galilean_re_gate Namespace Reference

Functions
	abraham_cd (re)
	make (y0)
	run (moving)

Variables
int	DH = float(sys.argv[1]) if len(sys.argv) > 1 else 8.0
int	RE = float(sys.argv[2]) if len(sys.argv) > 2 else 1.5
int	N = int(sys.argv[3]) if len(sys.argv) > 3 else 96
int	STEPS = int(sys.argv[4]) if len(sys.argv) > 4 else 800
str	ADV = "1"
float	U = 0.02
float	NU = U * DH / RE
float	DT = 3.2
	KI_I
	KI_R
float	OFF = 0.3
float	F_EST = abraham_cd(RE) * 0.5 * U ** 2 * np.pi * (DH / 2) ** 2
float	B = F_EST / N ** 3
	FS
	vS
	bS
	FM
	vM
	bM
int	n4 = STEPS * 3 // 4
	fS
	fM
	uS = vS[-1][1] / (1.0 - np.pi / 6 * DH ** 3 / N ** 3)
float	uM = U + vM[-1][1] / (1.0 - np.pi / 6 * DH ** 3 / N ** 3)
int	re = u * DH / NU
	cd = f / (0.5 * u ** 2 * np.pi * (DH / 2) ** 2)
	gap = abs(fM / fS - 1.0)

Detailed Description

Finite-Re Galilean gate: a sphere FIXED in a uniform stream vs the SAME sphere TOWED through
fluid at rest -- same box, same Re, same dt, same impulsive start, same body force. In a periodic
box a uniform translation is an exact symmetry of the Navier-Stokes equations, so the two force
histories must agree to discretisation error at EVERY step. The fixed case never exercises the
moving-geometry machinery (fresh cells, wall-velocity advection inputs, the time term at a moving
cut wall, rebuild per step); the towed case exercises all of it. Any gap is a moving-geometry
defect, isolated from resolution and from confinement.

Usage: PYTHONPATH=<flow build> python galilean_re_gate.py [DH=8] [Re=1.5] [N=96] [STEPS=800]
Env:   GAL_ADV=0 turns advection off (the Stokes limit, where the old gate lives).

Function Documentation

abraham_cd()

galilean_re_gate.abraham_cd

(

re

)

Definition at line 30 of file galilean_re_gate.py.

make()

galilean_re_gate.make

(

y0

)

Definition at line 34 of file galilean_re_gate.py.

Referenced by run().

run()

galilean_re_gate.run

(

moving

)

Definition at line 58 of file galilean_re_gate.py.

References make(), and mean().

Variable Documentation

DH

int galilean_re_gate.DH = float(sys.argv[1]) if len(sys.argv) > 1 else 8.0

Definition at line 18 of file galilean_re_gate.py.

RE

int galilean_re_gate.RE = float(sys.argv[2]) if len(sys.argv) > 2 else 1.5

Definition at line 19 of file galilean_re_gate.py.

N

int galilean_re_gate.N = int(sys.argv[3]) if len(sys.argv) > 3 else 96

Definition at line 20 of file galilean_re_gate.py.

STEPS

int galilean_re_gate.STEPS = int(sys.argv[4]) if len(sys.argv) > 4 else 800

Definition at line 21 of file galilean_re_gate.py.

ADV

str galilean_re_gate.ADV = "1"

Definition at line 22 of file galilean_re_gate.py.

U

float galilean_re_gate.U = 0.02

Definition at line 23 of file galilean_re_gate.py.

NU

float galilean_re_gate.NU = U * DH / RE

Definition at line 24 of file galilean_re_gate.py.

DT

float galilean_re_gate.DT = 3.2

Definition at line 25 of file galilean_re_gate.py.

KI_I

galilean_re_gate.KI_I

Definition at line 26 of file galilean_re_gate.py.

KI_R

galilean_re_gate.KI_R

Definition at line 26 of file galilean_re_gate.py.

OFF

float galilean_re_gate.OFF = 0.3

Definition at line 27 of file galilean_re_gate.py.

F_EST

float galilean_re_gate.F_EST = abraham_cd(RE) * 0.5 * U ** 2 * np.pi * (DH / 2) ** 2

Definition at line 54 of file galilean_re_gate.py.

B

float galilean_re_gate.B = F_EST / N ** 3

Definition at line 55 of file galilean_re_gate.py.

FS

galilean_re_gate.FS

Definition at line 85 of file galilean_re_gate.py.

vS

galilean_re_gate.vS

Definition at line 85 of file galilean_re_gate.py.

bS

galilean_re_gate.bS

Definition at line 85 of file galilean_re_gate.py.

FM

galilean_re_gate.FM

Definition at line 86 of file galilean_re_gate.py.

vM

galilean_re_gate.vM

Definition at line 86 of file galilean_re_gate.py.

bM

galilean_re_gate.bM

Definition at line 86 of file galilean_re_gate.py.

n4

int galilean_re_gate.n4 = STEPS * 3 // 4

Definition at line 90 of file galilean_re_gate.py.

fS

galilean_re_gate.fS

Definition at line 91 of file galilean_re_gate.py.

fM

galilean_re_gate.fM

Definition at line 91 of file galilean_re_gate.py.

uS

galilean_re_gate.uS = vS[-1][1] / (1.0 - np.pi / 6 * DH ** 3 / N ** 3)

Definition at line 92 of file galilean_re_gate.py.

uM

float galilean_re_gate.uM = U + vM[-1][1] / (1.0 - np.pi / 6 * DH ** 3 / N ** 3)

Definition at line 93 of file galilean_re_gate.py.

re

int galilean_re_gate.re = u * DH / NU

Definition at line 99 of file galilean_re_gate.py.

cd

galilean_re_gate.cd = f / (0.5 * u ** 2 * np.pi * (DH / 2) ** 2)

Definition at line 100 of file galilean_re_gate.py.

gap

galilean_re_gate.gap = abs(fM / fS - 1.0)

Definition at line 105 of file galilean_re_gate.py.