rayleigh_taylor Namespace Reference

Functions
	hydrostatic (ratio, mu=0.0, steps=100, g=0.1, dt=1.0, N=8, NZ=24)
	rayleigh_taylor (N=48, NZ=96, g=0.005, mu=0.002, dt=1.0, steps=240)

Variables
	m
	perr
	hist = rayleigh_taylor()
	growth = hist[-1] / hist[0]

Detailed Description

Variable-density validation (Phase 5): hydrostatic acid tests + Rayleigh-Taylor demonstrator.

1. Hydrostatic balance (the acid test): a stratified two-layer fluid at rest under gravity must
   STAY at rest, with the discrete pressure gradient exactly rho_face*g. This detects any
   inconsistency between the momentum face density, the body-force face value, and the projection
   face coefficient. Inviscid: max steady velocity ~1e-16, P-gradient error ~1e-16 at density
   ratios 3 AND 1000. (The C++ ctest `vardensity_projection` runs the same case.)

2. Rayleigh-Taylor: heavy over light (ratio 3, Atwood 0.5) through the FULL two-phase chain — a
   TRANSPORTED phase fraction c drives rho via a linear-mixture closure (auto-enabling the
   variable-density path), gravity is a closure force_z = -g*rho, momentum + projection carry the
   variable density. The interface amplitude grows ~exponentially then nonlinearly; the measured
   early growth rate is ~0.74x the inviscid sqrt(A g k) (viscous + finite-interface damping).

Run:  PYTHONPATH=<build> python rayleigh_taylor.py

Function Documentation

hydrostatic()

rayleigh_taylor.hydrostatic	(		ratio,
			mu = 0.0,
			steps = 100,
			g = 0.1,
			dt = 1.0,
			N = 8,
			NZ = 24
	)

Definition at line 22 of file rayleigh_taylor.py.

rayleigh_taylor()

rayleigh_taylor.rayleigh_taylor	(		N = 48,
			NZ = 96,
			g = 0.005,
			mu = 0.002,
			dt = 1.0,
			steps = 240
	)

Definition at line 44 of file rayleigh_taylor.py.

Variable Documentation

m

rayleigh_taylor.m

Definition at line 76 of file rayleigh_taylor.py.

perr

rayleigh_taylor.perr

Definition at line 76 of file rayleigh_taylor.py.

hist

rayleigh_taylor.hist = rayleigh_taylor()

Definition at line 79 of file rayleigh_taylor.py.

growth

rayleigh_taylor.growth = hist[-1] / hist[0]

Definition at line 80 of file rayleigh_taylor.py.