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"""Demonstrate the windtunnel simulation using inlet and outlet feature in 2D
inlet fluid outlet
--------- -------- --------
| * * * x | | | | |
u | * * * x | | | | |
---> | * * * x | | airfoil| | |
| * * * x | | | | |
-------- -------- --------
In the figure above, the 'x' are the initial inlet particles. The '*' are the
copies of these. The particles are moving to the right and as they do, new
fluid particles are added and as the fluid particles flow into the outlet they
are converted to the outlet particle array and at last as the particles leave
the outlet they are removed from the simulation. The `create_particles` and
`create_inlet_outlet` functions may also be passed to the `app.setup` method
if needed.
This example can be run in parallel.
"""
import numpy as np
from pysph.base.kernels import CubicSpline
from pysph.base.utils import get_particle_array_wcsph
from pysph.solver.application import Application
from pysph.solver.solver import Solver
from pysph.sph.integrator import PECIntegrator
from pysph.sph.simple_inlet_outlet import SimpleInlet, SimpleOutlet
from pysph.sph.integrator_step import InletOutletStep, TransportVelocityStep
from pysph.sph.integrator_step import InletOutletStep, WCSPHStep
from pysph.sph.scheme import TVFScheme
from pysph.sph.scheme import WCSPHScheme
from pysph.tools.geometry import get_2d_wall, get_2d_block
from pysph.tools.geometry import get_5digit_naca_airfoil
from pysph.tools.geometry import get_4digit_naca_airfoil
from pysph.tools.geometry import remove_overlap_particles
def windtunnel_airfoil_model(dx_wall=0.01, dx_airfoil=0.01, dx_fluid=0.01,
r_solid=100.0, r_fluid=100.0, airfoil='2412',
hdx=1.1, chord=1.0, h_tunnel=1.0, l_tunnel=10.0):
"""
Generates a geometry which can be used for wind tunnel like simulations.
Parameters
----------
dx_wall : a number which is the dx of the wind tunnel wall
dx_airfoil : a number which is the dx of the airfoil used
dx_fluid : a number which is the dx of the fluid used
r_solid : a number which is the initial density of the solid particles
r_fluid : a number which is the initial density of the fluid particles
airfoil : 4 or 5 digit string which is the airfoil name
hdx : a number which is the hdx for the particle arrays
chord : a number which is the chord of the airfoil
h_tunnel : a number which is the height of the wind tunnel
l_tunnel : a number which is the length of the wind tunnel
Returns
-------
wall : pysph wcsph particle array for the wind tunnel walls
wing : pysph wcsph particle array for the airfoil
fluid : pysph wcsph particle array for the fluid
"""
wall_center_1 = np.array([0.0, h_tunnel / 2.])
wall_center_2 = np.array([0.0, -h_tunnel / 2.])
x_wall_1, y_wall_1 = get_2d_wall(dx_wall, wall_center_1, l_tunnel)
x_wall_2, y_wall_2 = get_2d_wall(dx_wall, wall_center_2, l_tunnel)
x_wall = np.concatenate([x_wall_1, x_wall_2])
y_wall = np.concatenate([y_wall_1, y_wall_2])
y_wall_1 = y_wall_1 + dx_wall
y_wall_2 = y_wall_2 - dx_wall
y_wall = np.concatenate([y_wall, y_wall_1, y_wall_2])
y_wall_1 = y_wall_1 + dx_wall
y_wall_2 = y_wall_2 - dx_wall
y_wall = np.concatenate([y_wall, y_wall_1, y_wall_2])
y_wall_1 = y_wall_1 + dx_wall
y_wall_2 = y_wall_2 - dx_wall
x_wall = np.concatenate([x_wall, x_wall, x_wall, x_wall])
y_wall = np.concatenate([y_wall, y_wall_1, y_wall_2])
h_wall = np.ones_like(x_wall) * dx_wall * hdx
rho_wall = np.ones_like(x_wall) * r_solid
mass_wall = rho_wall * dx_wall * dx_wall
wall = get_particle_array_wcsph(name='wall', x=x_wall, y=y_wall, h=h_wall,
rho=rho_wall, m=mass_wall)
if len(airfoil) == 4:
x_airfoil, y_airfoil = get_4digit_naca_airfoil(
dx_airfoil, airfoil, chord)
else:
x_airfoil, y_airfoil = get_5digit_naca_airfoil(
dx_airfoil, airfoil, chord)
x_airfoil = x_airfoil - 0.5
h_airfoil = np.ones_like(x_airfoil) * dx_airfoil * hdx
rho_airfoil = np.ones_like(x_airfoil) * r_solid
mass_airfoil = rho_airfoil * dx_airfoil * dx_airfoil
wing = get_particle_array_wcsph(name='wing', x=x_airfoil, y=y_airfoil,
h=h_airfoil, rho=rho_airfoil,
m=mass_airfoil)
x_fluid, y_fluid = get_2d_block(dx_fluid, 1.6, h_tunnel)
h_fluid = np.ones_like(x_fluid) * dx_fluid * hdx
rho_fluid = np.ones_like(x_fluid) * r_fluid
mass_fluid = rho_fluid * dx_fluid * dx_fluid
fluid = get_particle_array_wcsph(name='fluid', x=x_fluid, y=y_fluid,
h=h_fluid, rho=rho_fluid, m=mass_fluid)
remove_overlap_particles(fluid, wall, dx_wall, 2)
remove_overlap_particles(fluid, wing, dx_airfoil, 2)
return wall, wing, fluid
class WindTunnel(Application):
def add_user_options(self, group):
group.add_argument("--speed", action="store",
type=float,
dest="speed",
default=1.0,
help="Speed of inlet particles.")
def create_particles(self):
dx_airfoil = 0.002
dx_wall = 0.002
wall, wing, fluid = windtunnel_airfoil_model(
dx_wall=dx_wall, dx_airfoil=dx_airfoil)
outlet = get_particle_array_wcsph(name='outlet')
dx = 0.01
y = np.linspace(-0.49, 0.49, 99)
x = np.zeros_like(y) - 0.81
rho = np.ones_like(x) * 100.0
m = rho * dx * dx
h = np.ones_like(x) * dx * 1.1
u = np.ones_like(x) * self.options.speed
inlet = get_particle_array_wcsph(name='inlet', x=x, y=y, m=m, h=h,
u=u, rho=rho)
return [inlet, fluid, wing, outlet, wall]
def create_inlet_outlet(self, particle_arrays):
fluid_pa = particle_arrays['fluid']
inlet_pa = particle_arrays['inlet']
outlet_pa = particle_arrays['outlet']
inlet = SimpleInlet(
inlet_pa, fluid_pa, spacing=0.01, n=19, axis='x', xmin=-1.00,
xmax=-0.81, ymin=-0.49, ymax=0.49
)
outlet = SimpleOutlet(
outlet_pa, fluid_pa, xmin=3.0, xmax=4.0, ymin=-0.5, ymax=0.5
)
return [inlet, outlet]
def create_scheme(self):
s = WCSPHScheme(['fluid', 'inlet', 'outlet'], ['wing', 'wall'],
dim=2, rho0=100.0, c0=10.0, h0=0.011, hdx=1.1,
hg_correction=True)
return s
def create_solver(self):
kernel = CubicSpline(dim=2)
integrator = PECIntegrator(
fluid=WCSPHStep(), inlet=InletOutletStep(),
outlet=InletOutletStep()
)
dt = 0.00005
tf = 20.0
solver = Solver(
kernel=kernel, dim=2, integrator=integrator, dt=dt, tf=tf,
adaptive_timestep=False, pfreq=20
)
return solver
if __name__ == '__main__':
app = WindTunnel()
app.run()
|
