sherwin/
On 19 Aug 2020, at 18:08, Edward Threlfall <ejthrelfall@gmail.com> wrote:
Dear Professor Kumar,
Many thanks for your help. Having obtained Nektar++ 4.5, I can run your example and I get output resembling your graphic.
Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?).
Anyhow, thanks for the excellent support.
Regards,
Ed.
On Wed, Aug 19, 2020 at 12:39 AM Abhishek Kumar <abhishek.kir@gmail.com> wrote:
Dear Edward,
For Rayleigh-Benard convection, a BodyForce function is applied for the buoyancy term. Presently, it works perfectly with Nektar 4.5, but there is some issue in Nektar 5 for this function.
I have attached a xml file, which solves the Rayleigh-Benard problem for Pr=0.71 and Ra=5000. Please see section 3.2 of Kumar and Potherat JFM 2020 for the details of validation (attached in this email).
Please download this version nektar++ from the following link
https://gitlab.nektar.info/nektar/nektar/-/tree/b9f265928a72241b886a86eaedf4...
This version corresponds to "Commit b9f26592".
Let me know if you have any further queries.
With regards Abhishek
--------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom
--------------------------------------------------------------------------------------- On Tue, Aug 18, 2020 at 8:12 PM Edward Threlfall <ejthrelfall@gmail.com> wrote:
This email from ejthrelfall@gmail.com 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 users,
I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++.
I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?).
I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too.
Many thanks,
Dr. Ed Threlfall (UKAEA). _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
--
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
Dear Spencer, Thanks for fixing Nek5.0. I have checked with the new code and it is working perfectly. Dear Edward, One thing I note is that if I now run it with MPI (I could not test this with v.4.5 as I did a serial build only; Windows user), I get different output in which there seems to be no convection - as if the equations are not coupled - is this to be expected? There was an issue with the xml file, which I sent last time. I should have put some noise in the initial condition. I have attached the updated xml file, which will give you convective rolls while running in serial or parallel. Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?). When we add field "T" it acts as a passive scalar (see section 11.8 of the manual), and has the advective and the diffusive terms. Next, this passive scalar "T" is made active by using the BodyForce function. With regards Abhishek On Thu, Aug 20, 2020 at 6:35 PM Edward Threlfall <ejthrelfall@gmail.com> wrote:
Dear Professors,
I've made the changes to my copy of Nektar++ 5.0 and rebuilt it.
I have re-run Abhishek's example on this modified v.5.0: it no longer crashes and it produces output that looks the same as that from v.4.5.
One thing I note is that if I now run it with MPI (I could not test this with v.4.5 as I did a serial build only; Windows user), I get different output in which there seems to be no convection - as if the equations are not coupled - is this to be expected?
Many thanks for the help,
Ed.
On Thu, Aug 20, 2020 at 4:56 PM Sherwin, Spencer J < s.sherwin@imperial.ac.uk> wrote:
Dear Edward, Abhishek,
I had not realised we had broken that nek5.0 was not working as compared to 4.5. I had a quick look and found two loops where the range was not right. I have made a new branch
fix/BouyancyForcing
can you check to see if this works for you now and if so we can put in test and make a merge request.
Cheers, Spencer.
Spencer Sherwin FREng, FRAeS Head of Aerodynamics Section, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, South Kensington Campus, Imperial College London, SW7 2AZ, UK Phone: +44 (0)20 7594 5052 http://www.imperial.ac.uk/people/s.sherwin/
On 19 Aug 2020, at 18:08, Edward Threlfall <ejthrelfall@gmail.com> wrote:
Dear Professor Kumar,
Many thanks for your help. Having obtained Nektar++ 4.5, I can run your example and I get output resembling your graphic.
Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?).
Anyhow, thanks for the excellent support.
Regards,
Ed.
On Wed, Aug 19, 2020 at 12:39 AM Abhishek Kumar <abhishek.kir@gmail.com> wrote:
Dear Edward,
For Rayleigh-Benard convection, a BodyForce function is applied for the buoyancy term. Presently, it works perfectly with Nektar 4.5, but there is some issue in Nektar 5 for this function.
I have attached a xml file, which solves the Rayleigh-Benard problem for Pr=0.71 and Ra=5000. Please see section 3.2 of Kumar and Potherat JFM 2020 for the details of validation (attached in this email).
Please download this version nektar++ from the following link
https://gitlab.nektar.info/nektar/nektar/-/tree/b9f265928a72241b886a86eaedf4...
This version corresponds to "Commit b9f26592".
Let me know if you have any further queries.
With regards Abhishek
--------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom
--------------------------------------------------------------------------------------- On Tue, Aug 18, 2020 at 8:12 PM Edward Threlfall <ejthrelfall@gmail.com> wrote:
This email from ejthrelfall@gmail.com 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 users,
I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++.
I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?).
I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too.
Many thanks,
Dr. Ed Threlfall (UKAEA). _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
--
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
Dear Professor, Thanks again for the help - I confirm that I now see convection in the parallel version. Ed. On Thu, Aug 20, 2020 at 11:58 PM Abhishek Kumar <abhishek.kir@gmail.com> wrote:
Dear Spencer,
Thanks for fixing Nek5.0. I have checked with the new code and it is working perfectly.
Dear Edward,
One thing I note is that if I now run it with MPI (I could not test this with v.4.5 as I did a serial build only; Windows user), I get different output in which there seems to be no convection - as if the equations are not coupled - is this to be expected?
There was an issue with the xml file, which I sent last time. I should have put some noise in the initial condition. I have attached the updated xml file, which will give you convective rolls while running in serial or parallel.
Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?).
When we add field "T" it acts as a passive scalar (see section 11.8 of the manual), and has the advective and the diffusive terms. Next, this passive scalar "T" is made active by using the BodyForce function.
With regards Abhishek
On Thu, Aug 20, 2020 at 6:35 PM Edward Threlfall <ejthrelfall@gmail.com> wrote:
Dear Professors,
I've made the changes to my copy of Nektar++ 5.0 and rebuilt it.
I have re-run Abhishek's example on this modified v.5.0: it no longer crashes and it produces output that looks the same as that from v.4.5.
One thing I note is that if I now run it with MPI (I could not test this with v.4.5 as I did a serial build only; Windows user), I get different output in which there seems to be no convection - as if the equations are not coupled - is this to be expected?
Many thanks for the help,
Ed.
On Thu, Aug 20, 2020 at 4:56 PM Sherwin, Spencer J < s.sherwin@imperial.ac.uk> wrote:
Dear Edward, Abhishek,
I had not realised we had broken that nek5.0 was not working as compared to 4.5. I had a quick look and found two loops where the range was not right. I have made a new branch
fix/BouyancyForcing
can you check to see if this works for you now and if so we can put in test and make a merge request.
Cheers, Spencer.
Spencer Sherwin FREng, FRAeS Head of Aerodynamics Section, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, South Kensington Campus, Imperial College London, SW7 2AZ, UK Phone: +44 (0)20 7594 5052 http://www.imperial.ac.uk/people/s.sherwin/
On 19 Aug 2020, at 18:08, Edward Threlfall <ejthrelfall@gmail.com> wrote:
Dear Professor Kumar,
Many thanks for your help. Having obtained Nektar++ 4.5, I can run your example and I get output resembling your graphic.
Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?).
Anyhow, thanks for the excellent support.
Regards,
Ed.
On Wed, Aug 19, 2020 at 12:39 AM Abhishek Kumar <abhishek.kir@gmail.com> wrote:
Dear Edward,
For Rayleigh-Benard convection, a BodyForce function is applied for the buoyancy term. Presently, it works perfectly with Nektar 4.5, but there is some issue in Nektar 5 for this function.
I have attached a xml file, which solves the Rayleigh-Benard problem for Pr=0.71 and Ra=5000. Please see section 3.2 of Kumar and Potherat JFM 2020 for the details of validation (attached in this email).
Please download this version nektar++ from the following link
https://gitlab.nektar.info/nektar/nektar/-/tree/b9f265928a72241b886a86eaedf4...
This version corresponds to "Commit b9f26592".
Let me know if you have any further queries.
With regards Abhishek
--------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom
--------------------------------------------------------------------------------------- On Tue, Aug 18, 2020 at 8:12 PM Edward Threlfall <ejthrelfall@gmail.com> wrote:
This email from ejthrelfall@gmail.com 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 users,
I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++.
I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?).
I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too.
Many thanks,
Dr. Ed Threlfall (UKAEA). _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
--
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
OK that sounds good. Need to get this fix merged then. Cheers, Spencer. Spencer Sherwin FREng, FRAeS Head of Aerodynamics Section, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, South Kensington Campus, Imperial College London, SW7 2AZ, UK Phone: +44 (0)20 7594 5052 http://www.imperial.ac.uk/people/s.sherwin/ On 21 Aug 2020, at 10:19, Edward Threlfall <ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com>> wrote: Dear Professor, Thanks again for the help - I confirm that I now see convection in the parallel version. Ed. On Thu, Aug 20, 2020 at 11:58 PM Abhishek Kumar <abhishek.kir@gmail.com<mailto:abhishek.kir@gmail.com>> wrote: Dear Spencer, Thanks for fixing Nek5.0. I have checked with the new code and it is working perfectly. Dear Edward, One thing I note is that if I now run it with MPI (I could not test this with v.4.5 as I did a serial build only; Windows user), I get different output in which there seems to be no convection - as if the equations are not coupled - is this to be expected? There was an issue with the xml file, which I sent last time. I should have put some noise in the initial condition. I have attached the updated xml file, which will give you convective rolls while running in serial or parallel. Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?). When we add field "T" it acts as a passive scalar (see section 11.8 of the manual), and has the advective and the diffusive terms. Next, this passive scalar "T" is made active by using the BodyForce function. With regards Abhishek On Thu, Aug 20, 2020 at 6:35 PM Edward Threlfall <ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com>> wrote: Dear Professors, I've made the changes to my copy of Nektar++ 5.0 and rebuilt it. I have re-run Abhishek's example on this modified v.5.0: it no longer crashes and it produces output that looks the same as that from v.4.5. One thing I note is that if I now run it with MPI (I could not test this with v.4.5 as I did a serial build only; Windows user), I get different output in which there seems to be no convection - as if the equations are not coupled - is this to be expected? Many thanks for the help, Ed. On Thu, Aug 20, 2020 at 4:56 PM Sherwin, Spencer J <s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk>> wrote: Dear Edward, Abhishek, I had not realised we had broken that nek5.0 was not working as compared to 4.5. I had a quick look and found two loops where the range was not right. I have made a new branch fix/BouyancyForcing can you check to see if this works for you now and if so we can put in test and make a merge request. Cheers, Spencer. Spencer Sherwin FREng, FRAeS Head of Aerodynamics Section, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, South Kensington Campus, Imperial College London, SW7 2AZ, UK Phone: +44 (0)20 7594 5052 http://www.imperial.ac.uk/people/s.sherwin/ On 19 Aug 2020, at 18:08, Edward Threlfall <ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com>> wrote: Dear Professor Kumar, Many thanks for your help. Having obtained Nektar++ 4.5, I can run your example and I get output resembling your graphic. Looking at the xml file, it is a bit of a mystery to me how Nektar++ knows that it has to treat the temperature as a linear advection-diffusion problem (is this a default behaviour?). Anyhow, thanks for the excellent support. Regards, Ed. On Wed, Aug 19, 2020 at 12:39 AM Abhishek Kumar <abhishek.kir@gmail.com<mailto:abhishek.kir@gmail.com>> wrote: Dear Edward, For Rayleigh-Benard convection, a BodyForce function is applied for the buoyancy term. Presently, it works perfectly with Nektar 4.5, but there is some issue in Nektar 5 for this function. I have attached a xml file, which solves the Rayleigh-Benard problem for Pr=0.71 and Ra=5000. Please see section 3.2 of Kumar and Potherat JFM 2020 for the details of validation (attached in this email). Please download this version nektar++ from the following link https://gitlab.nektar.info/nektar/nektar/-/tree/b9f265928a72241b886a86eaedf4... This version corresponds to "Commit b9f26592". Let me know if you have any further queries. With regards Abhishek --------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom --------------------------------------------------------------------------------------- On Tue, Aug 18, 2020 at 8:12 PM Edward Threlfall <ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com>> wrote: This email from ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com> 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 users, I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++. I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?). I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too. Many thanks, Dr. Ed Threlfall (UKAEA). _______________________________________________ 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
participants (3)
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Abhishek Kumar
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Edward Threlfall
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Sherwin, Spencer J