|
WIND MODELING
Wind velocity and direction
strongly influences the convective heat transfer. The RadTherm/RT wind algorithm
calculates the convection coefficient based on wind direction/ speed and accounts for the
heat transfer due to rain. Convection is computed by calculating the direction of
the wind relative to each element and the temperature difference between the air and the
element.
Specific to modeling wind
for the Montana State University project is the use of localized wind conditions. Data
from widely spaced weather stations provides rough estimates for the surface wind at
different road sections.
Special data is NOT required
and most models use weather files. Weather files are ASCII text files that contain
the following information:
| Variable |
Description |
| TIME |
TIME that the
following weather conditions were observed. This is zone time in military style, where
2:30 P.M. is expressed as 1430 hours. Note that midnight should be expressed as 0000 hours
and not 2400 hours. |
| AIRT |
AIR Temperature in C.
|
| SOLAR |
SOLAR irradiance in
W/m2 (total solar on horizontal). |
| WIND |
WIND speed in m/s. |
| HUMID |
HUMIDity in percent
(0 - 100). |
| CLOUD |
CLOUD cover in tenths
(0 = Clear, 10 = Total Overcast). |
| LWIR |
Long Wave
InfraRed radiation in W/m2. |
| WINDIR |
WIND DIRection in
from North to East in degrees (0-359). |
| RAINRATE |
RATE of RAINfall
in mm/hr. (Optional) |
|
