Making a mesh

[dlorod55]

Hi, i was wondering how to make a mesh for my turtleFSI I edited TF_cfd and removed the flag properties but need to edit the mesh to do the same but don't now how to adjust it .

File under GNU GPL (v3) licence, see LICENSE file for details.

This software is distributed WITHOUT ANY WARRANTY; without even

the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR

PURPOSE.

"""Problem file for running the "CFD" benchmarks in [1]. The problem is a channel flow with a circle and a flag attached to it. For the CFD problem both the circle and flag is rigid.

[1] Turek, Stefan, and Jaroslav Hron. "Proposal for numerical benchmarking of fluid-structure interaction between an elastic object and laminar incompressible flow." Fluid-structure interaction. Springer, Berlin, Heidelberg, 2006. 371-385."""

from dolfin import * import numpy as np from os import path

from turtleFSI.problems import from turtleFSI.modules import

def set_problem_parameters(default_variables, **namespace):

Overwrite or add new variables to 'default_variables'

default_variables.update(dict(
    # Temporal variables
    T=30,                     # End time [s]
    dt=0.01,                  # Time step [s]
    theta=0.5,                # Temporal scheme

    # Physical constants
    rho_f=1.0E3,              # Fluid density [kg/m3]
    mu_f=1.0,                 # Fluid dynamic viscosity [Pa.s]
    Um=2.0,                   # Max. velocity inlet (CDF3: 2.0) [m/s]

    # Problem specific
    folder="TF_cfd_results",  # Name of the results folder
    solid="no_solid",         # Do not solve for the solid
    extrapolation="no_extrapolation",  # No displacement to extrapolate

    # Geometric variables
    H=0.41,                   # Total height
    L=2.5))                   # Length of domain

return default_variables

def get_mesh_domain_and_boundaries(L, H, **namespace):

Load and refine mesh

mesh = Mesh(path.join(path.dirname(path.abspath(__file__)), "..", "mesh", "TF_cfd.xml.gz"))
mesh = refine(mesh)

# Define the boundaries
Inlet = AutoSubDomain(lambda x: near(x[0], 0))
Outlet = AutoSubDomain(lambda x: near(x[0], L))
Walls = AutoSubDomain(lambda x: near(x[1], 0) or near(x[1], H))

# Mark the boundaries
Allboundaries = DomainBoundary()
boundaries = MeshFunction("size_t", mesh, mesh.geometry().dim() - 1)
boundaries set_all(0)
Allboundaries.mark(boundaries, 4)  # Circle and flag
Inlet.mark(boundaries, 1)
Walls.mark(boundaries, 2)
Outlet.mark(boundaries, 3)

# Define the domain
domains = MeshFunction("size_t", mesh, mesh.geometry().dim())
domains.set_all(1)

return mesh, domains, boundaries

def initiate(**namespace):

Lists to hold displacement, forces, and time

drag_list = []
lift_list = []
time_list = []

return dict(drag_list=drag_list, lift_list=lift_list, time_list=time_list)

class Inlet(UserExpression): def init(self, Um, H, *kwargs): self.Um = Um 1.5 self.H = H self.factor = 0 super().init(**kwargs)

def update(self, t):
    if t < 2:
        self.factor = 0.5 * (1 - np.cos(t * np.pi / 2)) * self.Um
    else:
        self.factor = self.Um

def eval(self, value, x):
    value[0] = self.factor * x[1] * (self.H - x[1]) / (self.H / 2.0)**2
    value[1] = 0

def value_shape(self):
    return (2,)

def create_bcs(DVP, Um, H, v_deg, boundaries, **namespace):

Create inlet expression

inlet = Inlet(Um, H, degree=v_deg)

# Fluid velocity conditions
u_inlet = DirichletBC(DVP.sub(1), inlet, boundaries, 1)
u_wall = DirichletBC(DVP.sub(1), ((0.0, 0.0)), boundaries, 2)

# Pressure Conditions
p_out = DirichletBC(DVP.sub(2), 0, boundaries, 3)

return dict(bcs=[u_wall, u_inlet, p_out], inlet=inlet)

def pre_solve(t, inlet, **namespace): """Update boundary conditions""" inlet.update(t)

def postsolve(t, dvp, n, drag_list, lift_list, time_list, mu_f, verbose, ds, **namespace):

Get deformation, velocity, and pressure

d = dvp_["n"].sub(0, deepcopy=True)
v = dvp_["n"].sub(1, deepcopy=True)
p = dvp_["n"].sub(2, deepcopy=True)

# Compute forces
force = dot(sigma(v, p, d, mu_f), n)
drag_list.append(-assemble(force[0]*ds(4)))
lift_list.append(-assemble(force[1]*ds(4)))
time_list.append(t)

# Print results
if MPI.rank(MPI.comm_world) == 0 and verbose:
    print("Drag: {:e}".format(drag_list[-1]))
    print("Lift: {:e}".format(lift_list[-1]))

def finished(drag_list, lift_list, time_list, results_folder, **namespace):

Store results when the computation is finished

if MPI.rank(MPI.comm_world) == 0:
    np.savetxt(path.join(results_folder, 'Lift.txt'), lift_list, delimiter=',')
    np.savetxt(path.join(results_folder, 'Drag.txt'), drag_list, delimiter=',')
    np.savetxt(path.join(results_folder, 'Time.txt'), time_list, delimiter=',')

[keiyamamo]

I have no idea how your mesh is supposed to look like. Also, please format properly.

[keiyamamo]

Closing. Feel free to reopn @dlorod55 .