Control system with airfeed
Out of the cited experimental developments, methods were verified for changing lift of profiles injecting air into the grooves.
This development did go a decisive step beyond earlier work done in the early 70‘s summarized with the patent below.
Typical lift-change as a function of injected air, taken from tests at IMHEF Swiss Federal Institute of Technology Lausanne high speed cavitation tunnel runs.
If extended to very high speeds by proper groove dimensions applicability, see Supramar Anti Cavitation Groove