CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Drag coefficient implementation

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   November 24, 2020, 11:02
Default Drag coefficient implementation
New Member
Sumit Peh
Join Date: Oct 2018
Location: Beijing
Posts: 20
Rep Power: 5
Jamessmp23 is on a distinguished road
Hi Foamers

I would like to apply equations of other Drag coefficient in 4 conditions of Renold's number.
[Re<1 // 1<Re<100 // 100<Re<1000 // Re>1000]

SchillerNaumann has 2 conditions of Re which are Re<1000 and Re>1000
Here is the SchillerNaumann code on ~dragModels
I supposed neg(Re - 1000) is this Re<1000 condition and pos0(Re - 1000) is the Re>1000.

    volScalarField Re(max(Ur*phase1_.d()/, scalar(1.0e-3)));
    volScalarField Cds
        neg(Re - 1000)*(24.0*(1.0 + 0.15*pow(Re, 0.687))/Re)
      + pos0(Re - 1000)*0.44

    return 0.75*Cds*phase2_.rho()*Ur/phase1_.d();
Is there a way to write code for more than 2 conditions ?

As my imagination, I guess maybe my case would be
    volScalarField Re(max(Ur*phase1_.d()/, scalar(1.0e-3)));
    volScalarField Cds
        neg(Re - 1)*(Equation1)
      + neg1(Re - 100)*(Equation2)
      + neg100(Re - 1000)*(Equation3)
      + pos0(Re - 1000)*(Equation4)

    return 0.75*Cds*phase2_.rho()*Ur/phase1_.d();
Please confirm if i'm right and please correct if i'm wrong.

Thanks in advanced

Jamessmp23 is offline   Reply With Quote


cfd, drag, drag coefficient, openfoam

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Drag Force Ratio for Flat Plate Rob Wilk Main CFD Forum 40 May 10, 2020 04:47
Default Need help with Drag Coefficient using ANSYS Fluent welskein ANSYS 0 March 30, 2020 03:56
problem with saving drag coefficient colopolo FLUENT 5 April 12, 2013 10:59
Calculation of Drag Coefficient, Help Please teek22 CFX 1 April 26, 2012 18:41

All times are GMT -4. The time now is 05:01.