Forking this for personal modifications.

pompy is a NumPy based implementation of the puff-based odour plume model described in Filament-Based Atmospheric Dispersion Model to Achieve Short Time-Scale Structure of Odor Plumes by Farrell et al. (2002).

What is this repository for?

This Python package allows simulation of dynamic 2D odour concentration fields which show some of the key characteristics of real chemical plumes in turbulent flows including short term intermittency, diffusive effects and longer term variations in spatial extent and location, while being significantly cheaper to run than a full fluid dynamics simulation.

Installation and requirements

pompy was developed in Python 2.7. For basic usage of the models the two dependencies are NumPy and SciPy. For the demonstrations Matplotlib is also required. To install in the current Python environment run

python setup.py install

Example usage

See also pompy/demos.py module.

from pompy import models, processors
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation

# Define simulation region
wind_region = models.Rectangle(0., -2., 10., 2.)
sim_region = models.Rectangle(0., -0.5, 2., 0.5)

# Set up wind model
wind_grid_dim_x = 21
wind_grid_dim_y = 11
wind_vel_x_av = 2.
wind_vel_y_av = 0.
wind_model = models.WindModel(
    wind_region, wind_grid_dim_x, wind_grid_dim_y, 
    wind_vel_x_av, wind_vel_y_av)
    
# Set up plume model
source_pos = (0.1, 0., 0.)
centre_rel_diff_scale = 1.5
puff_release_rate = 500
puff_init_rad = 0.001
plume_model = models.PlumeModel(
    sim_region, source_pos, wind_model,
    centre_rel_diff_scale=centre_rel_diff_scale,
    puff_release_rate=puff_release_rate, 
    puff_init_rad=puff_init_rad)

# Create a concentration array generator
array_z = 0.01
array_dim_x = 500
array_dim_y = 500
puff_mol_amount = 1.
array_gen = processors.ConcentrationArrayGenerator(
    sim_region, array_z, array_dim_x, array_dim_y, puff_mol_amount)

# Set up figure
fig = plt.figure(figsize=(6, 3))
ax = fig.add_axes([0., 0., 1., 1.])
ax.axis('off')

# Display initial concentration field as image
conc_array = array_gen.generate_single_array(plume_model.puff_array)
im_extents = (sim_region.x_min, sim_region.x_max,
              sim_region.y_min, sim_region.y_max)
conc_im = ax.imshow(conc_array.T, extent=im_extents, vmin=0., vmax=5e4, cmap='Reds')

# Define animation update function
def update(i):
    dt = 0.005
    wind_model.update(dt)
    plume_model.update(dt)
    conc_array = array_gen.generate_single_array(plume_model.puff_array)
    conc_im.set_data(conc_array.T)
    return [conc_im]

# Animate plume concentration and save as fig
anim = FuncAnimation(fig, update, frames=100, interval=100, repeat=False)
anim.save('plume.gif', dpi=100, writer='imagemagick')