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SWIFT
SWIFTsim
Commits
226ff24a
Commit
226ff24a
authored
Jan 13, 2017
by
Matthieu Schaller
Browse files
Also updated the Minimal hydro scheme to the new cooling way
parent
ef8184b8
Changes
3
Hide whitespace changes
Inline
Side-by-side
examples/CoolingBox/test_energy_conservation.py
deleted
100644 → 0
View file @
ef8184b8
import
numpy
as
np
import
matplotlib.pyplot
as
plt
import
h5py
as
h5
import
sys
stats_filename
=
"./energy.txt"
snap_filename
=
"coolingBox_000.hdf5"
#plot_dir = "./"
n_snaps
=
41
time_end
=
4.0
dt_snap
=
0.1
#some constants in cgs units
k_b
=
1.38E-16
#boltzmann
m_p
=
1.67e-24
#proton mass
#initial conditions set in makeIC.py
rho
=
4.8e3
P
=
4.5e6
#n_H_cgs = 0.0001
gamma
=
5.
/
3.
T_init
=
1.0e5
#find the sound speed
#Read the units parameters from the snapshot
f
=
h5
.
File
(
snap_filename
,
'r'
)
units
=
f
[
"InternalCodeUnits"
]
unit_mass
=
units
.
attrs
[
"Unit mass in cgs (U_M)"
]
unit_length
=
units
.
attrs
[
"Unit length in cgs (U_L)"
]
unit_time
=
units
.
attrs
[
"Unit time in cgs (U_t)"
]
parameters
=
f
[
"Parameters"
]
cooling_lambda
=
float
(
parameters
.
attrs
[
"LambdaCooling:lambda_cgs"
])
min_T
=
float
(
parameters
.
attrs
[
"LambdaCooling:minimum_temperature"
])
mu
=
float
(
parameters
.
attrs
[
"LambdaCooling:mean_molecular_weight"
])
X_H
=
float
(
parameters
.
attrs
[
"LambdaCooling:hydrogen_mass_abundance"
])
#get number of particles
header
=
f
[
"Header"
]
n_particles
=
header
.
attrs
[
"NumPart_ThisFile"
][
0
]
#read energy and time arrays
array
=
np
.
genfromtxt
(
stats_filename
,
skip_header
=
1
)
time
=
array
[:,
0
]
total_energy
=
array
[:,
2
]
total_mass
=
array
[:,
1
]
time
=
time
[
1
:]
total_energy
=
total_energy
[
1
:]
total_mass
=
total_mass
[
1
:]
#conversions to cgs
rho_cgs
=
rho
*
unit_mass
/
(
unit_length
)
**
3
time_cgs
=
time
*
unit_time
u_init_cgs
=
total_energy
[
0
]
/
(
total_mass
[
0
])
*
unit_length
**
2
/
(
unit_time
)
**
2
n_H_cgs
=
X_H
*
rho_cgs
/
m_p
#find the sound speed in cgs
c_s
=
np
.
sqrt
((
gamma
-
1.
)
*
k_b
*
T_init
/
(
mu
*
m_p
))
#assume box size is unit length
sound_crossing_time
=
unit_length
/
c_s
print
"Sound speed = %g cm/s"
%
c_s
print
"Sound crossing time = %g s"
%
sound_crossing_time
#find the energy floor
u_floor_cgs
=
k_b
*
min_T
/
(
mu
*
m_p
*
(
gamma
-
1.
))
#find analytic solution
analytic_time_cgs
=
np
.
linspace
(
time_cgs
[
0
],
time_cgs
[
-
1
],
1000
)
du_dt_cgs
=
-
cooling_lambda
*
n_H_cgs
**
2
/
rho_cgs
u_analytic
=
du_dt_cgs
*
(
analytic_time_cgs
-
analytic_time_cgs
[
0
])
+
u_init_cgs
cooling_time
=
u_init_cgs
/
(
-
du_dt_cgs
)
#put time in units of sound crossing time
time
=
time_cgs
/
sound_crossing_time
analytic_time
=
analytic_time_cgs
/
sound_crossing_time
#rescale energy to initial energy
total_energy
/=
total_energy
[
0
]
u_analytic
/=
u_init_cgs
u_floor_cgs
/=
u_init_cgs
# plot_title = r"$\Lambda \, = \, %1.1g \mathrm{erg}\mathrm{cm^3}\mathrm{s^{-1}} \, \, T_{init} = %1.1g\mathrm{K} \, \, T_{floor} = %1.1g\mathrm{K} \, \, n_H = %1.1g\mathrm{cm^{-3}}$" %(cooling_lambda,T_init,T_floor,n_H)
# plot_filename = "energy_plot_creasey_no_cooling_T_init_1p0e5_n_H_0p1.png"
#analytic_solution = np.zeros(n_snaps-1)
for
i
in
range
(
u_analytic
.
size
):
if
u_analytic
[
i
]
<
u_floor_cgs
:
u_analytic
[
i
]
=
u_floor_cgs
plt
.
plot
(
time
-
time
[
0
],
total_energy
,
'k'
,
label
=
"Numerical solution from energy.txt"
)
plt
.
plot
(
analytic_time
-
analytic_time
[
0
],
u_analytic
,
'r'
,
lw
=
2.0
,
label
=
"Analytic Solution"
)
#now get energies from the snapshots
snapshot_time
=
np
.
linspace
(
0
,
time_end
,
num
=
n_snaps
)
snapshot_time
=
snapshot_time
[
1
:]
snapshot_time_cgs
=
snapshot_time
*
unit_time
snapshot_time
=
snapshot_time_cgs
/
sound_crossing_time
snapshot_time
-=
snapshot_time
[
0
]
snapshot_energy
=
np
.
zeros
(
n_snaps
)
for
i
in
range
(
0
,
n_snaps
):
snap_filename
=
"coolingBox_%03d.hdf5"
%
i
f
=
h5
.
File
(
snap_filename
,
'r'
)
snapshot_internal_energy_array
=
np
.
array
(
f
[
"PartType0/InternalEnergy"
])
total_internal_energy
=
np
.
sum
(
snapshot_internal_energy_array
)
velocity_array
=
np
.
array
(
f
[
"PartType0/Velocities"
])
total_kinetic_energy
=
0.5
*
np
.
sum
(
velocity_array
**
2
)
snapshot_energy
[
i
]
=
total_internal_energy
+
total_kinetic_energy
snapshot_energy
/=
snapshot_energy
[
0
]
snapshot_energy
=
snapshot_energy
[
1
:]
plt
.
plot
(
snapshot_time
,
snapshot_energy
,
'bd'
,
label
=
"Numerical solution from snapshots"
)
#plt.title(r"$n_H = %1.1e \, \mathrm{cm}^{-3}$" %n_H_cgs)
plt
.
xlabel
(
"Time (sound crossing time)"
)
plt
.
ylabel
(
"Energy/Initial energy"
)
plt
.
ylim
(
0.99
,
1.01
)
#plt.xlim(0,min(10,time[-1]))
plt
.
legend
(
loc
=
"upper right"
)
if
(
int
(
sys
.
argv
[
1
])
==
0
):
plt
.
show
()
else
:
plt
.
savefig
(
full_plot_filename
,
format
=
"png"
)
plt
.
close
()
src/hydro/Minimal/hydro.h
View file @
226ff24a
...
...
@@ -49,26 +49,22 @@
* energy from the thermodynamic variable.
*
* @param p The particle of interest
* @param dt Time since the last kick
*/
__attribute__
((
always_inline
))
INLINE
static
float
hydro_get_internal_energy
(
const
struct
part
*
restrict
p
,
float
dt
)
{
const
struct
part
*
restrict
p
)
{
return
p
->
u
+
p
->
u_dt
*
dt
;
return
p
->
u
;
}
/**
* @brief Returns the pressure of a particle
*
* @param p The particle of interest
* @param dt Time since the last kick
*/
__attribute__
((
always_inline
))
INLINE
static
float
hydro_get_pressure
(
const
struct
part
*
restrict
p
,
float
dt
)
{
const
float
u
=
p
->
u
+
p
->
u_dt
*
dt
;
const
struct
part
*
restrict
p
)
{
return
gas_pressure_from_internal_energy
(
p
->
rho
,
u
);
return
gas_pressure_from_internal_energy
(
p
->
rho
,
p
->
u
);
}
/**
...
...
@@ -79,24 +75,20 @@ __attribute__((always_inline)) INLINE static float hydro_get_pressure(
* the thermodynamic variable.
*
* @param p The particle of interest
* @param dt Time since the last kick
*/
__attribute__
((
always_inline
))
INLINE
static
float
hydro_get_entropy
(
const
struct
part
*
restrict
p
,
float
dt
)
{
const
float
u
=
p
->
u
+
p
->
u_dt
*
dt
;
const
struct
part
*
restrict
p
)
{
return
gas_entropy_from_internal_energy
(
p
->
rho
,
u
);
return
gas_entropy_from_internal_energy
(
p
->
rho
,
p
->
u
);
}
/**
* @brief Returns the sound speed of a particle
*
* @param p The particle of interest
* @param dt Time since the last kick
*/
__attribute__
((
always_inline
))
INLINE
static
float
hydro_get_soundspeed
(
const
struct
part
*
restrict
p
,
float
dt
)
{
const
struct
part
*
restrict
p
)
{
return
p
->
force
.
soundspeed
;
}
...
...
@@ -124,68 +116,31 @@ __attribute__((always_inline)) INLINE static float hydro_get_mass(
}
/**
* @brief Modifies the thermal state of a particle to the imposed internal
* energy
* @brief Returns the time derivative of internal energy of a particle
*
* This overwrites the current state of the particle but does *not* change its
* time-derivatives. Internal energy, pressure, sound-speed and signal velocity
* will be updated.
* We assume a constant density.
*
* @param p The particle
* @param u The new internal energy
* @param p The particle of interest
*/
__attribute__
((
always_inline
))
INLINE
static
void
hydro_set_internal_energy
(
struct
part
*
restrict
p
,
float
u
)
{
p
->
u
=
u
;
/* Compute the new pressure */
const
float
pressure
=
gas_pressure_from_internal_energy
(
p
->
rho
,
p
->
u
);
/* Compute the new sound speed */
const
float
soundspeed
=
gas_soundspeed_from_internal_energy
(
p
->
rho
,
p
->
u
);
/* Update the signal velocity */
const
float
v_sig_old
=
p
->
force
.
v_sig
;
const
float
v_sig_new
=
p
->
force
.
v_sig
-
p
->
force
.
soundspeed
+
soundspeed
;
const
float
v_sig
=
max
(
v_sig_old
,
v_sig_new
);
__attribute__
((
always_inline
))
INLINE
static
float
hydro_get_internal_energy_dt
(
const
struct
part
*
restrict
p
)
{
p
->
force
.
soundspeed
=
soundspeed
;
p
->
force
.
pressure
=
pressure
;
p
->
force
.
v_sig
=
v_sig
;
return
p
->
u_dt
;
}
/**
* @brief
Modifies the thermal state of a particle to the imposed entropy
* @brief
Returns the time derivative of internal energy of a particle
*
* This overwrites the current state of the particle but does *not* change its
* time-derivatives. Internal energy, pressure, sound-speed and signal velocity
* will be updated.
* We assume a constant density.
*
* @param p The particle
* @param
S
The new
entropy
* @param p The particle
of interest.
* @param
du_dt
The new
time derivative of the internal energy.
*/
__attribute__
((
always_inline
))
INLINE
static
void
hydro_set_entropy
(
struct
part
*
restrict
p
,
float
S
)
{
p
->
u
=
gas_internal_energy_from_entropy
(
p
->
rho
,
S
);
__attribute__
((
always_inline
))
INLINE
static
void
hydro_set_internal_energy_dt
(
struct
part
*
restrict
p
,
float
du_dt
)
{
/* Compute the pressure */
const
float
pressure
=
gas_pressure_from_internal_energy
(
p
->
rho
,
p
->
u
);
/* Compute the new sound speed */
const
float
soundspeed
=
gas_soundspeed_from_internal_energy
(
p
->
rho
,
p
->
u
);
/* Update the signal velocity */
const
float
v_sig_old
=
p
->
force
.
v_sig
;
const
float
v_sig_new
=
p
->
force
.
v_sig
-
p
->
force
.
soundspeed
+
soundspeed
;
const
float
v_sig
=
max
(
v_sig_old
,
v_sig_new
);
p
->
force
.
soundspeed
=
soundspeed
;
p
->
force
.
pressure
=
pressure
;
p
->
force
.
v_sig
=
v_sig
;
p
->
u_dt
=
du_dt
;
}
/**
* @brief Computes the hydro time-step of a given particle
*
...
...
@@ -406,10 +361,7 @@ __attribute__((always_inline)) INLINE static void hydro_kick_extra(
/* Do not decrease the energy by more than a factor of 2*/
const
float
u_change
=
p
->
u_dt
*
dt
;
if
(
u_change
>
-
0
.
5
f
*
xp
->
u_full
)
xp
->
u_full
+=
u_change
;
else
xp
->
u_full
*=
0
.
5
f
;
xp
->
u_full
=
max
(
xp
->
u_full
+
u_change
,
0
.
5
f
*
xp
->
u_full
);
/* Compute the pressure */
const
float
pressure
=
gas_pressure_from_internal_energy
(
p
->
rho
,
xp
->
u_full
);
...
...
src/hydro/Minimal/hydro_io.h
View file @
226ff24a
...
...
@@ -71,12 +71,12 @@ void hydro_read_particles(struct part* parts, struct io_props* list,
float
convert_S
(
struct
engine
*
e
,
struct
part
*
p
)
{
return
hydro_get_entropy
(
p
,
0
);
return
hydro_get_entropy
(
p
);
}
float
convert_P
(
struct
engine
*
e
,
struct
part
*
p
)
{
return
hydro_get_pressure
(
p
,
0
);
return
hydro_get_pressure
(
p
);
}
/**
...
...
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