Added sophistaced test

lbmpy_tests/test_boundary_handling.py

@@ -112,6 +112,122 @@ def test_simple(target):
     assert (all(dh.cpu_arrays['pdfs'][0, 2:4, 8] == 5))
 
 
+@pytest.mark.parametrize("given_normal", [True, False])
+def test_free_slip(given_normal):
+    # check if Free slip BC is applied correctly
+
+    stencil = LBStencil(Stencil.D2Q9)
+    dh = create_data_handling(domain_size=(4, 4),)
+    src1 = dh.add_array('src1', values_per_cell=stencil.Q)
+    dh.fill('src1', 0.0, ghost_layers=True)
+
+    shape = dh.gather_array('src1', ghost_layers=True).shape
+
+    num = 0
+    for x in range(shape[0]):
+        for y in range(shape[1]):
+            for direction in range(shape[2]):
+                dh.cpu_arrays[src1.name][x, y, direction] = num
+                num += 1
+
+    method = create_lb_method(lbm_config=LBMConfig(stencil=stencil, method=Method.SRT, relaxation_rate=1.8))
+
+    bh = LatticeBoltzmannBoundaryHandling(method, dh, 'src1', name="bh1")
+    if given_normal:
+        free_slipN = FreeSlip(stencil=stencil, normal_direction=(0, -1))
+        free_slipS = FreeSlip(stencil=stencil, normal_direction=(0, 1))
+        free_slipE = FreeSlip(stencil=stencil, normal_direction=(-1, 0))
+        free_slipW = FreeSlip(stencil=stencil, normal_direction=(1, 0))
+
+        bh.set_boundary(free_slipN, slice_from_direction('N', dh.dim))
+        bh.set_boundary(free_slipS, slice_from_direction('S', dh.dim))
+        bh.set_boundary(free_slipE, slice_from_direction('E', dh.dim))
+        bh.set_boundary(free_slipW, slice_from_direction('W', dh.dim))
+    else:
+        free_slip = FreeSlip(stencil=stencil)
+
+        bh.set_boundary(free_slip, slice_from_direction('N', dh.dim))
+        bh.set_boundary(free_slip, slice_from_direction('S', dh.dim))
+        bh.set_boundary(free_slip, slice_from_direction('E', dh.dim))
+        bh.set_boundary(free_slip, slice_from_direction('W', dh.dim))
+
+    bh()
+
+    mirrored_dirN = {6: 8, 1: 2, 5: 7}
+    mirrored_dirS = {7: 5, 2: 1, 8: 6}
+    mirrored_dirE = {6: 5, 4: 3, 8: 7}
+    mirrored_dirW = {5: 6, 3: 4, 7: 8}
+
+    # check North
+    assert dh.cpu_arrays[src1.name][1, -1, mirrored_dirN[6]] == dh.cpu_arrays[src1.name][1, -2, 6]
+    assert dh.cpu_arrays[src1.name][1, -1, mirrored_dirN[1]] == dh.cpu_arrays[src1.name][1, -2, 1]
+
+    for i in range(2, 4):
+        assert dh.cpu_arrays[src1.name][i, -1, mirrored_dirN[6]] == dh.cpu_arrays[src1.name][i, -2, 6]
+        assert dh.cpu_arrays[src1.name][i, -1, mirrored_dirN[1]] == dh.cpu_arrays[src1.name][i, -2, 1]
+        assert dh.cpu_arrays[src1.name][i, -1, mirrored_dirN[5]] == dh.cpu_arrays[src1.name][i, -2, 5]
+
+    assert dh.cpu_arrays[src1.name][4, -1, mirrored_dirN[1]] == dh.cpu_arrays[src1.name][4, -2, 1]
+    assert dh.cpu_arrays[src1.name][4, -1, mirrored_dirN[5]] == dh.cpu_arrays[src1.name][4, -2, 5]
+
+    # check East
+    assert dh.cpu_arrays[src1.name][-1, 1, mirrored_dirE[6]] == dh.cpu_arrays[src1.name][-2, 1, 6]
+    assert dh.cpu_arrays[src1.name][-1, 1, mirrored_dirE[4]] == dh.cpu_arrays[src1.name][-2, 1, 4]
+
+    for i in range(2, 4):
+        assert dh.cpu_arrays[src1.name][-1, i, mirrored_dirE[6]] == dh.cpu_arrays[src1.name][-2, i, 6]
+        assert dh.cpu_arrays[src1.name][-1, i, mirrored_dirE[4]] == dh.cpu_arrays[src1.name][-2, i, 4]
+        assert dh.cpu_arrays[src1.name][-1, i, mirrored_dirE[8]] == dh.cpu_arrays[src1.name][-2, i, 8]
+
+    assert dh.cpu_arrays[src1.name][-1, 4, mirrored_dirE[4]] == dh.cpu_arrays[src1.name][-2, 4, 4]
+    assert dh.cpu_arrays[src1.name][-1, 4, mirrored_dirE[8]] == dh.cpu_arrays[src1.name][-2, 4, 8]
+
+    # check South
+    assert dh.cpu_arrays[src1.name][1, 0, mirrored_dirS[8]] == dh.cpu_arrays[src1.name][1, 1, 8]
+    assert dh.cpu_arrays[src1.name][1, 0, mirrored_dirS[2]] == dh.cpu_arrays[src1.name][1, 1, 2]
+
+    for i in range(2, 4):
+        assert dh.cpu_arrays[src1.name][i, 0, mirrored_dirS[7]] == dh.cpu_arrays[src1.name][i, 1, 7]
+        assert dh.cpu_arrays[src1.name][i, 0, mirrored_dirS[2]] == dh.cpu_arrays[src1.name][i, 1, 2]
+        assert dh.cpu_arrays[src1.name][i, 0, mirrored_dirS[8]] == dh.cpu_arrays[src1.name][i, 1, 8]
+
+    assert dh.cpu_arrays[src1.name][4, 0, mirrored_dirS[2]] == dh.cpu_arrays[src1.name][4, 1, 2]
+    assert dh.cpu_arrays[src1.name][4, 0, mirrored_dirS[7]] == dh.cpu_arrays[src1.name][4, 1, 7]
+
+    # check West
+    assert dh.cpu_arrays[src1.name][0, 1, mirrored_dirW[5]] == dh.cpu_arrays[src1.name][1, 1, 5]
+    assert dh.cpu_arrays[src1.name][0, 1, mirrored_dirW[3]] == dh.cpu_arrays[src1.name][1, 1, 3]
+
+    for i in range(2, 4):
+        assert dh.cpu_arrays[src1.name][0, i, mirrored_dirW[5]] == dh.cpu_arrays[src1.name][1, i, 5]
+        assert dh.cpu_arrays[src1.name][0, i, mirrored_dirW[3]] == dh.cpu_arrays[src1.name][1, i, 3]
+        assert dh.cpu_arrays[src1.name][0, i, mirrored_dirW[7]] == dh.cpu_arrays[src1.name][1, i, 7]
+
+    assert dh.cpu_arrays[src1.name][0, 4, mirrored_dirW[3]] == dh.cpu_arrays[src1.name][1, 4, 3]
+    assert dh.cpu_arrays[src1.name][0, 4, mirrored_dirW[7]] == dh.cpu_arrays[src1.name][1, 4, 7]
+
+    if given_normal:
+        # check corners --> determined by the last boundary applied there.
+        # SouthWest --> West
+        assert dh.cpu_arrays[src1.name][0, 0, mirrored_dirW[5]] == dh.cpu_arrays[src1.name][1, 0, 5]
+        # NorthWest --> West
+        assert dh.cpu_arrays[src1.name][0, -1, mirrored_dirW[7]] == dh.cpu_arrays[src1.name][1, -1, 7]
+        # NorthEast --> East
+        assert dh.cpu_arrays[src1.name][-1, -1, mirrored_dirE[8]] == dh.cpu_arrays[src1.name][-2, -1, 8]
+        # SouthEast --> East
+        assert dh.cpu_arrays[src1.name][-1, 0, mirrored_dirE[6]] == dh.cpu_arrays[src1.name][-2, 0, 6]
+    else:
+        # check corners --> this time the normals are calculated correctly in the corners
+        # SouthWest --> Normal = (1, 1); dir 7 --> 6
+        assert dh.cpu_arrays[src1.name][0, 0, 6] == dh.cpu_arrays[src1.name][1, 1, 7]
+        # NorthWest --> Normal = (1, -1); dir 8 --> 5
+        assert dh.cpu_arrays[src1.name][0, -1, 8] == dh.cpu_arrays[src1.name][1, -2, 5]
+        # NorthEast --> Normal = (-1, -1); dir 7 --> 6
+        assert dh.cpu_arrays[src1.name][-1, -1, 7] == dh.cpu_arrays[src1.name][-2, -2, 6]
+        # SouthEast --> Normal = (-1, 1); dir 5 --> 8
+        assert dh.cpu_arrays[src1.name][-1, 0, 5] == dh.cpu_arrays[src1.name][-2, 1, 8]
+
+
 def test_free_slip_index_list():
     stencil = LBStencil(Stencil.D2Q9)
     dh = create_data_handling(domain_size=(4, 4), periodicity=(False, False))
@@ -214,7 +330,7 @@ def test_free_slip_equivalence():
     bh1()
     bh2()
 
-    assert np.array_equal(dh.cpu_arrays['src1'], dh.cpu_arrays['src2'])
+    assert np.array_equal(dh.gather_array('src1'), dh.gather_array('src2'))
 
 
 def test_exotic_boundaries():