In dire need of a fast reply; Steady state or transient?

hashem_1064 · October 12, 2009, 04:18

hi all
for a two phase modeling of a boat using CFX in order to calculate value of lift and drag, which kind of simulation should be performed? transient or steady state?

thank you all

ghorrocks · October 12, 2009, 07:17

Two phase models or things like boats are generally best run transient. Convergence is difficult in steady state. Transient simulations are very slow, so you will have to be patient.

hashem_1064 · October 12, 2009, 14:36

thank Glenn
why should it be treated as a transient phenomena? i just need lift and drag for a given speed! this case is likely a steady state one.

ghorrocks · October 12, 2009, 19:05

As I said previously - convergence is difficult in steady state.

October 12, 2009, 04:18	In dire need of a fast reply; Steady state or transient?	#1
hashem_1064 New Member hashem Join Date: May 2009 Posts: 17 Rep Power: 17	hi all for a two phase modeling of a boat using CFX in order to calculate value of lift and drag, which kind of simulation should be performed? transient or steady state? thank you all

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October 12, 2009, 07:17		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Two phase models or things like boats are generally best run transient. Convergence is difficult in steady state. Transient simulations are very slow, so you will have to be patient.

October 12, 2009, 14:36		#3
hashem_1064 New Member hashem Join Date: May 2009 Posts: 17 Rep Power: 17	thank Glenn why should it be treated as a transient phenomena? i just need lift and drag for a given speed! this case is likely a steady state one.

October 12, 2009, 19:05		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	As I said previously - convergence is difficult in steady state.