Shear Flow

Nazrin
Nazrin Altair Community Member
edited October 2020 in Community Q&A

Hello every one.

 

I need help. How to generate shear flow at velocity inlet & nodal initial condition at AcuSolve (as attach picture).  For now, i only want to simulate shear flow in empty domain. After shear flow successfully generate, i want to put riser in the domain.

<?xml version="1.0" encoding="UTF-8"?>Shear flow.PNG

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Answers

  • acupro
    acupro
    Altair Employee
    edited February 2020

    Let's assume the flow direction is X (right to left in your picture) and the vertical direction is Z (bottom to top in your picture).  In Nodal Boundary Condition, variable is x-velocity, type is piecewise-linear.  Curve-fit-variable is z-coordinate - then enter the values (table) for x-velocity as a function of z-coordinate.  Should be similar for Nodal Initial Condition.  This will give the same profile everywhere - no difference for the side and top walls.

  • Nazrin
    Nazrin Altair Community Member
    edited February 2020
    Altair Forum User said:

    Let's assume the flow direction is X (right to left in your picture) and the vertical direction is Z (bottom to top in your picture).  In Nodal Boundary Condition, variable is x-velocity, type is piecewise-linear.  Curve-fit-variable is z-coordinate - then enter the values (table) for x-velocity as a function of z-coordinate.  Should be similar for Nodal Initial Condition.  This will give the same profile everywhere - no difference for the side and top walls.

    Dear Acupro,

    i have tried the solution you provided but still, unsuccessful.

    at nodal initial condition, i need to use script instead of built in table at nodal boundary condition.

    Is it possible for u to fix my mistake using my .acs file as attach?

    my domain as follow:

                   X Min/Max: -20.0  20.0
                   Y Min/Max: -10.0  -10.0
                   Z Min/Max: -20.0  0.0

    flow direction: positive x

     

    Unable to find an attachment - read this blog

  • acupro
    acupro
    Altair Employee
    edited February 2020

    1.  For the inlet NBC, you may want to use cubic-spline rather than linear.  It depends on if you want linear or cubic interpolation between your given data points.

    2.  For the NIC, you have two choices, since piecewise linear is not available in AcuConsole.  You can either use a tool like Excel to determine the equation for the velocity based on Z - and use 'Script' in AcuConsole.  Or you'll need to edit the input file once written, and use piecewise-linear (or cubic spline), as described in the Command Reference Manual under Nodal Data Commands > Nodal Initial Condition, which will then be similar to the NBC.

  • Nazrin
    Nazrin Altair Community Member
    edited February 2020

    Dear AcuPro,

     

    Its working!!!

     

    TQVM!

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