diff options
Diffstat (limited to 'src/simple.py')
| -rw-r--r-- | src/simple.py | 183 |
1 files changed, 73 insertions, 110 deletions
diff --git a/src/simple.py b/src/simple.py index b54cd38..0e103ea 100644 --- a/src/simple.py +++ b/src/simple.py @@ -27,120 +27,89 @@ class SIMPLE: self.d_n = np.zeros(shape=self.v.shape, dtype=float) self.b = np.zeros(shape=shape, dtype=float) - def allocate_field(self, random=False): - if random: - return np.random.rand(*self.shape) - return np.zeros(shape=self.shape, dtype=float) - - def apply_inflow_boundary(self): - for i in range(1, self.shape[0] - 1): - self.u_star[i][0] = 1 - self.v_star[i][0] = 0 - - def apply_outflow_boundary(self): - for i in range(0, self.shape[0]): - self.u_star[i][-1] = self.u_star[i][-2]; - def assert_positive(self, value): '''Assert that the value is nearly positive''' - assert value > -1, f'WARNING: Value must be positive: {value}' + assert value > -0.01, f'WARNING: Value must be positive: {value}' return value - def grid(self): - '''Iterator over all grid points, excluding the obstacle''' - for i in range(1, self.shape[0] - 1): - for j in range(1, self.shape[1] - 1): - # if i > self.bfs_node_size[0] or j > self.bfs_node_size[1]: - yield (i, j) - def solve_momentum_equations(self): # Momentum along X direction for i in range(1, self.u.shape[0] - 1): for j in range(1, self.u.shape[1] - 1): - u_W = 0.5 * (self.u[i][j] + self.u[i][j - 1]) - u_E = 0.5 * (self.u[i][j] + self.u[i][j + 1]) + if i >= self.bfs_shape[0] or j >= self.bfs_shape[1]: + u_W = 0.5 * (self.u[i][j] + self.u[i][j - 1]) + u_E = 0.5 * (self.u[i][j] + self.u[i][j + 1]) - v_S = 0.5 * (self.v[i][j - 1] + self.v[i][j]) - v_N = 0.5 * (self.v[i + 1][j - 1] + self.v[i + 1][j]) + v_S = 0.5 * (self.v[i][j - 1] + self.v[i][j]) + v_N = 0.5 * (self.v[i + 1][j - 1] + self.v[i + 1][j]) - a_E = self.assert_positive(-0.5 * u_E * self.step + self.nu) - a_W = self.assert_positive(+0.5 * u_W * self.step + self.nu) - a_N = self.assert_positive(-0.5 * v_N * self.step + self.nu) - a_S = self.assert_positive(+0.5 * v_S * self.step + self.nu) + a_E = self.assert_positive(-0.5 * u_E * self.step + self.nu) + a_W = self.assert_positive(+0.5 * u_W * self.step + self.nu) + a_N = self.assert_positive(-0.5 * v_N * self.step + self.nu) + a_S = self.assert_positive(+0.5 * v_S * self.step + self.nu) - a_e = 0.5 * self.step * (u_E - u_W + v_N - v_S) + 4 * self.nu - A_e = -self.step + a_e = 0.5 * self.step * (u_E - u_W + v_N - v_S) + 4 * self.nu + A_e = -self.step - self.d_e[i][j] = A_e / a_e + self.d_e[i][j] = A_e / a_e - self.u_star[i][j] = ( - a_E * self.u[i][j + 1] + - a_W * self.u[i][j - 1] + - a_N * self.u[i + 1][j] + - a_S * self.u[i - 1][j] - ) / a_e + self.d_e[i][j] * (self.p_star[i][j - 1] - self.p_star[i][j]) # p - p_e + self.u_star[i][j] = ( + a_E * self.u[i][j + 1] + + a_W * self.u[i][j - 1] + + a_N * self.u[i + 1][j] + + a_S * self.u[i - 1][j] + ) / a_e + self.d_e[i][j] * (self.p_star[i][j - 1] - self.p_star[i][j]) # p - p_e # Momentum along Y direction for i in range(1, self.v.shape[0] - 1): for j in range(1, self.v.shape[1] - 1): - u_W = 0.5 * (self.u[i - 1][j] + self.u[i][j]) - u_E = 0.5 * (self.u[i - 1][j + 1] + self.u[i][j + 1]) - - v_N = 0.5 * (self.v[i][j] + self.v[i + 1][j]) - v_S = 0.5 * (self.v[i][j] + self.v[i - 1][j]) - - a_E = self.assert_positive(-0.5 * u_E * self.step + self.nu) - a_W = self.assert_positive(+0.5 * u_W * self.step + self.nu) - a_N = self.assert_positive(-0.5 * v_N * self.step + self.nu) - a_S = self.assert_positive(+0.5 * v_S * self.step + self.nu) - - a_n = 0.5 * self.step * (u_E - u_W + v_N - v_S) + 4 * self.nu - A_n = -self.step - - self.d_n[i][j] = A_n / a_n - - self.v_star[i][j] = ( - a_E * self.v[i][j + 1] + - a_W * self.v[i][j - 1] + - a_N * self.v[i + 1][j] + - a_S * self.v[i - 1][j] - ) / a_n + self.d_n[i][j] * (self.p_star[i - 1][j] - self.p_star[i][j]) # p - p_n - - def apply_sides_boundary(self): - for j in range(self.shape[1]): - self.v_star[0][j] = 0 - self.v_star[-2][j] = 0 - # WORKSNICE: self.v_star[-3][j] = 0 - - def apply_bfs_boundary(self): - '''Apply Backwards Facing Step boundary conditions''' - for i in range(self.bfs_node_size[0]): - self.u_star[i][self.bfs_node_size[1]] = 0 - for j in range(self.bfs_node_size[1]): - self.v_star[self.bfs_node_size[0]][j] = 0 + if i >= self.bfs_shape[0] or j >= self.bfs_shape[1]: + u_W = 0.5 * (self.u[i - 1][j] + self.u[i][j]) + u_E = 0.5 * (self.u[i - 1][j + 1] + self.u[i][j + 1]) + + v_N = 0.5 * (self.v[i][j] + self.v[i + 1][j]) + v_S = 0.5 * (self.v[i][j] + self.v[i - 1][j]) + + a_E = self.assert_positive(-0.5 * u_E * self.step + self.nu) + a_W = self.assert_positive(+0.5 * u_W * self.step + self.nu) + a_N = self.assert_positive(-0.5 * v_N * self.step + self.nu) + a_S = self.assert_positive(+0.5 * v_S * self.step + self.nu) + + a_n = 0.5 * self.step * (u_E - u_W + v_N - v_S) + 4 * self.nu + A_n = -self.step + + self.d_n[i][j] = A_n / a_n + + self.v_star[i][j] = ( + a_E * self.v[i][j + 1] + + a_W * self.v[i][j - 1] + + a_N * self.v[i + 1][j] + + a_S * self.v[i - 1][j] + ) / a_n + self.d_n[i][j] * (self.p_star[i - 1][j] - self.p_star[i][j]) # p - p_n def correct_pressure(self): self.p_prime = np.zeros(shape=self.p.shape, dtype=float) for i in range(1, self.p.shape[0] - 1): for j in range(1, self.p.shape[1] - 1): - a_E = 0 if j == self.p.shape[1] - 1 else self.assert_positive(-self.d_e[i][j] * self.step) - a_W = 0 if j == 1 else self.assert_positive(-self.d_e[i][j+1] * self.step) - a_N = 0 if i == self.p.shape[0] - 1 else self.assert_positive(-self.d_n[i+1][j] * self.step) - a_S = 0 if i == 1 else self.assert_positive(-self.d_n[i][j] * self.step) - a_P = a_E + a_W + a_N + a_S - - self.b[i][j] = self.step * ( - -(self.u_star[i][j] - self.u_star[i][j+1]) - + (self.v_star[i+1][j] - self.v_star[i][j]) - ) - - self.p_prime[i][j] = ( - (a_E * self.p_prime[i][j+1] if a_E > 0 else 0) + - (a_W * self.p_prime[i][j-1] if a_W > 0 else 0) + - (a_N * self.p_prime[i+1][j] if a_N > 0 else 0) + - (a_S * self.p_prime[i-1][j] if a_S > 0 else 0) + - self.b[i][j] - ) / a_P + if i >= self.bfs_shape[0] or j >= self.bfs_shape[1]: + a_E = 0 if j == self.p.shape[1] - 1 else self.assert_positive(-self.d_e[i][j] * self.step) + a_W = 0 if j == 1 else self.assert_positive(-self.d_e[i][j+1] * self.step) + a_N = 0 if i == self.p.shape[0] - 1 else self.assert_positive(-self.d_n[i+1][j] * self.step) + a_S = 0 if i == 1 else self.assert_positive(-self.d_n[i][j] * self.step) + a_P = a_E + a_W + a_N + a_S + + self.b[i][j] = self.step * ( + -(self.u_star[i][j] - self.u_star[i][j+1]) + + (self.v_star[i+1][j] - self.v_star[i][j]) + ) + + self.p_prime[i][j] = ( + (a_E * self.p_prime[i][j+1] if a_E > 0 else 0) + + (a_W * self.p_prime[i][j-1] if a_W > 0 else 0) + + (a_N * self.p_prime[i+1][j] if a_N > 0 else 0) + + (a_S * self.p_prime[i-1][j] if a_S > 0 else 0) + + self.b[i][j] + ) / a_P self.p = self.p_star + self.p_prime * self.alpha self.p_star = self.p @@ -158,37 +127,31 @@ class SIMPLE: self.solve_momentum_equations() # Boundary - self.u_star[:, 0] = -self.u_star[:, 1] + self.u_star[:, 0] = 2 - self.u_star[:, 1] self.v_star[:, 0] = 0 - self.u_star[:, -1] = -self.u_star[:, -2] - self.v_star[:, -1] = 0 + self.v_star[-2, :] = -self.v_star[-1, :] + self.v_star[1, :] = -self.v_star[0, :] - self.u_star[-1, :] = 1 - self.v_star[-1, :] = -self.v_star[-2, :] + self.v_star[self.bfs_shape[0], :self.bfs_shape[1]] = self.v_star[self.bfs_shape[0] - 1, :self.bfs_shape[1]] + self.u_star[:self.bfs_shape[0], self.bfs_shape[1]] = self.u_star[:self.bfs_shape[0], self.bfs_shape[1] - 1] - self.u_star[0, :] = 0 - self.v_star[0, :] = -self.v_star[1, :] - - self.p_star[0, 0] = 0 + self.p_star[:self.bfs_shape[0], :self.bfs_shape[1]] = 0 self.correct_pressure() self.correct_velocities() # Boundary enforce - self.u[:, 0] = -self.u[:, 1] + self.u[:, 0] = 2 - self.u[:, 1] self.v[:, 0] = 0 - self.u[:, -1] = -self.u[:, -2] - self.v[:, -1] = 0 - - self.u[-1, :] = 1 - self.v[-1, :] = -self.v[-2, :] + self.v[-2, :] = -self.v[-1, :] + self.v[1, :] = -self.v[0, :] - self.u[0, :] = 0 - self.v[0, :] = -self.v[1, :] + self.v[self.bfs_shape[0], :self.bfs_shape[1]] = self.v[self.bfs_shape[0] - 1, :self.bfs_shape[1]] + self.u[:self.bfs_shape[0], self.bfs_shape[1]] = self.u[:self.bfs_shape[0], self.bfs_shape[1] - 1] - self.p[0, 0] = 0 + self.p[:self.bfs_shape[0], :self.bfs_shape[1]] = 0 def avg_error(self): return np.absolute(self.b).sum() |