Patent ID: 9249755
Filing Date: 2016-02-02
CPC Classification: A45D,F02K,F05B,F05D,Y10T

Claim Text:
1. A method for defining a shape of an annular cowl including an external wall and an internal wall defining a convergent-divergent nozzle of a longitudinal axis of a turbomachine, either about said longitudinal axis, or about a casing of revolution about said longitudinal axis, said nozzle comprising, in a direction in which gases flow, a convergent part connected, at a throat, to a divergent part a downstream free end of which includes scallops delimiting noise-reducing chevrons distributed in a circumferential direction, the method comprising: defining the divergent part of the nozzle beforehand using the following two portions: attributing an initial value to dimensional parameters defining the chevrons and the cowl in said divergent part; and applying an optimization algorithm to the parameters thus initialized in order to define the shape of the convergent-divergent nozzle equipped with the chevrons that satisfies predefined conditions regarding at least one defined performance criterion; wherein the second portion corresponding to the chevrons is forced to comprise: