Inheritance diagram for uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence:
Public Member Functions | |
| def | __init__ (self, turbulent_diffusion_coefficients, buoyancy_flux, stability_param, source_pos, n_points, start_time, max_particles_per_iter=10, max_life_time=-1) |
| def | compute_plume_rise (self, t) |
| def | create_particles (self, t) |
| def | max_particles_per_iter (self) |
| def | set_max_particles_per_iter (self, n_particles) |
| def | set_plume_particles (self, t, x, y, z, time_creation) |
| def | update (self, t=0.0) |
Static Public Attributes | |
| string | LABEL = 'passive_scalar_turbulence' |
Private Attributes | |
| _buoyancy_flux | |
| _dt | |
| _max_life_time | |
| _max_particles_per_iter | |
| _pnts | |
| _stability_param | |
| _t | |
| _time_creation | |
| _turbulent_diffusion_coefficients | |
| _vel_turbulent_diffusion | |
Detailed Description
Plume model implementation based on [1]. The chemical plume is described
here by discretized particles generated that are generated on the Cartesian
position given as the source of the plume. The plume is treated as a
passive scalar turbulence, meaning that it will not affect the
environmental fluid flow.
To model the dynamics of the plume particles, the Lagrangian particle
random walk approach [2] is used. The particles are generated from the
source position in batches at each iteration to ensure a steady flow and
each particle has its position $(x_k, y_k, z_k)$ at the instant
$t_k$ computed as
$$
x_k = x_{k - 1} + (u_a + u_i) \Delta t
$$
$$
y_k = y_{k - 1} + (v_a + v_i) \Delta t
$$
$$
z_k = z_{k - 1} + (w_a + w_b + w_i) \Delta t
$$
where $(u_a, v_a, w_a)$ are the particle's velocities due to the
current velocity, $(u_t, v_t, w_t)$ are the particle's velocities
due to turbulent diffusion, and $w_b$ is the vertical buoyant
velocity.
!!! note "[1] `Tian and Zhang, 2010`"
Yu Tian and Aiqun Zhang, "Simulation environment and guidance system
for AUV tracing chemical plume in 3-dimensions," 2010 2nd International
Asia Conference on Informatics in Control, Automation and Robotics
(CAR 2010), Mar. 2010.
!!! note "[2] `Mestres et al., 2003`"
M. Mestres et al., "Modelling of the Ebro River plume. Validation with
field observations," Scientia Marina, vol. 67, no. 4, pp. 379-391,
Dec. 2003.
Definition at line 21 of file passive_scalar_turbulence.py.
Constructor & Destructor Documentation
| def uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence.__init__ | ( | self, | |
| turbulent_diffusion_coefficients, | |||
| buoyancy_flux, | |||
| stability_param, | |||
| source_pos, | |||
| n_points, | |||
| start_time, | |||
max_particles_per_iter = 10, |
|||
max_life_time = -1 |
|||
| ) |
Passive scalar turbulent plume model constructor. > **Parameters** * `turbulent_diffusion_coefficients` (*type:* `list`): a vector with three elements containing the turbulent diffusion coefficients for each degree of freedom of the particles ($x$, $y$ and $z$) * `buoyancy_flux` (*type:* `float`): parameter used to compute the plume rise * `stability_param` (*type:* `float`): parameter used to compute the plume rise * `source_pos` (*type:* `list`): vector containing the Cartesian coordinates for the plume source (represented in the ENU inertial frame) * `n_points` (*type:* `int`): maximum number of particles to be generated for the plume * `start_time` (*type:* `float`): plume model creation time stamp * `max_particles_per_iter` (*default:* 10, *type:* `int`): maximum number of particles to be generated per iteration * `max_life_time` (*type:* `float`): maximum life time for each particle from the time of creation in seconds
Definition at line 67 of file passive_scalar_turbulence.py.
Member Function Documentation
| def uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence.compute_plume_rise | ( | self, | |
| t | |||
| ) |
The plume rise equation is used to compute the vertical buoyant
velocity. It is based on the experimental results presented in [1]
and can be written as
$H(u, s, t) = 2.6 ( F t^2 / u )^{1/3} (t^2 s + 4.3)^{-1/3}$
where $F$ is the buoyancy flux parameter and $s$ the
stability parameters, and both can be tuned by the user. $u$ is
the magnitude of the current velocity on the horizontal plane. The
resulting vertical buoyant velocity will be computed as follows
$w_b = H(u, s, t + \Delta t) - H(u, s, t) / \Delta t$
!!! note "[1] `Domenico, 1985`"
Anfossi, Domenico. "Analysis of plume rise data from five TVA steam
plants." Journal of climate and applied meteorology 24.11 (1985):
1225-1236.
> **Parameters**
* `t` (*type:* `float`): current time stamp in seconds
> **Returns**
Plume rise velocity components vector.
Definition at line 214 of file passive_scalar_turbulence.py.
| def uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence.create_particles | ( | self, | |
| t | |||
| ) |
Create random number of particles for one iteration up to the given maximum limit and remove all particles that have left the plume's bounding box limits. > **Parameters** * `t` (*type:* `float`): time stamp in seconds
Definition at line 140 of file passive_scalar_turbulence.py.
| def uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence.max_particles_per_iter | ( | self | ) |
Return the maximum number of particles to be generated per iteration from the source of the plume.
Definition at line 112 of file passive_scalar_turbulence.py.
| def uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence.set_max_particles_per_iter | ( | self, | |
| n_particles | |||
| ) |
Set the maximum number of particles to be generated per iteration from the source of the plume. > **Parameters** * `n_particles` (*type:* `int`): number of particles > **Returns** `True` if the new maximum number of particles could be set. `False` if the input is equal or smaller than zero.
Definition at line 119 of file passive_scalar_turbulence.py.
| def uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence.set_plume_particles | ( | self, | |
| t, | |||
| x, | |||
| y, | |||
| z, | |||
| time_creation | |||
| ) |
Load the plume particles' position vectors and time of creation.
> **Parameters**
* `t` (*type:* `float`): Current time stamp in seconds
* `x` (*type:* `list`): List of X coordinates
* `y` (*type:* `list`): List of Y coordinates
* `z` (*type:* `list`): List of Z coordinates
* `time_creation` (*type:* `list`): List of time stamps of creation
of each particle
Definition at line 188 of file passive_scalar_turbulence.py.
| def uuv_plume_model.passive_scalar_turbulence.PlumePassiveScalarTurbulence.update | ( | self, | |
t = 0.0 |
|||
| ) |
Update the position of all particles and create/remove particles from the plume according to the bounding box limit constraints and the maximum number of particles allowed. > **Parameters** * `t` (*type:* `float`): current time stamp in seconds > **Returns** `True` if update was succesful, `False` if computed time step is invalid.
Definition at line 251 of file passive_scalar_turbulence.py.
Member Data Documentation
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Definition at line 107 of file passive_scalar_turbulence.py.
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Definition at line 265 of file passive_scalar_turbulence.py.
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Definition at line 103 of file passive_scalar_turbulence.py.
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Definition at line 102 of file passive_scalar_turbulence.py.
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Definition at line 100 of file passive_scalar_turbulence.py.
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Definition at line 109 of file passive_scalar_turbulence.py.
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Definition at line 266 of file passive_scalar_turbulence.py.
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Definition at line 163 of file passive_scalar_turbulence.py.
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Definition at line 98 of file passive_scalar_turbulence.py.
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Definition at line 101 of file passive_scalar_turbulence.py.
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Definition at line 63 of file passive_scalar_turbulence.py.
The documentation for this class was generated from the following file: