Hi Dustin, In the case of 3DH1D with constant flowrate (in the z direction), kinvis should be scaled according to the user's definition of the Reynolds number. For instance, if the definition of the Reynolds number is Re = 2 * Ubulk * h / nu, then nu = 2 * Ubulk * h / Re. The flow-rate parameter actually refers to the volumetric flux - flow rate (m^3 s^-1) normalised by the surface area (m^2), so you wouldn't need to take into account LZ in this case. Hope this helps! Regards, Chi Hin ________________________________ From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of Ma, Ting-Hsuan <TIM48@pitt.edu> Sent: 09 May 2023 04:53 To: nektar-users <nektar-users@imperial.ac.uk> Subject: [Nektar-users] Flowrate Enforcement Question This email from TIM48@pitt.edu 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, This may be a dumb question, but when we are setting a flowrate for a 3D1H problem (flow in the x-y and homogenous expansion in the Z). How would I set my Kinvis such that it follows the Reynolds number I am targeting? Within the parameters, enables the tag "Flowrate = 1.0". If I am doing a homogenous expansion in the z-direction, would I need to take into account LZ? or is this done automatically through the code? I am getting confused by the notations that is used within the user manual, and looking within the source code does not help me too much as both versions do not explicitly state to take into account the area of just the line. Any insight is appreciated, Dustin