smoke test at EndX - Brian Lantz, Jim Warner, Siddhesh Pai, Brijesh Pant
Nov 29 2017, about 2:08 pm local
used 1 2B candle from superior signal

burn is ~60 sec.
https://youtu.be/XbouhfAK1Mg

smoke candle is ~10ft in front of the fence,

The smoke candle is about 11 ft. up off the ground, close to the vertical center of the fence material. The picture below shows the pole we used w/ Jim as scale standing next to the fence - The smoke emitter will be placed at the height of the blue tape on the pole.

We took several videos, the one from Brian's phone is linked above.

The smoke trail clear to the fence, but often difficult to see downstream of the fence. Why?
1. partly due to blue sky behind early trail and clouds behind late trail. note this for future film angles
2. trail is darker behind fence - might be some shade?
3. trail is getting bigger.
4. the place where the candle burned though was next to the post.

 - next tests we might try 2 candles together, and try to shoot against blue sky. i'm not sure I have enough candles to use 2 each for all my desired tests.

We see that the smoke moves through the fence. It seems like the fence might be "softening" the edges of the trails my generating lots of short scale mixing, but the structure at the ~1 foot scale seems unaffected by the fence.

Is the air moving more slowly behind the fence? Maybe? I sort of looks this way, but I can't understand how this would be true, if none of the air flow is getting diverted up-and-over or sideways-and-around the fence.
1. It is not going up over the fence -> if you assume the same density, then conservation of mass suggests that the speed on the two sides needs to match.
2. It might be slipping sideways instead of going over - this could allow slower speeds and would not be visible from this camera view -
3. It sort of looks slower - this could be the result of the smoke getting further away from the camera as it moves downwind. how to watch for this at EY?
 - maybe have a camera on the ground at the corner of the building looking up?

4. The structure of the plume moves right though this fence. The fence can't be adding large, immediate changes to the vertical velocity

More videos and pictures will be added, and we are planning to do some additional tests on Friday.

Jim set up an anemometer a bit (something like 50 feet) upwind of the fence to record the wind speed. Data download is pending.