November 2023 - Nektar-users

Homogenous Spanwise Averaging
by Ma, Ting-Hsuan 27 Nov '23

27 Nov '23

******************* 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. ******************* Hi all, I am currently working on obtaining DNS data and have successfully provided Nektar with a 2D mesh (XY) for streamwise and wall-normal directions. Utilizing Nektar's homogeneous expansion in the spanwise direction, I've managed to acquire my 3D turbulence data. However, I'm looking for a function that can return a 2D XY plane of all averaged components by averaging in the spanwise, homogeneous direction. While the Filter "ReynoldsStresses" can provide the 3D time-averaged fields, I was wondering if there's a function specifically designed performing the averaging/output that I have specified. I've checked the user guide without finding relevant information. Any guidance or pointers would be greatly appreciated. Thanks, Dustin

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Buoyancy-Driven Compressible Flow Problem
by 谢亚广 19 Nov '23

19 Nov '23

******************* 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 ALL,I would like to use the Nektar++ compressible solver for simulating buoyancy-driven flow. So I need to set different temperatures for each wall, but I've noticed that the Twall is defined uniformly for all walls and cannot be set individually for each wall. Is there a way to meet my requirements? I would greatly appreciate any assistance!Kind regardsYaguang Xie

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Jupyter Notebook Tutorials
by Alexander Schukmann 19 Nov '23

19 Nov '23

******************* 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. ******************* Hi, it seems like it's not possible anymore to run the interactive jupyter notebook tutorials using the cloud resources, as stated on the homepage. Will this issue be resolved in the future? All the best Alex Sicher versendet mit [Proton Mail](https://proton.me/).

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GitLab Account
by Rahul Venkatesh 17 Nov '23

17 Nov '23

******************* 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. ******************* Hello, I have been using Nektar++ for my research. Could you please subscribe me to the GitLab Account. Please find attached the error message i am facing while trying to register as a new user. Thanks and regards *Rahul Venkatesan* PhD Student (Fall 2022) School of Mechatronics Engineering (Mechanics) BIT application number - 20220100159 Student ID - 3820222033 Phone number - 00918220320433

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Implicit diffusion with variable D
by Futtersack, Romain 06 Nov '23

06 Nov '23

******************* 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. ******************* Hello Nektar++ community ! Trying to learn how think work, it is not obvious how to solve some laplacians. I did a first go based on https://github.com/ExCALIBUR-NEPTUNE/nektar-diffusion<https://github.com/ExCALIBUR-NEPTUNE/nektar-diffusion/blob/d9d3584530cb60f3…>, which let you solve d_t X = - nabla . (D nabla X) + S using the StdRegions::VarCoeffMap varcoeffs; However trying to modify them during the run has no impact. I guess this is because laplacian is defined only at initialisation with the Implicit time integration method (--verbose tells me Helmholtz operator is "Matrix free"), but even using ImplicitFull doesn't seem to see modification in the factors. So I have two related issues : 1. My D is evolving in time, so what would be the correct setup for time integration and/or solver attributes ? 2. I in fact need to solve two (or more) equations with laplacians, different D for each (and one is without temporal dimension nabla^2 X = S), but how do you define two separate Helmhotz solve for different unknown ? Many thanks in advance for your helpful answers, Romain Futtersack

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