FLUENT: how to record drag force at every time step?

qiulan · January 4, 2013, 23:55

Hi all,

I want to record the drag forces at each time step. At first, I use solve/monitors/force to save the drag force data, but the data upstate at each time step and only the newest ones remain. So I use the command "unsteady-monitors-itera? yes". However, only data in the iterations during the newest one time step were recorded. That is, drag force still updated in each time step. Can anybody tell me how I can save the drag forces at each time step? If udf is required, how to write the drag force? I mean use what macro to represent the drag force?

Thank you very much!

Best wishes,

Qiulan

rasoulb · January 5, 2013, 15:11

Hi,

you can select "/solve/monitors/force" then select write in options to write force in a file. then you have forces in all time step.

qiulan · January 5, 2013, 20:27

Hi Rasoulb,

Thanks. However, I want to record three force, including the drag force, lift force, and side force at the same time. However, in ansys 13.0, only drag force and lift force are available under "/solve/monitors/force". How can I solve this problem?

Any suggestions are appreciated.

Thank you very much!

Best wishes,

Qiulan

Ema40 · December 19, 2014, 03:43

Hi.

I have a similar problem for a turbine with the moment coefficient.
I have done your advises but the output Cm overwrites at every time step.

Can you help me? There is a specified output file name in order to obtain the time history?

Thank you

CFD2016 · March 20, 2017, 21:22

Hi,

In Fluent, we can write the Cd at each time step.
Is there anyone know how to write the Cd components (Cf and Cp) and each time step?

Thank you very much.

January 4, 2013, 23:55	FLUENT: how to record drag force at every time step?	#1
qiulan New Member Qiulan Zeng Join Date: Sep 2010 Posts: 18 Rep Power: 15	Hi all, I want to record the drag forces at each time step. At first, I use solve/monitors/force to save the drag force data, but the data upstate at each time step and only the newest ones remain. So I use the command "unsteady-monitors-itera? yes". However, only data in the iterations during the newest one time step were recorded. That is, drag force still updated in each time step. Can anybody tell me how I can save the drag forces at each time step? If udf is required, how to write the drag force? I mean use what macro to represent the drag force? Thank you very much! Best wishes, Qiulan

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January 5, 2013, 15:11		#2
rasoulb New Member rasoul b Join Date: Dec 2010 Location: iran Posts: 13 Rep Power: 15	Hi, you can select "/solve/monitors/force" then select write in options to write force in a file. then you have forces in all time step.

January 5, 2013, 20:27		#3
qiulan New Member Qiulan Zeng Join Date: Sep 2010 Posts: 18 Rep Power: 15	Hi Rasoulb, Thanks. However, I want to record three force, including the drag force, lift force, and side force at the same time. However, in ansys 13.0, only drag force and lift force are available under "/solve/monitors/force". How can I solve this problem? Any suggestions are appreciated. Thank you very much! Best wishes, Qiulan

December 19, 2014, 03:43		#4
Ema40 Senior Member Join Date: Oct 2014 Posts: 124 Rep Power: 11	Hi. I have a similar problem for a turbine with the moment coefficient. I have done your advises but the output Cm overwrites at every time step. Can you help me? There is a specified output file name in order to obtain the time history? Thank you

March 20, 2017, 21:22		#5
CFD2016 New Member Join Date: May 2016 Posts: 12 Rep Power: 9	Hi, In Fluent, we can write the Cd at each time step. Is there anyone know how to write the Cd components (Cf and Cp) and each time step? Thank you very much.