BMatthews

Turbulators and turbulator spars are sort of the same and sort of different. True turbulators are strips, saw teeth or other outside surface mountedelementswith their sole purpose being to generate a controlled amount of turbulence. On the other hand turbulator spars are used more for structure and covering support to try to generate a more accurate airfoil profile and perhaps to aid to some extent in generating a tubulent boundry layer.

the supportive stripsin thewing structure thatwe call turbulator spars are typically sanded down flush with the wing surface. And in truth they are primarily support for the covering to try to avoid some of the typical mid rib sag. But at the same time these spars produce a bit of a ridge that can also aid in generating some turbulence. If you use enough close spaced turbulator spars your airfoil becomes primarily a series of flat facets or tangents that form the airfoil since the spars themselves have more effect on supporting the covering than the ribs do. In such a case making the spars high enough to sit slightly above the wing is an option but it's not normally done that way by most builders nor is it shown that way on the big majority ofplans.