J. Kissel for the Wind Team

I took the opportunity to grab some pictures of the X-End building exterior and brand new wind fence pathfinder. Winds were roughly 25 mph, so I also grabbed a video. It's too big for the aLOG, so I've posted it to youtube.

Notes on the fence:
- There we no tumbleweeds gathered around the fence
- The material seems to be holding up well (not stressed/stretched too much where it's attached to the fence), and 
- pressing on the back of the material opposite the wind direction it feels like a fully extended sail, but not near any yield point.
- The tops of the posts are rattle a little bit.

The final, as built, design of the fence:
- 3 posts, 24 ft as-purchased; 20 ft is above ground and 4 ft are in concrete in the ground.
- Posts cover 30ft left-to-right, spaced 15 ft apart.
- 6 ft gap between ground and fence material, and material spans the posts left-to-right and is 6 ft tall (so there's room to extend the material upward).
- The material is 30% coverage, or 70% porous. 

Also, 
SEI aLOG 1024 shows the first bit of wind modeling that's being done at Stanford by a summer undergrad Ian Gomez. If you're really cool, you can check out more preliminary results (at this point, just pretty pictures) in the Stanford Engineering Test Facility's eLogBook: ETF eLOG 2593.

My thoughts, after seeing these initial results -- which (rightfully so) start off with a flat bit of ground and a simple box for a building -- that those simple models will get us pretty far for the Y-end where the topography is pretty darn flat. However, the topography is more interesting at the X-end, and my hope would be that by the end of the summer, Ian's models might get just sophisticated enough to predict wind flow around the X-end building. 

You'll recall from the single-PEM-anemometer comparison between X-end and Y-end during wind storms (see LHO aLOG 17574), that Y-end moves about a factor of 2 more than X-end. The topography may have a good bit to do with it.