Thanks, all. I've been really tied up at work with no chance for experimentation with more tufts, but I'll get around to it.
I've read through a great many patents, and I know that they will fudge as much as they can to delay copycats. They have to make it at least theoretically workable, so that the actual working device is covered.
This design has the best conceptual basis for making large contrarotating vortices that I've run across so far. It also doesn't need to be oriented at any particularly critical angle to the airflow, so you have some latitude in mounting them.
The Mitsubishi paper (that is available online) specified that the simple delta wedge shaped VG's had to be oriented at 15 degrees to the airstream to work well.
This is fun stuff!
