[hridu]

hello..

i tried to simulate 2D rectangular box in NWT(CFD)
after sometime it showing EMERGENCY STOP -- velocities exceeding critical value N 61
what is the error?
how the error occured?

control.txt
C 11 6
C 12 3
C 13 3
C 14 7
C 15 21
C 16 3
B 1 0.02
B 10 0.0 25.0 0.0 0.8 0.0 0.8
M 10 2
M 20 2

ctrl.txt
A 10 6
B 10 1
B 50 0.001
B 90 1
B 92 4
B 93 0.07 1.7
B 94 0.5
B 96 2.0 4.0
B 98 2
B 99 2
C 10 3
C 15 4
C 20 2
D 10 4
D 20 2
D 30 1
F 10 2
F 30 3
F 35 5
F 40 3
F 42 1.0
F 60 0.5
G 60 12.3 12.7 0.01 0.78 0.367 0.567
I 10 1
I 11 1
I 12 1
I 13 1
I 30 1
N 10 14
N 11 11
N 40 3
N 41 60
N 47 0.3
M 10 2
P 10 1
P 14 1
P 23 1
P 25 1
P 26 1
P 27 1
P 28 1
P 29 1
P 30 0.1
P 40 1
P 42 1.0
P 52 0.01
P 53 1
P 54 100
P 55 0.1
P 51 6.0 0.01
P 51 9.0 0.01
P 51 15.0 0.01
P 51 20.0 0.01
T 10 2
T 11 11
T 12 5
T 41 1
W 1 1000
W 22 -9.81
X 10 1
X 11 1 0 1 0 1 0
X 12 1
X 13 2
X 15 2
X 19 1
X 22 5.22
X 50 2
X 110 12.3 12.7 0.01 0.78 0.367 0.567

please tell me why this happend?

[soydana]

Since your domain size along the y-direction is 0.8 and mesh size 0.02, this is not a 2-D simulation, 3-D instead.

Use the control files attached then should be okay.

control.txt

ctrl.txt

[hridu]

Originally Posted by soydana

Since your domain size along the y-direction is 0.8 and mesh size 0.02, this is not a 2-D simulation, 3-D instead.

Use the control files attached then should be okay.

Attachment 95670

Attachment 95671

So this input is for 2D simulation?


if i want to simulate in 3D what will be the inputs?
can you show the 3D input example of the above?
how the domain y and floating body y axis change?
i need help...........................

[soydana]

Originally Posted by hridu

So this input is for 2D simulation?


if i want to simulate in 3D what will be the inputs?
can you show the 3D input example of the above?
how the domain y and floating body y axis change?
i need help...........................

Yes, these files are for 2D simulation. To make it 3D, just change the domain size along the y-direction(B10 command in contol.txt file) and the box coordinates along the y-direction (X 110 command in ctrl.txt file).

Let's say your box width is 0.2 meters then your control files should be as attached.

control.txt

ctrl.txt

[hridu]

Originally Posted by soydana

Yes, these files are for 2D simulation. To make it 3D, just change the domain size along the y-direction(B10 command in contol.txt file) and the box coordinates along the y-direction (X 110 command in ctrl.txt file).

Let's say your box width is 0.2 meters then your control files should be as attached.

Attachment 95672

Attachment 95673

from the ctrl.txt
you wrote x 11 1 0 1 0 1 0 is it for 3dof right?

For 6DOF X 11 1 1 1 1 1 1 ??
What is the input for 6dof?

[hridu]

Originally Posted by soydana

Since your domain size along the y-direction is 0.8 and mesh size 0.02, this is not a 2-D simulation, 3-D instead.

Use the control files attached then should be okay.

Attachment 95670

Attachment 95671

505
simtime: 0.468
timestep: 2.44e-05
fbtimestep: 5.22e-06 fbmax: 6.61e+07
t/T: 0.275
Volume 1: 0.0495
Volume 2: 0.351
lsmtime: 0.0502
kin_iter: 8 kin_time: 0.0717
omega_iter: 7 omega_time: 0.0731
Inflow: 0 Ui: 0 Hi: 0.5
Outflow: 0 Uo: 0 Ho: 0.5
Hydrodynamic Forces: Fx_p: 7263.8 Fy_p: 0 Fz_p: 3.8202e+06 | Fx_v: -1.0694e-07 Fy_v: 0 Fz_v: 0.00082357
Xe: 7263.8 Ye: 0 Ze: 3.8202e+06 Ke: -0.038906 Me: -13448 Ne: 0.012071
.piter: 5 ptime: 0.0363
Pressure splitting error = 0.00413
Hydrodynamic Forces: Fx_p: 6.34e+03 Fy_p: 0 Fz_p: 4e+06 | Fx_v: -4.98e-07 Fy_v: 0 Fz_v: 0.000827
Xe: 6.34e+03 Ye: 0 Ze: 4e+06 Ke: -0.0325 Me: -1.1e+04 Ne: 0.0137
.piter: 5 ptime: 0.0377
Pressure splitting error = 0.0164
Hydrodynamic Forces: Fx_p: 5.84e+03 Fy_p: 0 Fz_p: 4e+06 | Fx_v: -1.16e-06 Fy_v: 0 Fz_v: 0.00083
Xe: 5.84e+03 Ye: 0 Ze: 4e+06 Ke: -0.03 Me: -1.02e+04 Ne: 0.0117
XG: 12.5 YG: 0.01 ZG: 0.119 phi: 1.08e-12 theta: 0.0933 psi: -1.61e-14
Ue: -0.364 Ve: 0 We: -5.09 Pe: -4.57e-10 Qe: -39.6 Re: -3.02e-12
.piter: 5 ptime: 0.0389
Pressure splitting error = 0.00652
umax: 3.99 utime: 0.0497
vmax: 0 vtime: 0.00143
wmax: 75.2 wtime: 0.0659
viscmax: 5.83
kinmax: 6.65e+03
epsmax: 4.37e+03
wavegentime: 0.0115
fbtime: 0.538
reinitime: 0.0688
gctime: 0.434 average gctime: 0.447
Xtime: 0.0278 average Xtime: 0.0303
total time: 792.663 average time: 1.57
timer per step: 1.49

EMERGENCY STOP -- velocities exceeding critical value N 61

same error after simulating your inputs that you given....
now what is the reason for this EMERGENCY STOP -- velocities exceeding critical value N 61??

[soydana]

Originally Posted by hridu

505
simtime: 0.468
timestep: 2.44e-05
fbtimestep: 5.22e-06 fbmax: 6.61e+07
t/T: 0.275
Volume 1: 0.0495
Volume 2: 0.351
lsmtime: 0.0502
kin_iter: 8 kin_time: 0.0717
omega_iter: 7 omega_time: 0.0731
Inflow: 0 Ui: 0 Hi: 0.5
Outflow: 0 Uo: 0 Ho: 0.5
Hydrodynamic Forces: Fx_p: 7263.8 Fy_p: 0 Fz_p: 3.8202e+06 | Fx_v: -1.0694e-07 Fy_v: 0 Fz_v: 0.00082357
Xe: 7263.8 Ye: 0 Ze: 3.8202e+06 Ke: -0.038906 Me: -13448 Ne: 0.012071
.piter: 5 ptime: 0.0363
Pressure splitting error = 0.00413
Hydrodynamic Forces: Fx_p: 6.34e+03 Fy_p: 0 Fz_p: 4e+06 | Fx_v: -4.98e-07 Fy_v: 0 Fz_v: 0.000827
Xe: 6.34e+03 Ye: 0 Ze: 4e+06 Ke: -0.0325 Me: -1.1e+04 Ne: 0.0137
.piter: 5 ptime: 0.0377
Pressure splitting error = 0.0164
Hydrodynamic Forces: Fx_p: 5.84e+03 Fy_p: 0 Fz_p: 4e+06 | Fx_v: -1.16e-06 Fy_v: 0 Fz_v: 0.00083
Xe: 5.84e+03 Ye: 0 Ze: 4e+06 Ke: -0.03 Me: -1.02e+04 Ne: 0.0117
XG: 12.5 YG: 0.01 ZG: 0.119 phi: 1.08e-12 theta: 0.0933 psi: -1.61e-14
Ue: -0.364 Ve: 0 We: -5.09 Pe: -4.57e-10 Qe: -39.6 Re: -3.02e-12
.piter: 5 ptime: 0.0389
Pressure splitting error = 0.00652
umax: 3.99 utime: 0.0497
vmax: 0 vtime: 0.00143
wmax: 75.2 wtime: 0.0659
viscmax: 5.83
kinmax: 6.65e+03
epsmax: 4.37e+03
wavegentime: 0.0115
fbtime: 0.538
reinitime: 0.0688
gctime: 0.434 average gctime: 0.447
Xtime: 0.0278 average Xtime: 0.0303
total time: 792.663 average time: 1.57
timer per step: 1.49

EMERGENCY STOP -- velocities exceeding critical value N 61

same error after simulating your inputs that you given....
now what is the reason for this EMERGENCY STOP -- velocities exceeding critical value N 61??

Which REEF3D version are you using? It works for me with the latest version.

And for 6 DOF yes, X 11 1 1 1 1 1 1.

[hridu]

Originally Posted by soydana

Which REEF3D version are you using? It works for me with the latest version.

And for 6 DOF yes, X 11 1 1 1 1 1 1.

REEFED 23.03
DIVEMESH 23.03
Hypre 2.27
Eigen 3.4

please tell me what is the reason now?

[soydana]

Originally Posted by hridu

REEFED 23.03
DIVEMESH 23.03
Hypre 2.27
Eigen 3.4

please tell me what is the reason now?

Can you use the latest release candidate of REEF3D? Then it will work.

[hridu]

[QUOTE=soydana;854811]Can you use the latest release candidate of REEF3D? Then it will work.

solved the issue.....thank you