Add example testing TI in emg

[paulf81]

Add ti-mixing to EMG

(Redoing PR #838 rather than a complicated merge)

This may not be an actual pull request, but may be convenient if it yields some changes. The purpose of this is to look at making a version of EMG with atmospheric_ti_gain re-enabled. To this end I started with a small pseudo-example that compares the power output of columns of a wind farm from the current default EMG to one which uses atmospheric_ti_gain.

I had in mind a step by step criteria, ideally:

• The row averaged power ratios will be similar when 6% TI is used
• The row averaged power ratios will also be similar when IEC-reference TI per wind speed (provided using the Iref function in WindRose), or not, this might need something thinking
• The wakes will be deeper when TI < 6%
• The wakes will be shallower when TI > 6%

Note this is just a start but thought it a convenient way to collaborate. Note also this is very messy until the namespace changes go into v4. The only file worth checking is: examples/xx_add_ti_to_emg.py

Tagging: @misi9170 @jfrederik-nrel

[paulf81]

hi @rafmudaf, this one is sort of scratch for this line of work, is there a way to re-open this unattached to the v4 release?

[rafmudaf]

Ah, I deleted the v4 branch since that has been merged now, and I didn't realize there were still pull requests going to it.

[paulf81]

We should re-target these to develop then right?