METHOD TO REDUCE LOADS AND VIBRATION IN AIRCRAFT WITH MULTI-BLADE SCREW PROPELLERS WITH EVEN NUMBER OF BLADES Russian patent published in 2010 - IPC B64C11/04 

FIELD: transport.

SUBSTANCE: invention relates to aircraft engineering, particularly, to air screws. Proposed method comprises irregular arrangement of blades, mounted impairs in symmetry about screw orthogonal axes, varying screw types, determining mathematical model of computing harmonic components of variable-load vectors for every blade depending upon angles between axes of adjacent pairs of blades ΔΨ₁. It includes also summation of load vectors from every blade along three axes OY₁, OX₁, OZ₁ of rotary system of coordinates with initial point at screw hub center, projecting obtained vectors onto fixed axes of aircraft coordinates O_fX_f and O_fZ_f, performing harmonic analysis of projection of load vectors onto lengthwise O_fX_f and crosswise O_fZ_f axes and constructing dependencies of amplitudes of said harmonic components upon angles ΔΨ₁ and selection of designed angles corresponding to minimum level of variable load harmonics.

EFFECT: increased life.

2 cl, 7 dwg