Updated and marked up code.

This commit is contained in:
Anne de Jong 2018-12-16 13:08:34 +01:00
parent 51637605b7
commit f0ec52f51f
2 changed files with 104 additions and 101 deletions

115
blflow.py Executable file → Normal file
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@ -1,72 +1,83 @@
#!/usr/bin/python
# Boundary layer flow
from numpy import *
import time
import matplotlib
matplotlib.use('TkAgg')
# from matplotlib.pylab import *
import pylab as p
# import matplotlib.animation as animation
def K(t): #Forcing function
return (1-exp(-0.1*t))*cos(t)
import numpy as np
import matplotlib.pyplot as plt
s=10
#Define domain
n=50 #Number of gridpoints
y=linspace(0,1,n)
def K(t):
"""
Forcing function as a function of time.
"""
return (1-np.exp(-0.1*t))*np.cos(t)
dy=y[1]-y[0]
dt=0.0005
l=(dt/(s**2*dy**2))
s = 10 # Shear wave number
n = 50 # Number of gridpoints in vertical direction
hnu=exp(-sqrt(1j)*s*y)
# Grid
y = np.linspace(0, 1, n)
dy = y[1]-y[0]
dt = 0.0005
l = (dt/(s**2*dy**2))
hnu = np.exp(-np.sqrt(1j)*s*y)
# fnu=(1-1j)/s
fnu=0
fnu = 0
def u_ex(tn):
return (((1-hnu)/(1-fnu))*exp(1j*(tn))/1j).real
"""
Exact harmonic solution of the velocity field
"""
return (((1-hnu)/(1-fnu))*np.exp(1j*(tn))/1j).real
def u_np1(un,tn,dt):
Kn=K(tn)
unp1=un
unp1[0]=0 #Velocity zero ver here
unp1[1:-1]=un[1:-1]+dt*Kn+l*(un[0:-2]-2*un[1:-1]+un[2:])
unp1[-1]=unp1[-2] #Approximate 'infinity' bc
def u_np1(un, tn, dt):
Kn = K(tn)
unp1 = un
unp1[0] = 0 # Velocity zero ver here
unp1[1:-1] = un[1:-1]+dt*Kn+l*(un[0:-2]-2*un[1:-1]+un[2:])
unp1[-1] = unp1[-2] # Approximate 'infinity' bc
return unp1
un0=zeros(n,float)
t=0
un=un0
un0 = np.zeros(n, float)
t = 0
un = un0
# un.append(un0)
# Make the plot
p.ion()
linefd, = p.plot(un0,y)
linee, = p.plot(un0,y)
p.legend(('Finite difference','Periodic exact'))
p.ylim(0,1)
p.xlim(-1.5,1.5)
p.ylabel('y')
p.xlabel('u')
p.grid('on')
i=0
uold=un
while(True):
t+=dt
uold=un
un=u_np1(uold,t,dt)
if(i%100==0):
linefd.set_xdata(un)
linee.set_xdata(u_ex(t))
p.draw()
# print("Time:",t)
i+=1
# plt.ioff()
f = plt.figure(1, figsize=(12, 6))
linefd, = plt.plot(un0, y)
linee, = plt.plot(un0, y)
plt.legend(('Finite difference', 'Periodic exact'))
plt.ylim(0, 1)
plt.xlim(-1.5, 1.5)
plt.ylabel('Distance from wall [m]')
plt.xlabel('Velocity [m/s]')
plt.grid(True)
plt.show(block=False)
i = 0
uold = un
try:
while(True):
t += dt
uold = un
un = u_np1(uold, t, dt)
if(i % 100 == 0):
linefd.set_xdata(un)
linee.set_xdata(u_ex(t))
f.canvas.draw_idle()
plt.pause(.00001)
if not plt.fignum_exists(1):
break
i += 1
except Exception:
pass
exit(0)

86
parplateflow.py Executable file → Normal file
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@ -1,74 +1,66 @@
#!/usr/bin/python
# Boundary layer flow
from numpy import *
import time
import matplotlib
matplotlib.use('TkAgg')
# from matplotlib.pylab import *
import pylab as p
from numpy import zeros, linspace, exp, cos, cosh, sqrt, tanh
import matplotlib.pyplot as plt
# import matplotlib.animation as animation
def K(t): #Forcing function
def K(t): # Forcing function
return (1-exp(-0.1*t))*cos(t)
s=10
#Define domain
n=50 #Number of gridpoints
y=linspace(-1,1,n)
s = 10
dy=y[1]-y[0]
dt=0.0005
# Define domain
n = 50 # Number of gridpoints
y = linspace(-1, 1, n)
l=(dt/(s**2*dy**2))
dy = y[1]-y[0]
dt = 0.0005
hnu=cosh(sqrt(1j)*s*y)/cosh(sqrt(1j)*s)
fnu=tanh(sqrt(1j)*s)/(sqrt(1j)*s)
l = (dt/(s**2*dy**2))
hnu = cosh(sqrt(1j)*s*y)/cosh(sqrt(1j)*s)
fnu = tanh(sqrt(1j)*s)/(sqrt(1j)*s)
def u_ex(tn):
return (((1-hnu)/(1-fnu))*exp(1j*(tn))/1j).real
def u_np1(un,tn,dt):
Kn=K(tn)
unp1=un
unp1[0]=0 #Velocity zero ver here
unp1[1:-1]=un[1:-1]+dt*Kn+l*(un[0:-2]-2*un[1:-1]+un[2:])
unp1[-1]=0 #Boundary other side
def u_np1(un, tn, dt):
Kn = K(tn)
unp1 = un
unp1[0] = 0 # Velocity zero ver here
unp1[1:-1] = un[1:-1]+dt*Kn+l*(un[0:-2]-2*un[1:-1]+un[2:])
unp1[-1] = 0 # Boundary other side
return unp1
un0=zeros(n,float)
t=0
un=un0
un0 = zeros(n, float)
t = 0
un = un0
# un.append(un0)
# Make the plot
p.ion()
linefd, = p.plot(un0,y)
linee, = p.plot(un0,y)
p.legend(('Finite difference','Periodic exact'))
p.ylim(-1,1)
p.xlim(-1.5,1.5)
p.ylabel('y')
p.xlabel('u')
p.grid('on')
i=0
uold=un
linefd, = plt.plot(un0, y)
linee, = plt.plot(un0, y)
plt.legend(('Finite difference', 'Periodic exact'))
plt.ylim(-1, 1)
plt.xlim(-1.5, 1.5)
plt.ylabel('y')
plt.xlabel('u')
plt.grid('on')
i = 0
uold = un
while(True):
t+=dt
uold=un
un=u_np1(uold,t,dt)
if(i%100==0):
t += dt
uold = un
un = u_np1(uold, t, dt)
if(i % 100 == 0):
linefd.set_xdata(un)
linee.set_xdata(u_ex(t))
p.draw()
plt.draw()
# print("Time:",t)
i+=1
i += 1