METHOD TO REDUCE NOISE EMISSION IN GAS TURBINE REAR PART AND PERFECTED GAS TURBINE ENGINE Russian patent published in 2010 - IPC F02K1/82 F02K3/06 

FIELD: engines and pumps.

SUBSTANCE: proposed method consists in determining fan channel critical zone starting in nozzle neck and passing forward. Note that in this zone no variations in said channel geometry and, hence, inner tubular surface of acoustic attenuation coat rear part are possible without changing parametres of the nozzle. Note also that aforesaid coat is applied on fan outer fairing inner part. Inner tubular surface in acoustic attenuation coat front part convergent zone is varied in direction of gradual increase in thickness of aforesaid coat to wards aforesaid rear part of this coat. Gradual variation in thickness of the coat rear part inner tubular surface is continued till formation of greater thickness zone in said coat rear part. Greater thickness zone rear end is jointed to critical zone front end by inner tubular surface with curved profile. Another invention of proposed set relates to two-stage gas turbine engine that comprises acoustic attenuation coat with circular section applied onto fan outer fairing and comprising curved profile. The latter is arranged between larger thickness zone and nozzle critical zone. Said thickness approximates to that of the coat front part and nozzle critical zone.

EFFECT: reduced noise in two-stage gas turbine engine rear part with no deterioration in engine operation.

5 cl, 4 dwg