[docs]def wc(tdb, v, **kwargs):
"""Calculates the Wind Chill Index (WCI) in accordance with the ASHRAE 2017 Handbook Fundamentals - Chapter 9 [18]_.
The wind chill index (WCI) is an empirical index based on cooling measurements
taken on a cylindrical flask partially filled with water in Antarctica
(Siple and Passel 1945). For a surface temperature of 33°C, the index describes
the rate of heat loss from the cylinder via radiation and convection as a function
of ambient temperature and wind velocity.
This formulation has been met with some valid criticism. WCI is unlikely to be an
accurate measure of heat loss from exposed flesh, which differs from plastic in terms
of curvature, roughness, and radiation exchange qualities, and is always below 33°C
in a cold environment. Furthermore, the equation's values peak at 90 km/h and then
decline as velocity increases. Nonetheless, this score reliably represents the
combined effects of temperature and wind on subjective discomfort for velocities
below 80 km/h [18]_.
Parameters
----------
tdb : float
dry bulb air temperature,[°C]
v : float
wind speed 10m above ground level, [m/s]
Other Parameters
----------------
round: boolean, default True
if True rounds output value, if False it does not round it
Returns
-------
wci: float
wind chill index, [W/m2)]
Examples
--------
.. code-block:: python
>>> from pythermalcomfort.models import wc
>>> wc(tdb=-5, v=5.5)
{"wci": 1255.2}
"""
default_kwargs = {
"round": True,
}
kwargs = {**default_kwargs, **kwargs}
wci = (10.45 + 10 * v**0.5 - v) * (33 - tdb)
# the factor 1.163 is used to convert to W/m2
wci = wci * 1.163
if kwargs["round"]:
wci = round(wci, 1)
return {"wci": wci}