"No Functor ever provided with name 'dh_dt' under 'T_time' FVKernel" even though I listed the parameter

[waaizhaq]

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Question

Hello,

I am trying to conduct a simple natural convection problem in MOOSE, as shown below.

My mesh only consists of the natural circulation flow, so the width of the wall is neglected. I just set a left boundary condition of Ts, and made my mesh thickness 1 meter.

I am very new to MOOSE so I am still learning how to use it. I've been following a lot of examples posted online in the framework to create my input file, so do let me know if something seems out of place.

But an error I've been running into is the 'dh_dt' not being provided even though I listed it under the INSFVEnergyTImeDerivative kernel. Is there something else that I'm missing?

I also tried running this problem as a steady state by commenting out the time-dependent kernels and changing the executioner type to steady, but then I got an error about the solve not converging.

By the way, to run this input I copied the navier stokes module into my own separate directory and compiled it, following the instructions that were in the framework under 'Pre-Built MOOSE.'

Additional information

Mesh size and type: rectangular mesh, 5 by 5
Discretization (finite element CG/DG, finite volume, etc): finite volume
Models (turbulence, porous media, etc): natural convection
Base input you started from: nat_conv_wall.txt

[GiudGiud]

Hello

This functor has to be defined by a FunctorMaterial. Here it should be this one:
https://mooseframework.inl.gov/source/functormaterials/INSFVEnthalpyFunctorMaterial.html

[waaizhaq]

That fixed it, thank you! I'm unfamiliar with the way MOOSE solves its simulations. Do you have any resources I can read into to understand the numerical methods of the different solvers?

[GiudGiud]

You ll have to look to the PETSc documentation for how the nonlinear system is solved. MOOSE does the assembly then calls petsc

[waaizhaq]

If I wanted to run the simulation as steady-state, which parameters would I change? I've commented out the time-dependent kernels and also the TimeStepper block under the Executioner block, then changed Transient to Steady, but then I run into another DIVERGED_DTOL convergence issue, I also added automatic_scaling in my executioner block.

Framework Information:
MOOSE Version: git commit 2bd11a0 on 2024-10-06
LibMesh Version:
PETSc Version: 3.21.5
SLEPc Version: 3.21.1
Current Time: Sun Dec 15 19:53:48 2024
Executable Timestamp: Sun Oct 6 04:10:42 2024

Checkpoint:
Wall Time Interval: Every 3600 s
User Checkpoint: Disabled

Checkpoints Kept: 2

Execute On: TIMESTEP_END

Parallelism:
Num Processors: 1
Num Threads: 1

Mesh:
Parallel Type: replicated
Mesh Dimension: 2
Spatial Dimension: 2
Nodes: 36
Elems: 25
Num Subdomains: 1

Nonlinear System:
Num DOFs: 100
Num Local DOFs: 100
Variables: { "vel_x" "vel_y" "pressure" "T" }
Finite Element Types: "MONOMIAL"
Approximation Orders: "CONSTANT"

Execution Information:
Executioner: Steady
Solver Mode: NEWTON
PETSc Preconditioner: lu
MOOSE Preconditioner: SMP (auto)

Postprocessor Values:
+----------------+----------------+
| time | ave_T |
+----------------+----------------+
| 0.000000e+00 | 0.000000e+00 |
+----------------+----------------+

Performing automatic scaling calculation

0 Nonlinear |R| = 8.303678e+03
0 Linear |R| = 8.303678e+03
1 Linear |R| = 1.000718e-10
1 Nonlinear |R| = 3.338182e+08
0 Linear |R| = 3.338182e+08
1 Linear |R| = 8.988101e-04
2 Nonlinear |R| = 9.164821e+07
0 Linear |R| = 9.164821e+07
1 Linear |R| = 6.644202e-08
3 Nonlinear |R| = 2.058075e+07
0 Linear |R| = 2.058075e+07
1 Linear |R| = 1.044626e-08
4 Nonlinear |R| = 5.263572e+06
0 Linear |R| = 5.263572e+06
1 Linear |R| = 4.649094e-09
5 Nonlinear |R| = 1.930216e+06
0 Linear |R| = 1.930216e+06
1 Linear |R| = 2.490749e-09
6 Nonlinear |R| = 2.454784e+06
0 Linear |R| = 2.454784e+06
1 Linear |R| = 4.081857e-08
7 Nonlinear |R| = 1.965131e+09
0 Linear |R| = 1.965131e+09
1 Linear |R| = 1.977286e-06
8 Nonlinear |R| = 5.999012e+05
0 Linear |R| = 5.999012e+05
1 Linear |R| = 1.087908e-06
9 Nonlinear |R| = 6.960520e+05
0 Linear |R| = 6.960520e+05
1 Linear |R| = 1.075856e-08
10 Nonlinear |R| = 1.063886e+06
0 Linear |R| = 1.063886e+06
1 Linear |R| = 3.278389e-09
11 Nonlinear |R| = 5.422805e+08
0 Linear |R| = 5.422805e+08
1 Linear |R| = 4.369014e-07
12 Nonlinear |R| = 7.352211e+06
0 Linear |R| = 7.352211e+06
1 Linear |R| = 3.356987e-06
13 Nonlinear |R| = 4.169012e+09
0 Linear |R| = 4.169012e+09
1 Linear |R| = 1.430620e-06
14 Nonlinear |R| = 9.723472e+09
0 Linear |R| = 9.723472e+09
1 Linear |R| = 1.466204e-03
15 Nonlinear |R| = 7.599592e+11
0 Linear |R| = 7.599592e+11
1 Linear |R| = 6.276364e-03
16 Nonlinear |R| = 1.370462e+13
0 Linear |R| = 1.370462e+13
1 Linear |R| = 5.705603e+00
17 Nonlinear |R| = 1.451590e+16
Nonlinear solve did not converge due to DIVERGED_DTOL iterations 17
Solve Did NOT Converge!
Aborting as solve did not converge

[GiudGiud]

For steady state (without using a relaxation transient) you need to work on the initialization. The initial condition needs to fall in the region of attraction of the solution, which can be hard to do

It's generally easier to use a relaxation-to-steady state transient

[waaizhaq]

I understand, I think that's what I have for my transient case, where it runs the simulation until it reaches steady state.