Functions
	sphere_radius (phi, N)

	sc_sdf (N, phi)

	drag_K (umean, R, N, f, mu)

	run (N, phi, mode, vel_iter=200, vlevels=4, vcycles=12, mu=0.1, f=1e-3, dt=60.0, max_steps=600, tol=1e-7)

	main ()

	mu_b (dt, mu=0.1)

Variables
list	ZH_PHI = [0.000125, 0.001, 0.008, 0.027, 0.064, 0.125, 0.216, 0.343, 0.45, 0.5236]

list	ZH_K = [1.096, 1.212, 1.525, 2.008, 2.810, 4.292, 7.442, 15.4, 28.1, 42.1]

Detailed Description

Z&H gate for the STAIRCASE velocity-MG coarse operator (IBM momentum solve).

Simple-cubic sphere array (the Zick & Homsy Stokes-drag ground truth). The IBM velocity diffusion is solved
with plain RB-GS (the exact reference) vs the staircase velocity multigrid (set_velocity_multigrid): the fine
level is the sharp row-based IBM stencil, the coarse levels use the volume fraction only to CLASSIFY cells
(theta>=0.5 fluid / <0.5 solid-pinned) and a plain const-coeff Helmholtz at fluid cells, with the IBM-cell
residuals filtered before restriction. See doc/velocity_mg_plan.md.

Two checks:
  (1) drag: |K_vmg - K_rbgs| / K_rbgs < 0.1% at a fixed V-cycle budget;
  (2) stiff stability: at a large dt (beta=nu*dt=80) where the old geometry-blind const coarse op diverged,
      the staircase stays finite and exact.

Function Documentation

◆ sphere_radius()

verify_velocity_mg_staircase_zh_sdflow.sphere_radius	(	phi,
		N
	)

Definition at line 29 of file verify_velocity_mg_staircase_zh_sdflow.py.

Referenced by sc_sdf().

◆ sc_sdf()

verify_velocity_mg_staircase_zh_sdflow.sc_sdf	(	N,
		phi
	)

Definition at line 33 of file verify_velocity_mg_staircase_zh_sdflow.py.

References sphere_radius().

Referenced by run().

◆ drag_K()

verify_velocity_mg_staircase_zh_sdflow.drag_K	(	umean,
		R,
		N,
		f,
		mu
	)

Definition at line 41 of file verify_velocity_mg_staircase_zh_sdflow.py.

Referenced by run().

◆ run()

verify_velocity_mg_staircase_zh_sdflow.run	(	N,
		phi,
		mode,
		vel_iter = `200`,
		vlevels = `4`,
		vcycles = `12`,
		mu = `0.1`,
		f = `1e-3`,
		dt = `60.0`,
		max_steps = `600`,
		tol = `1e-7`
	)

mode: 'rbgs' (plain RB-GS reference) | 'vmg' (the staircase velocity-MG, via set_velocity_multigrid).

Definition at line 45 of file verify_velocity_mg_staircase_zh_sdflow.py.

References drag_K(), and sc_sdf().

Referenced by main().

◆ main()

verify_velocity_mg_staircase_zh_sdflow.main ( )

Definition at line 73 of file verify_velocity_mg_staircase_zh_sdflow.py.

References run().

Referenced by mu_b().

◆ mu_b()

verify_velocity_mg_staircase_zh_sdflow.mu_b	(	dt,
		mu = `0.1`
	)

Definition at line 101 of file verify_velocity_mg_staircase_zh_sdflow.py.

References main().

Variable Documentation

◆ ZH_PHI

list verify_velocity_mg_staircase_zh_sdflow.ZH_PHI = [0.000125, 0.001, 0.008, 0.027, 0.064, 0.125, 0.216, 0.343, 0.45, 0.5236]

Definition at line 25 of file verify_velocity_mg_staircase_zh_sdflow.py.

◆ ZH_K

list verify_velocity_mg_staircase_zh_sdflow.ZH_K = [1.096, 1.212, 1.525, 2.008, 2.810, 4.292, 7.442, 15.4, 28.1, 42.1]

Definition at line 26 of file verify_velocity_mg_staircase_zh_sdflow.py.

Functions

Variables