Darcy-Weisbach friction models

[piyueh]

Changes

1. Six Darcy-Weisbach friction models

Six different ways to assign or calculate Darcy-Weisbach coefficients are provided. Use DarcyWeisbachData.type to set the type (see setrun.py in examples):

• type = 0: No Darcy-Weisbach friction. Use GeoClaw's original Manning's friction.
• type = 1: assign a constant coefficient everywhere in the domain. Required subsequent parameter:
  • coefficient: (float) the coefficients of the blocks
• type = 2: assign blockwise constants. The followings are parameters required when choosing this type:
  • n_blocks: (integer) number of blocks
  • xlowers: (list) x coords of the lower corners of the blocks
  • xuppers: (list) x coords of the upper corners of the blocks
  • ylowers: (list) y coords of the lower corners of the blocks
  • yuppers: (list) y coords of the upper corners of the blocks
  • coefficients: (list) the coefficients of the blocks
  • default_coefficient: (float) the coefficient for areas that are not covered by the blocks
• type = 3: cell-wise varying coefficients. Parameters:
  • `filename': (string) an Esri ASCII file for coefficients
  • default_coefficient: (float) the coefficient for areas not covered by the file.
• type = 4: calculate the coefficients on the fly based on local Reynolds numbers and local roughness. We use a three-regime model (analytical solution, Blasius eq., and Swamee & Jain approx. for laminar, transient, and turbulence, respectively) for the coefficients. Parameters:
  • filename: (string) an Esri ASCII file for roughness data
  • default_roughness: (float) roughness for areas not covered by the file
• type = 5: the same as type = 4, except that we use Churchill's model to calculate the coefficients.
• type = 6: the same as type =5, except a two-regime model is used: 1) for the laminar regime, we use analytical solution, and 2) for both transition and turbulence regimes, we solve the Colebrook-White formula directly. This means the performance will be somehow worse than other types because we solve the formula iteratively for each cell. The reason for this type is to do validations against some literature.

2. A roughness.txt in Utah example

There is a new file called roughness.txt in the Utah example. But since there's no data for roughness in the real case, so the roughness data is fake.

3. A new example: silicon oil on an inclined plane, 2.5 degree

This example simulates silicon oil flow with a point source on an inclined plane which has an angle of 2.5 degrees. The simulation results can be compared with the experimental data from Lister (1992).

4. Setting kinematic viscosity of working fluids in setrun.py

Some Darcy-Weisbach models require the viscosity of the working fluids, so users can now set the value in setrun.py. The kinematic viscosity will be read into geoclaw_module.

5. A new docker file for this pull request (PR9)

[piyueh]

Hi @mandli, this is a new PR for a new feature: Darcy-Weisbach frictions. I'm wondering if you could review it when you have time? Thank you very much!!

The docker file for this PR is Dockerfile-PR9. And there's an image in our DockerHub repo with the tag PR9.

[mandli]

I am in the midst of the review but one thing that caught my attention was that you seem to be reimplementing a significant amount of functionality for reading in solutions and plotting them. This is not inherently bad but I am wondering what functionality the clawpack.pyclaw.solution.Solution does not contain that you need.

[piyueh]

Thanks for the information! I didn't realize I can use PyClaw for the solution I/O. I can definitely use the API in PyClaw for post-processing. Given the tight schedule of this project, however, I think I'll have to leave this task to the future after required functionalities are implemented in the flow solver.

The plotting scripts are very specific to each example and are not designed to be used outside those examples. So I guess it's okay to keep them there for now and migrate to PyClaw API in the future for better integration into the Clawpack ecosystem.

[mandli]

@piyueh Have not forgotten about this, just happens to be midterms around here and I have been tied up with a bunch of deadlines. This isn't blocking you on any other improvements is it?

[piyueh]

No worries! This is non-blocking PR. Thank you!

[mandli]

@piyueh This can be merged whenever at this point I would say.

[piyueh]

@mandli Got it! Thank you!! The remaining issues are addressed in Issue #11 and #12 .