transient simulation

Noman Hafeez · October 23, 2017, 04:15

how we can decide that the simulation will be transient or steady state? i am modeling a turbine and i need to know that what is the main difference b/w steady and transient state modeling in terms of physics???/

ghorrocks · October 23, 2017, 05:35

Mathematically: For a steady state run the time derivative of all variables tends to zero. Transient runs have non-zero time derivatives.

Practically: A converged steady run is the same forever and never changes. Transient runs keep changing.

Simulations: A steady state run will converge if simulated by a steady state or a transient run (as the transient run will just converge to the steady solution). A transient run will only converge if simulated transient, and will not converge if simulated steady state.

October 23, 2017, 04:15	transient simulation	#1
Noman Hafeez New Member Noman Hafeez Join Date: Jul 2017 Posts: 6 Rep Power: 8	how we can decide that the simulation will be transient or steady state? i am modeling a turbine and i need to know that what is the main difference b/w steady and transient state modeling in terms of physics???/

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Continuing transient simulation after steady simulation	billy7590	FLUENT	0	September 19, 2017 08:56
Transient RANS Simulation	Bazinga	Main CFD Forum	5	June 21, 2017 11:21
Transient simulation diverges	Graduation	ANSYS	0	February 28, 2012 07:13
How to integrate variable in a transient simulation?	nprace	CFX	4	January 9, 2012 08:59
Beginning a Transient Simulation	Norflow	CFX	2	October 7, 2011 00:38

October 23, 2017, 05:35		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,705 Rep Power: 143	Mathematically: For a steady state run the time derivative of all variables tends to zero. Transient runs have non-zero time derivatives. Practically: A converged steady run is the same forever and never changes. Transient runs keep changing. Simulations: A steady state run will converge if simulated by a steady state or a transient run (as the transient run will just converge to the steady solution). A transient run will only converge if simulated transient, and will not converge if simulated steady state.