CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Programming & Development

TKE production and Dissipation for DNS

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

LinkBack Thread Tools Search this Thread Display Modes
Old   March 30, 2020, 21:50
Default TKE production and Dissipation for DNS
Akshay Patil
Join Date: Nov 2015
Location: Pune, India
Posts: 34
Rep Power: 7
Akshay_11235 is on a distinguished road
Hi guys,

I am working on a DNS calculation and would like to confirm if the TKE production and Dissipation calculations on the fly make sense. I am constantly getting about one order of magnitude difference between production term and dissipation term.

in my code Production is defined as (Production = -ui'uj'dui/dxj)

volSymmTensorField gradU = symm(fvc::grad(U));
volScalarField prod = -((U - u_bar)*(U - u_bar)) && gradU;
//Take the volume average in the domain
dimensionedScalar production = average(prod);
and Dissipation is defined as (Dissipation = nu du'i/dxj du'i/dxj)

volTensorField gradUprime = fvc::grad(U-u_bar);
volScalarField eps = nu*(gradUprime && gradUprime);
//Take the volume average in the domain
dimensionedScalar dissipation = average(eps);

When I do this the TKE production < dissipation by about an order of magnitude. I have checked the dependence of the mesh on this and it is consistently the same so I am wondering if I did something wrong here.

I am using C-N for the viscous temporal discretisation while all other settings are second order. I have also switched off the extra phi term in the Piso algorithm which stabilises the solver. Would be grateful to hear what you think. Thanks!


Akshay Patil
Akshay_11235 is offline   Reply With Quote


dissipation, dns, production, tke

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
Howto get the production and dissipation of TKE?? lakeat OpenFOAM Running, Solving & CFD 8 July 9, 2016 04:56
TKE budget estimation by k-epsilon model pd.iiest FLUENT 1 March 12, 2016 11:25
Production TKE in LES CeesH FLUENT 2 March 8, 2016 02:38
Budgets of Reynolds shear stress (TKE budgets) FLUENT 0 March 16, 2015 07:10
Turbulent Dissipation Rates - epsilon Otute Main CFD Forum 5 May 20, 1999 10:51

All times are GMT -4. The time now is 00:50.