Data export - temporal average of HTC and Temp with locations (x,y,z)

kri321shna · December 12, 2016, 18:35

Hi,

I have raise a thread in Ensight about exporting htc, temp (temporal averaged), & location (x,y,z). Solved in Converge.

I can use post_convert but, when i use column format-- i am getting above data for every time.

if I use 12 option[Average of selected post output files] in post convert, it is given below error eventhough if i select more

"error: must select more than one post files"

For some more info, refer this link in Ensight forum.

Data export - temporal average of HTC and Temp with locations (x,y,z)

SamWijey · December 12, 2016, 19:18

Option 12 in post_convert is to average several post files. Imagine you run multiple realizations of an LES spray simulation and you'd like to see an average of all these different realizations. That's when you use this option.

CONVERGE writes out another output file called transfer.out where temporally averaged HTC, near wall temperature, etc.. are given per every boundary cell.

Please refer to CONVERGE theory manual for more details.

kri321shna · December 13, 2016, 15:52

Thank you SamWijey

there is no file as transfer.out in simulation folder presently.

I think, post_convert option 12 for data averaging for given crank angles or time steps. is it right ?

if not, how can i get for liner(moving mesh) averaged htc and temperature ?

Thank you so much.

Krishna

MFGT · December 14, 2016, 05:10

You have to set "wall_output_flag=1" for wall output for each boundary (average HTC, bound Temp etc..) and transfer_flag=1 for the FEA htc data.
Both settings are in inputs.in

kri321shna · December 14, 2016, 13:43

Thank you MFGT.

changing wall flag to 1 is very much useful to my requirement.

Here I am using G equation model for combustion and temperature was ~784 K at 6BTDC (before ignition). It is increased up to ~834 K by 1BTDC. and sudden fall to 796 K at TDC. I used 0.015 J of heat addition from plug for 4 CA.

Heat addition and ignition duration is my own assumptions.

anything to be change?

Is G eqn is appropriate for combustion model or can I choose SAGE?

Thanks.

MFGT · December 15, 2016, 07:56

These are questions one can difficult answer without knowing the case.

But first, to ignite the mixture with G-Eq., you dont need to add Energy, you have to add the G_EQ passive instead. Have a look at the example case.

Regarding the durations, i use 0.5 and 10CA for SAGE, representing arc and glow phase(like the example cases there), both with 0.03J. I am not sure here how to adjust these if the RPM is changed a lot (from 1500 to 5500 rpm for example).

Depending on operating point, you should use SAGE to get more predictive results. Make sure you have an appropriate mechanism for the fuel you are using.

December 12, 2016, 18:35	Data export - temporal average of HTC and Temp with locations (x,y,z)	#1
kri321shna Member Krishna Join Date: Apr 2012 Posts: 54 Rep Power: 14	Hi, I have raise a thread in Ensight about exporting htc, temp (temporal averaged), & location (x,y,z). Solved in Converge. I can use post_convert but, when i use column format-- i am getting above data for every time. if I use 12 option[Average of selected post output files] in post convert, it is given below error eventhough if i select more "error: must select more than one post files" For some more info, refer this link in Ensight forum. Data export - temporal average of HTC and Temp with locations (x,y,z)

December 12, 2016, 19:18		#2
SamWijey Senior Member Sameera Wijeyakulasuriya Join Date: Jan 2016 Location: Convergent Science, Madison WI Posts: 117 Rep Power: 10	Option 12 in post_convert is to average several post files. Imagine you run multiple realizations of an LES spray simulation and you'd like to see an average of all these different realizations. That's when you use this option. CONVERGE writes out another output file called transfer.out where temporally averaged HTC, near wall temperature, etc.. are given per every boundary cell. Please refer to CONVERGE theory manual for more details. __________________ Sameera Wijeyakulasuriya Principal Engineer, Applications CONVERGECFD

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Data export - temporal average of HTC and Temp with locations (x,y,z)	kri321shna	EnSight	1	December 12, 2016 22:38

December 13, 2016, 15:52		#3
kri321shna Member Krishna Join Date: Apr 2012 Posts: 54 Rep Power: 14	Thank you SamWijey there is no file as transfer.out in simulation folder presently. I think, post_convert option 12 for data averaging for given crank angles or time steps. is it right ? if not, how can i get for liner(moving mesh) averaged htc and temperature ? Thank you so much. Krishna

December 14, 2016, 05:10		#4
MFGT Senior Member Tobias Join Date: May 2016 Location: Germany Posts: 295 Rep Power: 11	You have to set "wall_output_flag=1" for wall output for each boundary (average HTC, bound Temp etc..) and transfer_flag=1 for the FEA htc data. Both settings are in inputs.in

December 14, 2016, 13:43		#5
kri321shna Member Krishna Join Date: Apr 2012 Posts: 54 Rep Power: 14	Thank you MFGT. changing wall flag to 1 is very much useful to my requirement. Here I am using G equation model for combustion and temperature was ~784 K at 6BTDC (before ignition). It is increased up to ~834 K by 1BTDC. and sudden fall to 796 K at TDC. I used 0.015 J of heat addition from plug for 4 CA. Heat addition and ignition duration is my own assumptions. anything to be change? Is G eqn is appropriate for combustion model or can I choose SAGE? Thanks.

December 15, 2016, 07:56		#6
MFGT Senior Member Tobias Join Date: May 2016 Location: Germany Posts: 295 Rep Power: 11	These are questions one can difficult answer without knowing the case. But first, to ignite the mixture with G-Eq., you dont need to add Energy, you have to add the G_EQ passive instead. Have a look at the example case. Regarding the durations, i use 0.5 and 10CA for SAGE, representing arc and glow phase(like the example cases there), both with 0.03J. I am not sure here how to adjust these if the RPM is changed a lot (from 1500 to 5500 rpm for example). Depending on operating point, you should use SAGE to get more predictive results. Make sure you have an appropriate mechanism for the fuel you are using.