A PARAMETRIC DESIGN STUDY FOR ACTIVELY CONTROLLED TRAILING-EDGE FLAPS

A parametric design study is conducted for a plain trailing edge nap s ystem for a typical helicopter. The results show that plain flaps prov ide an effective means of implementing multicyclic control, Significan t reductions in fixed system 4/rev hub loads are predicted. The flap m otions may be optimized for reductions in either hub shears or hub mom ents by varying a scalar weighting parameter in the control algorithm. The effects of variations In flap length, spanwise location, chord, a nd aerodynamic effectiveness could be largely offset by compensating a djustments to the flap commands as determined by the multicyclic algor ithm. Required trailing edge flap power is minimized by reducing the f lap chord to the smallest practical value.