Add support for generating a D3Q19 kernel

Note how this basically required no changes besides generalizing cell indexing
and adding the symbolic formulation of a D3Q19 BGK collision step.

Increasing the neighborhood communication from 9 to 19 cells leads to a
significant performance "regression": The 3D kernel yields ~ 360 MLUPS
compared to the 2D version's ~ 820 MLUPS.

1 files changed, 0 insertions, 79 deletions

diff --git a/lid_driven_cavity.py b/lid_driven_cavity.py
deleted file mode 100644
index 873adeb..0000000
--- a/lid_driven_cavity.py
+++ /dev/null
@@ -1,79 +0,0 @@
-import numpy
-import time
-
-import matplotlib
-import matplotlib.pyplot as plt
-matplotlib.use('AGG')
-
-from lbm import Lattice, Geometry
-
-import symbolic.D2Q9 as D2Q9
-
-def MLUPS(cells, steps, time):
-    return cells * steps / time * 1e-6
-
-def generate_moment_plots(lattice, moments):
-    for i, m in enumerate(moments):
-        print("Generating plot %d of %d." % (i+1, len(moments)))
-
-        velocity = numpy.ndarray(shape=tuple(reversed(lattice.geometry.inner_span())))
-        for x, y in lattice.geometry.inner_cells():
-            velocity[y-1,x-1] = numpy.sqrt(m[1,lattice.idx(x,y)]**2 + m[2,lattice.idx(x,y)]**2)
-
-        plt.figure(figsize=(10, 10))
-        plt.imshow(velocity, origin='lower', cmap=plt.get_cmap('seismic'))
-        plt.savefig("result/ldc_" + str(i) + ".png", bbox_inches='tight', pad_inches=0)
-
-def cavity(geometry, x, y):
-    if x == 1 or y == 1 or x == geometry.size_x-2:
-        return 2
-    elif y == geometry.size_y-2:
-        return 3
-    else:
-        return 1
-
-boundary = """
-    if ( m == 2 ) {
-        u_0 = 0.0;
-        u_1 = 0.0;
-    }
-    if ( m == 3 ) {
-        u_0 = 0.1;
-        u_1 = 0.0;
-    }
-"""
-
-nUpdates = 100000
-nStat    = 5000
-
-moments = []
-
-print("Initializing simulation...\n")
-
-lattice = Lattice(
-    descriptor = D2Q9,
-    geometry   = Geometry(256, 256),
-
-    moments = D2Q9.moments(optimize = False),
-    collide = D2Q9.bgk(tau = 0.56),
-
-    boundary_src = boundary)
-
-lattice.setup_geometry(cavity)
-
-print("Starting simulation using %d cells...\n" % lattice.geometry.volume)
-
-lastStat = time.time()
-
-for i in range(1,nUpdates+1):
-    lattice.evolve()
-
-    if i % nStat == 0:
-        lattice.sync()
-        print("i = %4d; %3.0f MLUPS" % (i, MLUPS(lattice.geometry.volume, nStat, time.time() - lastStat)))
-        moments.append(lattice.get_moments())
-        lastStat = time.time()
-
-print("\nConcluded simulation.\n")
-
-generate_moment_plots(lattice, moments)