pore_doublet Namespace Reference

Classes
class	Health

Functions
	box2d (px, pz, xlo, xhi, zlo, zhi)
	doublet_sdf ()
	build (theta_deg, U, momentum=True, slip=0.0)
	_run_end (mask)
	fronts (C, eps)
	run (theta_deg, ca, steps, sample_every, label, momentum=True, budget=None, slip=0.0)
	main ()

Variables
	NX
	NY
	PLEN_IN
	BRANCH
	PLEN_OUT
	W_NARROW
	W_WIDE
	Z_WALL_BOT
	Z_SEPT
	Z_WALL_TOP
float	WALL_SHIFT = 0.25
	NZ = Z_WALL_BOT + W_WIDE + Z_SEPT + W_NARROW + Z_WALL_TOP
	X1
	X2
	ZW_LO
	ZW_HI
	ZN_LO
	ZN_HI
float	SIGMA = 100.0
	RHO_L
	RHO_G
	MU_L
	MU_G
float	CAP_CFL = 0.5
int	PRESS_CAP = 400
str	NPY_DIR = ""
int	PRESS_RTOL = 1e-8
int	MG_LEVELS = 5
int	VEL_SWEEPS = 20

Detailed Description

WO-V7 case 1 — the PORE DOUBLET: which branch fills first, and when.

Two straight channels of width `w` and `2w` leave a common inlet plenum and rejoin in a common
outlet plenum.  Liquid is injected at the inlet face at a fixed uniform velocity `U`; the doublet
is gas-filled at t = 0.  The question is the classical one (Chatzis & Dullien, *J. Can. Pet.
Tech.* 22:97, 1983; Moore & Slobod 1956): **which branch does the liquid fill first?**

    capillary-dominated (Ca -> 0), WETTING invasion (theta < 90):  the NARROW branch, because the
        driving capillary pressure 2 sigma cos(theta)/w is larger there;
    capillary-dominated, NON-WETTING invasion (theta > 90):  the WIDE branch, because the
        *resisting* entry pressure |2 sigma cos(theta)|/w is smaller there;
    viscous-dominated (Ca -> large):  the WIDE branch in BOTH cases, because a slit's hydraulic
        conductance goes as w^3.

So the wetting sweep is the discriminating one: it must INVERT between low and high Ca, while the
non-wetting sweep must NOT (both limits pick the wide branch).

CONVENTIONS AND CAVEATS, stated on every run (WO-V7 preamble):
  * the contact angle is the STATIC V5b fill.  The V6 dynamic angle is qualitative until V6b adds
    the velocity-side Navier slip, so the capillary numbers below are **apparent**: they are
    mu_l * U_inlet / sigma with U_inlet the prescribed superficial inlet velocity, not a measured
    contact-line speed.
  * density ratio 100.  Higher is not rated: V2b's uniform-velocity identity is floored at 1.2e-7
    by the solver's FLOAT momentum-operator storage, and WO-R's G3 gas-over-pool caveat (a pool at
    ratio 1000 picks up 3e-2 of the inlet speed) is unresolved.
  * no periodic net body force anywhere (VOF_PLAN 13.2 item 6): the drive is an inflow/outflow pair.
  * the solid is kept clear of the inflow and outflow planes (flow's open-BC/cut-cell defect,
    `doc/cutcell_openbc_convergence.md`).
  * a run whose pressure solve touches its cap is INVALID and is reported as such (rule 3b).

Usage:
    PYTHONPATH=$PWD/build_cuda python tests/study/pore_scale/pore_doublet.py [--quick]
                                     [--theta 45,135] [--ca 1e-4,1e-3,1e-2]

Function Documentation

box2d()

pore_doublet.box2d	(		px,
			pz,
			xlo,
			xhi,
			zlo,
			zhi
	)

Exact signed distance (outside) to an axis-aligned box in the (x, z) plane.

Definition at line 77 of file pore_doublet.py.

Referenced by doublet_sdf().

doublet_sdf()

pore_doublet.doublet_sdf

(

)

> 0 in the fluid (flow's convention).  Three solid boxes, all clear of x = 0 and x = NX.

Definition at line 86 of file pore_doublet.py.

References box2d().

Referenced by build().

build()

pore_doublet.build	(		theta_deg,
			U,
			momentum = True,
			slip = 0.0
	)

Definition at line 122 of file pore_doublet.py.

References doublet_sdf().

_run_end()

pore_doublet._run_end (   mask )

protected

Length of the run of True that starts at index 0 (0 if the first entry is False).

Definition at line 165 of file pore_doublet.py.

Referenced by fronts().

fronts()

pore_doublet.fronts	(		C,
			eps
	)

Two front positions per branch, in cells from the branch entrance X1, plus the branch
liquid saturation.

`tip`  the leading edge: the last x, contiguous from the entrance, at which ANY cell of the
       cross-section is more than half liquid.
`bar`  the cross-section-AVERAGED front: the last x, contiguous from the entrance, at which the
       openness-weighted mean colour of the cross-section exceeds a half.

Both are reported because they differ by the length of the meniscus, and that length scales
with the CHANNEL WIDTH: at theta = 135 the meniscus in the 32-cell branch is about twice as
long as in the 16-cell one, so `bar` alone carries a systematic bias of order w/2 in favour of
the NARROW branch.  Breakthrough is declared on `tip`, which has no such bias.

Definition at line 171 of file pore_doublet.py.

References _run_end().

Referenced by run().

run()

pore_doublet.run	(		theta_deg,
			ca,
			steps,
			sample_every,
			label,
			momentum = True,
			budget = None,
			slip = 0.0
	)

Definition at line 198 of file pore_doublet.py.

References fronts().

Referenced by main().

main()

pore_doublet.main

(

)

Definition at line 338 of file pore_doublet.py.

References main(), and run().

Referenced by main().

Variable Documentation

NX

pore_doublet.NX

Definition at line 48 of file pore_doublet.py.

NY

pore_doublet.NY

Definition at line 48 of file pore_doublet.py.

PLEN_IN

pore_doublet.PLEN_IN

Definition at line 49 of file pore_doublet.py.

BRANCH

pore_doublet.BRANCH

Definition at line 49 of file pore_doublet.py.

PLEN_OUT

pore_doublet.PLEN_OUT

Definition at line 49 of file pore_doublet.py.

W_NARROW

pore_doublet.W_NARROW

Definition at line 50 of file pore_doublet.py.

W_WIDE

pore_doublet.W_WIDE

Definition at line 50 of file pore_doublet.py.

Z_WALL_BOT

pore_doublet.Z_WALL_BOT

Definition at line 51 of file pore_doublet.py.

Z_SEPT

pore_doublet.Z_SEPT

Definition at line 51 of file pore_doublet.py.

Z_WALL_TOP

pore_doublet.Z_WALL_TOP

Definition at line 51 of file pore_doublet.py.

WALL_SHIFT

float pore_doublet.WALL_SHIFT = 0.25

Definition at line 59 of file pore_doublet.py.

NZ

pore_doublet.NZ = Z_WALL_BOT + W_WIDE + Z_SEPT + W_NARROW + Z_WALL_TOP

Definition at line 60 of file pore_doublet.py.

X1

pore_doublet.X1

Definition at line 61 of file pore_doublet.py.

X2

pore_doublet.X2

Definition at line 61 of file pore_doublet.py.

ZW_LO

pore_doublet.ZW_LO

Definition at line 62 of file pore_doublet.py.

ZW_HI

pore_doublet.ZW_HI

Definition at line 62 of file pore_doublet.py.

ZN_LO

pore_doublet.ZN_LO

Definition at line 63 of file pore_doublet.py.

ZN_HI

pore_doublet.ZN_HI

Definition at line 63 of file pore_doublet.py.

SIGMA

float pore_doublet.SIGMA = 100.0

Definition at line 66 of file pore_doublet.py.

RHO_L

pore_doublet.RHO_L

Definition at line 67 of file pore_doublet.py.

RHO_G

pore_doublet.RHO_G

Definition at line 67 of file pore_doublet.py.

MU_L

pore_doublet.MU_L

Definition at line 68 of file pore_doublet.py.

MU_G

pore_doublet.MU_G

Definition at line 68 of file pore_doublet.py.

CAP_CFL

float pore_doublet.CAP_CFL = 0.5

Definition at line 69 of file pore_doublet.py.

PRESS_CAP

int pore_doublet.PRESS_CAP = 400

Definition at line 70 of file pore_doublet.py.

NPY_DIR

str pore_doublet.NPY_DIR = ""

Definition at line 71 of file pore_doublet.py.

PRESS_RTOL

int pore_doublet.PRESS_RTOL = 1e-8

Definition at line 72 of file pore_doublet.py.

MG_LEVELS

int pore_doublet.MG_LEVELS = 5

Definition at line 73 of file pore_doublet.py.

VEL_SWEEPS

int pore_doublet.VEL_SWEEPS = 20

Definition at line 74 of file pore_doublet.py.