4.2.7. Adaptation Options

The “Adaptation” section of pyCart.json except for the one that tells pyCart whether or not to run adaptively. Below is a sample section of pyCart.json that contains the default values for the relevant options.

"Adaptation": {
    "n_adapt_cycles": 0,
    "etol": 0.000001,
    "max_nCells": 50000000,
    "ws_it": [50, 50],
    "mesh_growth": [1.5, 1.5, 2.0, 2.0, 2.0, 2.0, 2.5],
    "apc": ["p", "a"],
    "abuff": 1,
    "final_mesh_xref": 0
}

The full description of these options is given in the list below. Most of these options are almost exactly analogous to the similarly named variables in aero.csh.

n_adapt_cycles: {0} | int | list (int)

Number of adaptation cycles to run

etol: {0.000001} | float

Target error tolerance. The adaptation cycles will terminate if this error level (in absolute value) in the output function is reached.

max_nCells: {50000000} | int

Maximum number of volume mesh cells. If an adaptation results in more cells than this number, analysis terminates.

ws_it: {[50, 50]} | list (int)

Number of flowCart iterations to run during each adaptation cycle. When setting up adaptation cycles, pyCart assumes the last entry in this list is repeated indefinitely.

mesh_growth: list (float)

Mesh growth factor for each adaptation cycle. The volume mesh will increase the number of volume cells by approximately this number after a given adaptation cycle. When setting up adaptation cycles, pyCart assumes that the last entry in this list is repeated indefinitely.

apc: {["p", "a"]} | list ("p" | "a")

Sets whether each adaptation cycle is a propagate (“p”) cycle or adapt (“a”) cycle. Propagate cycles cannot decrease the size of the smallest cell. When setting up adaptation cycles, pyCart assumes that the last entry in this list is repeated indefinitely.

abuff: {1} | int | list (int)

Number of buffer layers to use when refining a mesh. Increasing this parameter decreases the size of the smallest clump of cells that can be refined. Increasing it results in less targeted refinement.

final_mesh_xref: {0} | int

Number of extra refinements to compute using the final error map. New adjoints are not computed for these additional xref adaptations.