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Fire Dynamics Simulator
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Getting Different Results for the same Input File - FDS v.6.3.2 #3398

Closed DineshMyilsamy closed 4 years ago

DineshMyilsamy commented 8 years ago

Dear Sir, I am Dinesh Myilsamy, currently I am working on a project which is based on compartment fire in an under ventilated condition.

OUTLINE OF MY RESEARCH:

Hot unburnt fuel mixtures (at 373 K)  will be present inside a closed compartment and there is an ignition source which is kept at one of the compartment  (Temp. 1500 k at its top surface), when the compartment window is opened the atmospheric air will get into the compartment due to the density difference. Fresh air will start to move inside the compartment and it will reach to the ignition source which is kept at other end of the compartment (opposite to window).

When the fresh air reacts with the unburnt fuel in the presence of ignition source there will be a rapid flame propagation (BACKDRAFT) inside the compartment with and it moves out of the compartment as a fireball.

picture1

          This has to be carried out using LES Turbulence Model and EDC as a combustion Model.

MY ISSUES.

        1.  For my simulation I am using FDS v.6.3.2 in an  Intel Core 2 E8400, 3.0 GHz, 32 Core Cluster. - Linux Operating system.

         I am getting two different solutions when I tried to simulate my  FDS input file. 

         I did not even change a single letter in my FDS file, I used the same computer, using 15 Cores. but I found a two different solution.

press

       2.  To resolve this problem I got a guidance from FDS google group. In that they adviced me to use   NOISE =.FALSE.

          I have tried by specifying NOISE=.FALSE,  NOISE_VELOCITY = 0.005 but the problem didn't get resolved

noise_005

My input parameters

MISC PARAMETERS

& MISC TMPA=25.0, DNS=.FALSE., NOISE=.FALSE., NOISE_VELOCITY=0.005, SUPPRESSION=.FALSE. / & RADI RADIATION=.TRUE./

REAC PARAMETERS

& REAC FUEL='METHANE', SPEC_ID_NU='METHANE','OXYGEN','CARBON DIOXIDE','WATER VAPOR' NU=-1,-2,1,2, SPEC_ID_N_S='METHANE','OXYGEN', A = 5.2E13, N_S= 1,1, HEAT_OF_COMBUSTION = 50240, E = 123980.0 FIXED_MIX_TIME=0.003/

IGNITION SOURCE REACTION TIME

&RAMP ID='N2_V', T= 0.000, F= 0.0 / &RAMP ID='N2_V', T= 3.000, F= 0.0 / &RAMP ID='N2_V', T= 3.500, F= 1.0 / &RAMP ID='N2_V', T= 4.000, F= 0.0 / &RAMP ID='N2_V', T= 10.00, F= 0.0 / / &RAMP ID='N2_T', T= 0.000, F= 0.0 / &RAMP ID='N2_T', T= 3.000, F= 0.0 / &RAMP ID='N2_T', T= 3.500, F= 1.0 / &RAMP ID='N2_T', T= 4.000, F= 0.0 / &RAMP ID='N2_T', T= 10.00, F= 0.0 /

rmcdermo commented 8 years ago

Please post your input file. Change the extension to *.txt and attach it to your post. Thanks.

DineshMyilsamy commented 8 years ago

For your information Hereby I have attached my input file.

Temp_100_FMT_1_00.txt

mcgratta commented 8 years ago

I'll take a look at this case. It is possible that the difference in results is due to the order in which the different MPI processes progress through a time step. Just a hunch at this point.

DineshMyilsamy commented 8 years ago

Okay Sir, I did as like you said

On Tue, Jan 26, 2016 at 9:09 PM, Randy McDermott notifications@github.com wrote:

Please post your input file. Change the extension to *.txt and attach it to your post. Thanks.

— Reply to this email directly or view it on GitHub https://github.com/firemodels/fds-smv/issues/3398#issuecomment-174974453 .

mcgratta commented 8 years ago

Which pressure device did you plot?

mcgratta commented 8 years ago

I ran the case twice. The results for the first pressure device are identical.

DineshMyilsamy commented 8 years ago

I have plotted for the device ID='P_WALL_01

On Wed, Jan 27, 2016 at 8:00 AM, Kevin McGrattan notifications@github.com wrote:

I ran the case twice. The results for the first pressure device are identical.

— Reply to this email directly or view it on GitHub https://github.com/firemodels/fds-smv/issues/3398#issuecomment-175283009 .

DineshMyilsamy commented 8 years ago

Hi Sir,

Very nice to hear that from you

Did you make any changes in that input file ?

Have you seen at other Devc location is it same?

May I know how many cores did you used and your computer configuration

On Wed, Jan 27, 2016 at 8:00 AM, Kevin McGrattan notifications@github.com wrote:

I ran the case twice. The results for the first pressure device are identical.

— Reply to this email directly or view it on GitHub https://github.com/firemodels/fds-smv/issues/3398#issuecomment-175283009 .

DineshMyilsamy commented 8 years ago

Hello Sir, (Mr.Kevin McGrattan & Randy McDermott)

       I am sorry to bother you,

      I hope you might have seen my problem description and my input

file.

       with reference to my problem details and to my input file, do

you have any idea what is the problem on my side ?

Thank you,

Best Regards, Dinesh Myislamy

On Wed, Jan 27, 2016 at 9:38 AM, Dinesh Myilsamy dineshaero555@gmail.com wrote:

Hi Sir,

Very nice to hear that from you

Did you make change anything in that input file ?

Have seen at other Devc location is it same?

May I know how many cores did you used and your computer configuration

On Wed, Jan 27, 2016 at 8:00 AM, Kevin McGrattan <notifications@github.com

wrote:

I ran the case twice. The results for the first pressure device are identical.

— Reply to this email directly or view it on GitHub https://github.com/firemodels/fds-smv/issues/3398#issuecomment-175283009 .

mcgratta commented 8 years ago 
[mcgratta@burn Test]$ diff backdraft_devc.csv backdraft2_devc.csv
[mcgratta@burn Test]$

The output files from my two runs are identical.

It is difficult to say what is wrong. Maybe your cluster is losing packets, meaning that the MPI messages are corrupted. I can say that your input file is badly designed. It is poor practice to create thin mesh layers with only 6 cells in the vertical direction. In effect, you are maximizing the amount of information this is communicated process to process. You are also maximizing the error associated with using multiple meshes.

MIRROR boundaries should, in general, not be used for LES calculations. There is no symmetry plane in a turbulent flow like this.

Do not use ADIABATIC walls. There is no such thing as an ADIABATIC wall. We only use this parameter for diagnostic purposes.

INIT lines. Why? Why not just simulate the scenario starting from ambient conditions?

Your combustion issues are being addressed in another thread.

Why all the PRESSURE lines? What do you expect to learn from them?

Could you tell me what reference you used to design this calculation? I am interested because I see these mistakes made very often in input files that are sent to us. I do not know the source of the information that is compelling alot of people to do these things.

drjfloyd commented 8 years ago

I don't agree with the statement that adiabatic walls should only be used for diagnostic purposes.

If I am doing a calculation looking at how quickly a smoke layer can drop in a space, the use of adiabatic walls will add a degree of conservatism as it prevents heat removal from the smoke layer (higher temperature means lower density which results in the layer dropping faster).

mcgratta commented 8 years ago

OK -- but if the calculation exhibits erratic behavior, that is one of the things I would eliminate.

sinaparsa75 commented 4 years ago

Dear Sir, I am Dinesh Myilsamy, currently I am working on a project which is based on compartment fire in an under ventilated condition.

OUTLINE OF MY RESEARCH:

Hot unburnt fuel mixtures (at 373 K)  will be present inside a closed compartment and there is an ignition source which is kept at one of the compartment  (Temp. 1500 k at its top surface), when the compartment window is opened the atmospheric air will get into the compartment due to the density difference. Fresh air will start to move inside the compartment and it will reach to the ignition source which is kept at other end of the compartment (opposite to window).

When the fresh air reacts with the unburnt fuel in the presence of ignition source there will be a rapid flame propagation (BACKDRAFT) inside the compartment with and it moves out of the compartment as a fireball.

picture1

          This has to be carried out using LES Turbulence Model and EDC as a combustion Model.

MY ISSUES.

        1.  For my simulation I am using FDS v.6.3.2 in an  Intel Core 2 E8400, 3.0 GHz, 32 Core Cluster. - Linux Operating system.

         I am getting two different solutions when I tried to simulate my  FDS input file. 

         I did not even change a single letter in my FDS file, I used the same computer, using 15 Cores. but I found a two different solution.

press

       2.  To resolve this problem I got a guidance from FDS google group. In that they adviced me to use   NOISE =.FALSE.

          I have tried by specifying NOISE=.FALSE,  NOISE_VELOCITY = 0.005 but the problem didn't get resolved

noise_005

My input parameters

MISC PARAMETERS

& MISC TMPA=25.0, DNS=.FALSE., NOISE=.FALSE., NOISE_VELOCITY=0.005, SUPPRESSION=.FALSE. / & RADI RADIATION=.TRUE./

REAC PARAMETERS

& REAC FUEL='METHANE', SPEC_ID_NU='METHANE','OXYGEN','CARBON DIOXIDE','WATER VAPOR' NU=-1,-2,1,2, SPEC_ID_N_S='METHANE','OXYGEN', A = 5.2E13, N_S= 1,1, HEAT_OF_COMBUSTION = 50240, E = 123980.0 FIXED_MIX_TIME=0.003/

IGNITION SOURCE REACTION TIME

&RAMP ID='N2_V', T= 0.000, F= 0.0 / &RAMP ID='N2_V', T= 3.000, F= 0.0 / &RAMP ID='N2_V', T= 3.500, F= 1.0 / &RAMP ID='N2_V', T= 4.000, F= 0.0 / &RAMP ID='N2_V', T= 10.00, F= 0.0 / / &RAMP ID='N2_T', T= 0.000, F= 0.0 / &RAMP ID='N2_T', T= 3.000, F= 0.0 / &RAMP ID='N2_T', T= 3.500, F= 1.0 / &RAMP ID='N2_T', T= 4.000, F= 0.0 / &RAMP ID='N2_T', T= 10.00, F= 0.0 /

hello Mr.Myilsamy; i'm reading your paper with a title "Large eddy simulation of the backdraft dynamics in compartments with different opening geometries" and i want to use this paper for my validation project. but i dont have some specification. could you send me fds code for case 1 in this paper? please help me for this case. my email: s2_parsa@yahoo.com

mcgratta commented 4 years ago

I need you to do two tasks:

  1. Run your case with the latest released version of FDS.
  2. If you still see multiple solutions, post the input file.
sinaparsa75 commented 4 years ago

I need you to do two tasks:

1. Run your case with the latest released version of FDS.

2. If you still see multiple solutions, post the input file.

Hello Mr.Kevin I ran the code with the latest version. But my Problem exactly with multiple solutions. i have some problem with reaction and ignition source of this paper : https://www.researchgate.net/publication/332830944_Large_eddy_simulation_of_the_backdraft_dynamics_in_compartments_with_different_opening_geometries I'm Trying to learn Backdraft phenomena for case 1 in this paper. Could you help me reproduce the Code form this article? I want to reach same this pictures. thank you.

my code: &HEAD CHID='v2'/ &TIME T_END=15.0, DT=0.01/ &DUMP RENDER_FILE='v2.ge1', COLUMN_DUMP_LIMIT=.TRUE., DT_RESTART=300.0, DT_SL3D=0.25/ &MISC TMPA=25.0, Y_O2_INFTY=0.232379/

&MESH ID='Mesh01', IJK=128,21,43, XB=0.0,3.84,0.0,0.64,0.0,1.28/

&SPEC ID='OXYGEN'/ &SPEC ID='NITROGEN'/ &SPEC ID='CARBON MONOXIDE'/ &SPEC ID='CARBON DIOXIDE'/

&REAC ID='METHANE', FYI='AFT NIST Multi-Floor FDS5 Validation', FUEL='METHANE', CRITICAL_FLAME_TEMPERATURE=4000.0, AUTO_IGNITION_TEMPERATURE=150.0, CO_YIELD=0.015, HEAT_OF_COMBUSTION=5.3E4/

&CTRL ID='invert', FUNCTION_TYPE='ALL', LATCH=.FALSE., INITIAL_STATE=.TRUE., INPUT_ID='TIMER->OUT2'/ &DEVC ID='O2', QUANTITY='MASS FRACTION', SPEC_ID='OXYGEN', XYZ=0.62,0.32,0.32/ &DEVC ID='THCP', QUANTITY='THERMOCOUPLE', XYZ=1.24,0.32,0.32/ &DEVC ID='TIMER->OUT', QUANTITY='TIME', XYZ=0.0,0.0,0.0, SETPOINT=2.85/ &DEVC ID='TIMER->OUT2', QUANTITY='TIME', XYZ=0.0,0.0,0.0, SETPOINT=0.01/

&MATL ID='STEEL2', SPECIFIC_HEAT=0.77, CONDUCTIVITY=45.8, DENSITY=7700.0, EMISSIVITY=0.7/

&SURF ID='ADIABATIC', COLOR='GRAY 80', ADIABATIC=.TRUE./ &SURF ID='STEEL', RGB=226,14,243, TMP_INNER=25.0, BACKING='INSULATED', MATL_ID(1,1)='STEEL2', MATL_MASS_FRACTION(1,1)=1.0, THICKNESS(1)=3.0E-4/ &SURF ID='Surface01', RGB=255,102,0, TMP_FRONT=1500.0/

&INIT ID='Meth', TEMPERATURE=67.0, SPEC_ID='CARBON DIOXIDE','CARBON MONOXIDE','METHANE','NITROGEN','OXYGEN', MASS_FRACTION=0.021,1.2E-3,0.1224,0.7094,0.146, XB=0.02,1.22,0.02,0.62,0.02,0.3/ &INIT ID='Meth U', TEMPERATURE=103.0, SPEC_ID='CARBON DIOXIDE','CARBON MONOXIDE','METHANE','NITROGEN','OXYGEN', MASS_FRACTION=0.021,1.2E-3,0.1224,0.7094,0.146, XB=0.02,1.22,0.02,0.62,0.3,0.62/

&OBST ID='Obstruction', XB=0.0,3.84,0.0,0.64,0.0,0.02, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,0.02,0.02,0.62,0.02,0.62, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,1.24,0.0,0.64,0.62,0.64, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,1.24,0.0,0.02,0.02,0.62, COLOR='INVISIBLE', SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,1.24,0.62,0.64,0.02,0.62, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.02,0.17,0.245,0.395,0.02,0.17, SURF_ID='STEEL'/ &OBST ID='Obstruction', XB=1.23,1.23,0.213333,0.426667,0.029767,0.625116, SURF_ID='ADIABATIC', CTRL_ID='invert'/ &OBST ID='Obstruction', XB=1.23,1.23,0.030476,0.213333,0.029767,0.625116, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=1.23,1.23,0.426667,0.609524,0.029767,0.625116, SURF_ID='ADIABATIC'/

&VENT ID='Mesh Vent: Mesh01 [XMAX]', SURF_ID='OPEN', XB=3.84,3.84,0.0,0.64,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [XMIN]', SURF_ID='OPEN', XB=0.0,0.0,0.0,0.64,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [YMAX]', SURF_ID='OPEN', XB=0.0,3.84,0.64,0.64,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [YMIN]', SURF_ID='OPEN', XB=0.0,3.84,0.0,0.0,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [ZMAX]', SURF_ID='OPEN', XB=0.0,3.84,0.0,0.64,1.28,1.28/ &VENT ID='Vent02', SURF_ID='Surface01', XB=0.02,0.17,0.245,0.395,0.17,0.17, DEVC_ID='TIMER->OUT'/

&SLCF QUANTITY='MASS FRACTION', SPEC_ID='METHANE', PBY=0.32/ &SLCF QUANTITY='TEMPERATURE', PBY=0.32/

&TAIL / 22 33 Capture3333

sinaparsa75 commented 4 years ago

I write another Code with better information... But it didnt work also Code: &HEAD CHID='v2'/ &TIME T_END=15.0, DT=0.01/ &DUMP RENDER_FILE='v2.ge1', COLUMN_DUMP_LIMIT=.TRUE., DT_RESTART=300.0, DT_SL3D=0.25/ &MISC TMPA=25.0, Y_O2_INFTY=0.232379/

&MESH ID='Mesh01', IJK=128,21,43, XB=0.0,3.84,0.0,0.64,0.0,1.28/

&SPEC ID='OXYGEN'/ &SPEC ID='CARBON DIOXIDE'/ &SPEC ID='CARBON MONOXIDE'/ &SPEC ID='NITROGEN'/

&REAC ID='METHANE', FYI='AFT NIST Multi-Floor FDS5 Validation', FUEL='METHANE', CRITICAL_FLAME_TEMPERATURE=3000.0, AUTO_IGNITION_TEMPERATURE=150.0, CO_YIELD=0.015, HEAT_OF_COMBUSTION=5.3E4/

&CTRL ID='invert', FUNCTION_TYPE='ALL', LATCH=.FALSE., INITIAL_STATE=.TRUE., INPUT_ID='TIMER->OUT'/ &DEVC ID='O2', QUANTITY='MASS FRACTION', SPEC_ID='OXYGEN', XYZ=0.62,0.32,0.32/ &DEVC ID='THCP', QUANTITY='THERMOCOUPLE', XYZ=1.24,0.32,0.32/ &DEVC ID='TIMER->OUT', QUANTITY='TIME', XYZ=0.0,0.0,0.0, SETPOINT=0.01/

&MATL ID='STEEL2', SPECIFIC_HEAT=0.77, CONDUCTIVITY=45.8, DENSITY=7700.0, EMISSIVITY=0.7/

&SURF ID='ADIABATIC', COLOR='GRAY 80', ADIABATIC=.TRUE./ &SURF ID='STEEL', RGB=226,14,243, TMP_INNER=25.0, BACKING='INSULATED', MATL_ID(1,1)='STEEL2', MATL_MASS_FRACTION(1,1)=1.0, THICKNESS(1)=3.0E-4/ &SURF ID='Surface01', RGB=239,7,5, TMP_FRONT=1500.0, RAMP_T='Surface01_RAMP_T', VEL=-0.05, RAMP_V='Surface01_RAMP_V', MASS_FRACTION=1.0, SPEC_ID='METHANE', TAU_MF=1.0E-3/ &RAMP ID='Surface01_RAMP_T', T=0.0, F=0.0/ &RAMP ID='Surface01_RAMP_T', T=2.4, F=0.0/ &RAMP ID='Surface01_RAMP_T', T=2.9, F=1.0/ &RAMP ID='Surface01_RAMP_T', T=3.5, F=0.0/ &RAMP ID='Surface01_RAMP_T', T=8.0, F=0.0/ &RAMP ID='Surface01_RAMP_V', T=0.0, F=0.0/ &RAMP ID='Surface01_RAMP_V', T=2.4, F=0.0/ &RAMP ID='Surface01_RAMP_V', T=2.9, F=1.0/ &RAMP ID='Surface01_RAMP_V', T=3.5, F=0.0/ &RAMP ID='Surface01_RAMP_V', T=8.0, F=0.0/

&INIT ID='Meth', TEMPERATURE=67.0, SPEC_ID='CARBON DIOXIDE','CARBON MONOXIDE','METHANE','NITROGEN','OXYGEN', MASS_FRACTION=0.021,1.2E-3,0.1224,0.7094,0.146, XB=0.02,1.22,0.02,0.62,0.02,0.3/ &INIT ID='Meth U', TEMPERATURE=103.0, SPEC_ID='CARBON DIOXIDE','CARBON MONOXIDE','METHANE','NITROGEN','OXYGEN', MASS_FRACTION=0.021,1.2E-3,0.1224,0.7094,0.146, XB=0.02,1.22,0.02,0.62,0.3,0.62/

&OBST ID='Obstruction', XB=0.0,3.84,0.0,0.64,0.0,0.02, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,0.02,0.02,0.62,0.02,0.62, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,1.24,0.0,0.64,0.62,0.64, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,1.24,0.0,0.02,0.02,0.62, COLOR='INVISIBLE', SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.0,1.24,0.62,0.64,0.02,0.62, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=0.02,0.17,0.245,0.395,0.02,0.17, SURF_ID='STEEL'/ &OBST ID='Obstruction', XB=1.23,1.23,0.213333,0.426667,0.029767,0.625116, SURF_ID='ADIABATIC', CTRL_ID='invert'/ &OBST ID='Obstruction', XB=1.23,1.23,0.030476,0.213333,0.029767,0.625116, SURF_ID='ADIABATIC'/ &OBST ID='Obstruction', XB=1.23,1.23,0.426667,0.609524,0.029767,0.625116, SURF_ID='ADIABATIC'/

&VENT ID='Mesh Vent: Mesh01 [XMAX]', SURF_ID='OPEN', XB=3.84,3.84,0.0,0.64,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [XMIN]', SURF_ID='OPEN', XB=0.0,0.0,0.0,0.64,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [YMAX]', SURF_ID='OPEN', XB=0.0,3.84,0.64,0.64,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [YMIN]', SURF_ID='OPEN', XB=0.0,3.84,0.0,0.0,0.0,1.28/ &VENT ID='Mesh Vent: Mesh01 [ZMAX]', SURF_ID='OPEN', XB=0.0,3.84,0.0,0.64,1.28,1.28/ &VENT ID='Vent02', SURF_ID='Surface01', XB=0.02,0.17,0.245,0.395,0.17,0.17/

&SLCF QUANTITY='MASS FRACTION', SPEC_ID='METHANE', PBY=0.32/ &SLCF QUANTITY='TEMPERATURE', PBY=0.32/

&TAIL /

ignition source not burned and i cant see backdraft phenomena please help me to reach a correct Code.

mcgratta commented 4 years ago

Sorry, the purpose of the FDS Issue Tracker is to resolve problems and bugs in FDS. Unless there is something specifically wrong with FDS, we cannot help you. Perhaps you can reach out to the authors of the paper and ask them to share their input files.

sinaparsa75 commented 4 years ago

For your information Hereby I have attached my input file.

Temp_100_FMT_1_00.txt

I cant download this file! could u put it again?