Energy Balance Equation not balanced

ralph nutella · April 1, 2012, 04:23

Hello good people,
I recently did a cfd simulation on Fluent using the k-epsilon model. I did not add any source term. just a normal run over a bump.(flow over bluff body).
When all the residuals converged (1e-05), i checked the advection terms, the dissipation terms, the diffusion terms and the production terms. but they do not balance according to the turbulent kinetic energy equation. Can anybody please tell me why this is so and what could possibly be the problem?

Many thanks

ralph nutella · April 16, 2012, 05:26

so can anybody tell me why it says i have 1e-05 for my residuals for continuity but when i checked du/dx+ dv/dy, it does not sum to 0? infact, the difference is huge. Please help. Glenn Horrocks or any other senior members out there...

LuckyTran · April 16, 2012, 22:36

Quote:

Originally Posted by ralph nutella

so can anybody tell me why it says i have 1e-05 for my residuals for continuity but when i checked du/dx+ dv/dy, it does not sum to 0? infact, the difference is huge. Please help. Glenn Horrocks or any other senior members out there...

The reported residual is a scaled residual. See the fluent help documentation for details. The residual for continuity as reported by fluent is NOT how much imbalance there is.

April 1, 2012, 04:23	Energy Balance Equation not balanced	#1
ralph nutella New Member Join Date: Apr 2012 Posts: 2 Rep Power: 0	Hello good people, I recently did a cfd simulation on Fluent using the k-epsilon model. I did not add any source term. just a normal run over a bump.(flow over bluff body). When all the residuals converged (1e-05), i checked the advection terms, the dissipation terms, the diffusion terms and the production terms. but they do not balance according to the turbulent kinetic energy equation. Can anybody please tell me why this is so and what could possibly be the problem? Many thanks

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Calculation of the Governing Equations	Mihail	CFX	7	September 7, 2014 07:27
volumetric reaction and energy balance?	m.beh	FLUENT	1	October 17, 2011 18:21
ATTENTION! Reliability problems in CFX 5.7	Joseph	CFX	14	April 20, 2010 16:45
Viscosity and the Energy Equation	Rich	Main CFD Forum	0	December 16, 2009 15:01
question about energy equation	zhou	FLUENT	0	February 24, 2004 00:55

April 16, 2012, 05:26		#2
ralph nutella New Member Join Date: Apr 2012 Posts: 2 Rep Power: 0	so can anybody tell me why it says i have 1e-05 for my residuals for continuity but when i checked du/dx+ dv/dy, it does not sum to 0? infact, the difference is huge. Please help. Glenn Horrocks or any other senior members out there...