- 157: PROPS, Site NCAR, Fri 24-Jul-1998 12:30:48 CDT, Change 1m. Wind Sensor
Swapped out 1m. wind sensor. 12:30p.m. Old serial number 001, new serial number 002. No more spares. Wobbles in the wind. Looks like bent shaft as well as burnt bearings.
Entered 305 as prop pitch as that is what was in old sensor. We are now using same prop in new sensor.
- 125: PROPS, Site , Wed 15-Jul-1998 17:55:55 CDT, zero wind cases
The winds have been calm for reasonably long periods 2 and 3 nights ago.
These would be good candidates to look at prop/cup stall speeds.
- 96: PROPS, Site NCAR, Tue 07-Jul-1998 16:28:24 CDT, flipped 6.5m prop vane
Since flipping the 2m vane worked so well, I've just flipped the 6.5m prop
also.
- 90: PROPS, Site NCAR, Tue 07-Jul-1998 09:13:17 CDT, flipped vane on 2m
I just flipped the vane on the 2m prop (the RM Young lettering is now
upside down) to test if the 2 degree difference in wind direction is due
to some asymmetry in the vane. I could imagine that the vane was slightly
bent (I off to the left, when viewed upside down from the hub).
We'll look at today's data to see if there was an effect. Tom points out
that the 1m could be bent instead, so we can try it tomorrow.
- 63: PROPS, Site OKMN, Tue 30-Jun-1998 14:55:24 CDT, Straightened 2 m cup anemometer
17:30 UTC: Straightened 2 m cup anemometer
- 58: PROPS, Site OKMN, Tue 30-Jun-1998 11:28:56 CDT, OKMN 2m cups are tilted to south
The cup anemometer at 2m on the mesonet tower is tilted a few
degrees to the south.
- 48: PROPS, Site , Sun 28-Jun-1998 12:00:36 CDT, New Prop angles
I shot the props again today. Below are the results.
There is not much difference from the first time except
for the 2m prop which we moved. The new angle for the
2m prop was entered into the eeprom at ~11:50 local.
The 6.5m prop has a slight tilt. I believe this is
due to the mounting of the yoke to the tower.
We may try to change it.
Prop angle
1m 177 42' 35"
2m 178 13' 10"
4.5m 176 55' 53"
6.5m 176 27' 35"
9m 178 55' 40"
- 45: PROPS, Site , Sat 27-Jun-1998 12:01:52 CDT, Prop direction differences
There is a difference in the ASTER prop directions.
When looking at data over a long time period with 1 hour
averaging, the 2m and 6.5m are about 2 degrees off compared
to the 1m. While the 4.5m and 9m are about a degree off.
The boom alignment was checked on the 1m and 2m. There was
no changed when the vanes were re-aligned. The error may be
due to the direction angle measurements. When shooting the
angles, the 1m and 2m where shot without moving the tripod.
The same conditions were used on the 4.5m and the 6.5m.
We will try shooting the angles again in the next few days
to see if this answers the question.
- 20: PROPS, Site , Sun 21-Jun-1998 11:52:09 CDT, Prop boom azimuths
Steve shot the azimuths of the prop booms, using the theodolite
and the sun angle program.
1m 357d 42m 02s 177.7
2m 357d 41m 50s 177.7
4.5m 356d 53m 25s 176.9
6.5m 356d 20m 50s 176.3
9m 358d 45m 30s 178.8
At 15:15 CDT entered boom azimuth coefficients into props as listed
in the second column above
- 11: PROPS, Site , Fri 19-Jun-1998 10:26:47 CDT, Entered prop pitches
Steve entered prop pitches:
9m 304
6.5m 304
4.5m 305
2m 305
1m 305