CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Programming & Development

Different results between 3 processors simulation and 7 processors simulation

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree1Likes
  • 1 Post By mfmohdyasin

Reply
 
LinkBack Thread Tools Display Modes
Old   August 27, 2012, 03:26
Default Different results between 3 processors simulation and 7 processors simulation
  #1
New Member
 
fairus
Join Date: Apr 2010
Posts: 20
Rep Power: 7
mfmohdyasin is on a distinguished road
Dear all,

I added the following line in parcel.C file. (after the last line of updateParcelProperties member function)

Info << " d() = " << d() << endl;

Then I run dieselFoam with 3 decompositions and got the following output in log file:
Evolving Spray
d() = 1.12798e-05
d() = 1.12798e-05
d() = 1.57086e-05
d() = 1.57086e-05
d() = 1.54595e-05
.....
....
Solving chemistry
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 0.00170744, Final residual = 4.95922e-07, No Iterations 5
DILUPBiCG: Solving for Uy, Initial residual = 0.00181109, Final residual = 3.96033e-07, No Iterations 5
DILUPBiCG: Solving for Uz, Initial residual = 0.000120342, Final residual = 1.81973e-07, No Iterations 4
DILUPBiCG: Solving for C7H16, Initial residual = 0.820013, Final residual = 9.75537e-07, No Iterations 8
DILUPBiCG: Solving for O2, Initial residual = 0.000302092, Final residual = 3.62254e-07, No Iterations 3
DILUPBiCG: Solving for CO2, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for H2O, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for h, Initial residual = 0.000105396, Final residual = 4.97253e-07, No Iterations 3
DICPCG: Solving for p, Initial residual = 0.19397, Final residual = 8.81985e-10, No Iterations 58
DICPCG: Solving for p, Initial residual = 9.91074e-10, Final residual = 9.91074e-10, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.28234e-13, global = -2.93383e-14, cumulative = -2.93383e-14
DICPCG: Solving for p, Initial residual = 0.0156706, Final residual = 9.4495e-10, No Iterations 56
DICPCG: Solving for p, Initial residual = 9.90869e-10, Final residual = 9.90869e-10, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.2799e-13, global = 3.14686e-14, cumulative = 2.13031e-15
DILUPBiCG: Solving for epsilon, Initial residual = 0.002522, Final residual = 7.4453e-07, No Iterations 4
DILUPBiCG: Solving for k, Initial residual = 0.000132955, Final residual = 6.47361e-07, No Iterations 3

Number of parcels in system.... | 50
Injected liquid mass........... | 27.9464 mg
Liquid Mass in system.......... | 0.00560216 mg
SMD, Dmax...................... | 16.8812 mu, 53.4697 mu
Added gas mass................. | 27.9408 mg
Evaporation Continuity Error... | 4.44956e-06 mg
ExecutionTime = 1.21 s ClockTime = 1 s
However, when I run with 7 decompositions I got the following:
Evolving Spray
Solving chemistry
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 0.00153395, Final residual = 4.14953e-07, No Iterations 5
DILUPBiCG: Solving for Uy, Initial residual = 0.00163918, Final residual = 3.44191e-07, No Iterations 5
DILUPBiCG: Solving for Uz, Initial residual = 9.21614e-05, Final residual = 6.42257e-07, No Iterations 3
DILUPBiCG: Solving for C7H16, Initial residual = 0.828965, Final residual = 5.45344e-07, No Iterations 10
DILUPBiCG: Solving for O2, Initial residual = 0.000294897, Final residual = 4.85681e-07, No Iterations 3
DILUPBiCG: Solving for CO2, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for H2O, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for h, Initial residual = 9.22275e-05, Final residual = 4.16487e-07, No Iterations 3
DICPCG: Solving for p, Initial residual = 0.184617, Final residual = 7.51892e-10, No Iterations 59
DICPCG: Solving for p, Initial residual = 0.0012862, Final residual = 9.94569e-10, No Iterations 47
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.33238e-13, global = -5.25939e-15, cumulative = -5.25939e-15
DICPCG: Solving for p, Initial residual = 0.010484, Final residual = 9.81269e-10, No Iterations 53
DICPCG: Solving for p, Initial residual = 0.000409979, Final residual = 9.88064e-10, No Iterations 44
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.32206e-13, global = 2.41525e-14, cumulative = 1.88931e-14
DILUPBiCG: Solving for epsilon, Initial residual = 0.00246708, Final residual = 4.9188e-07, No Iterations 4
bounding epsilon, min: -9.6188 max: 2.27937e+07 average: 31722.1
DILUPBiCG: Solving for k, Initial residual = 8.8404e-05, Final residual = 5.15251e-07, No Iterations 3

Number of parcels in system.... | 59
Injected liquid mass........... | 27.9464 mg
Liquid Mass in system.......... | 0.00657278 mg
SMD, Dmax...................... | 16.638 mu, 53.4697 mu
Added gas mass................. | 27.9408 mg
Evaporation Continuity Error... | 0.000977339 mg
ExecutionTime = 0.79 s ClockTime = 1 s
The lines with "d()" is not shown any more in 7 processors simulation.

Any idea why this happened?

Fairus
mfmohdyasin is offline   Reply With Quote

Old   August 27, 2012, 04:07
Default
  #2
New Member
 
fairus
Join Date: Apr 2010
Posts: 20
Rep Power: 7
mfmohdyasin is on a distinguished road
Just figured out that I supposed to use "Pout" instead of "Info" to get output from each processor. Now, for 3 processors, I got the following:
Evolving Spray
[0] d() = 1.12798e-05
[0] d() = 1.12798e-05
[0] d() = 1.57086e-05
[0] d() = 1.57086e-05
[0] d() = 1.54595e-05
[0] d() = 1.54595e-05
[0] d() = 1.8351e-05
[0] d() = 1.8351e-05
[0] d() = 1.99194e-05
.....
....
....
Solving chemistry
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 0.0014768, Final residual = 1.15586e-07, No Iterations 6
DILUPBiCG: Solving for Uy, Initial residual = 0.00138362, Final residual = 6.95235e-07, No Iterations 5
DILUPBiCG: Solving for Uz, Initial residual = 5.60855e-05, Final residual = 9.75065e-07, No Iterations 3
DILUPBiCG: Solving for C7H16, Initial residual = 0.114131, Final residual = 5.25429e-07, No Iterations 7
DILUPBiCG: Solving for O2, Initial residual = 0.000130773, Final residual = 7.78804e-07, No Iterations 3
DILUPBiCG: Solving for CO2, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for H2O, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for h, Initial residual = 0.000274324, Final residual = 4.24009e-07, No Iterations 3
DICPCG: Solving for p, Initial residual = 0.0512225, Final residual = 7.91496e-10, No Iterations 56
DICPCG: Solving for p, Initial residual = 8.46768e-10, Final residual = 8.46768e-10, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.0986e-13, global = 1.1918e-14, cumulative = 1.40483e-14
DICPCG: Solving for p, Initial residual = 0.0107209, Final residual = 7.19084e-10, No Iterations 53
DICPCG: Solving for p, Initial residual = 7.75078e-10, Final residual = 7.75078e-10, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.00267e-13, global = 4.93066e-15, cumulative = 1.8979e-14
DILUPBiCG: Solving for epsilon, Initial residual = 0.00250506, Final residual = 8.27057e-07, No Iterations 4
bounding epsilon, min: -7211.69 max: 2.28754e+07 average: 31824.2
DILUPBiCG: Solving for k, Initial residual = 0.000115688, Final residual = 7.84806e-07, No Iterations 3
And I got the following with 7 processors:
Evolving Spray
[2] d() = 1.12798e-05
[2] d() = 1.12798e-05
[2] d() = 1.57086e-05
[2] d() = 1.57086e-05
[2] d() = 1.54595e-05
[2] d() = 1.54595e-05
[2] d() = 1.8351e-05
[2] d() = 1.8351e-05
[2] d() = 1.99194e-05
[2] d() = 1.99194e-05
[1] d() = 1.99194e-05
......
......
......
Solving chemistry
[2] d() = 3.20949e-05
[2] d() = 3.20949e-05
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 0.00153395, Final residual = 4.14953e-07, No Iterations 5
DILUPBiCG: Solving for Uy, Initial residual = 0.00163918, Final residual = 3.44191e-07, No Iterations 5
DILUPBiCG: Solving for Uz, Initial residual = 9.21614e-05, Final residual = 6.42257e-07, No Iterations 3
DILUPBiCG: Solving for C7H16, Initial residual = 0.828965, Final residual = 5.45344e-07, No Iterations 10
DILUPBiCG: Solving for O2, Initial residual = 0.000294897, Final residual = 4.85681e-07, No Iterations 3
DILUPBiCG: Solving for CO2, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for H2O, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for h, Initial residual = 9.22275e-05, Final residual = 4.16487e-07, No Iterations 3
DICPCG: Solving for p, Initial residual = 0.184617, Final residual = 7.51892e-10, No Iterations 59
DICPCG: Solving for p, Initial residual = 0.0012862, Final residual = 9.94569e-10, No Iterations 47
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.33238e-13, global = -5.25939e-15, cumulative = -5.25939e-15
DICPCG: Solving for p, Initial residual = 0.010484, Final residual = 9.81269e-10, No Iterations 53
DICPCG: Solving for p, Initial residual = 0.000409979, Final residual = 9.88064e-10, No Iterations 44
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.32206e-13, global = 2.41525e-14, cumulative = 1.88931e-14
DILUPBiCG: Solving for epsilon, Initial residual = 0.00246708, Final residual = 4.9188e-07, No Iterations 4
bounding epsilon, min: -9.6188 max: 2.27937e+07 average: 31722.1
DILUPBiCG: Solving for k, Initial residual = 8.8404e-05, Final residual = 5.15251e-07, No Iterations 3

Apparently, 3 processors decomposition employs a serial calculation for lagrangian particle tracking and 7 processors decomposition employs 2 processors for lagrangian particle tracking. That's why "Info" works for 3 processors decomposition and not for 7 processors decomposition (please correct me if I'm wrong).

Good lesson on Monday morning .

Fairus
wyldckat likes this.
mfmohdyasin is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
CFX Varying time-step and Results freequency jstaylor89 Main CFD Forum 0 April 16, 2012 11:14
Comparison of 2D simulation results with 3D Mohit Gupta Main CFD Forum 0 September 29, 2008 13:04
Detached Eddy Simulation Maged Ismail Main CFD Forum 4 June 10, 2005 08:28
Gravity g's influence on Simulation Results Colin Main CFD Forum 6 November 2, 2003 15:13
graphical handling of simulation results yf yap Main CFD Forum 3 February 12, 2001 20:35


All times are GMT -4. The time now is 11:37.