Abstract: The blades (38) of a gas turbine engine fan rotor (32) are uniquely distributed in the rotor hub (48) so that combination tone noise attributable to one or more physical nonuniformities in the blades is mitigated. The invention recognizes that the frequency spectrum of the combination tone noise includes both decay prone harmonics and decay resistant harmonics and that allocation of acoustic energy into the decay prone harmonics and out of the decay resistant harmonics is effective for mitigating combination tone noise. In particular, the blades are distributed so that the spatial or circumferential spectrum of the physical nonuniformity is dominated by circumferential harmonics whose order is no greater than the order of the highest decay prone harmonic of the combination tone noise spectrum.

Abstract: A method disclosed]for balancing the fan rotor (10) of a turbine engine having a hub (12) with blades (16) extending radially therefrom includes the steps of determining (30) a penalty associated with each possible unique blade arrangement in which a limited number of blades is relocated from their initially assigned locations on the hub to new target locations. A subset of these arrangements is selected (34), the subset members being the arrangements having the lowest penalties. For each member of the subset, the penalty determination (36) is made for each possible unique blade arrangement in which a limited number of blades is relocated from their initial locations in each subset member to new target locations. If these latter penalty determinations identify an arrangement having a penalty less than that of any arrangement in the subset, the subset selection (34) and penalty determination steps (36) are repeated until no further reduction in penalty is observed.

Abstract: This invention relates to methods and apparatus for producing bakery goods, and in one embodiment useful in producing so-called rosettes, comprises forming means for forming the desired shape from batter, and cooking means in the form of a tank for containing heated oil, wherein the tank includes means for moving the bakery goods from the region of original exposure of the batter to the oil to means for turning the goods upside down and re-exposing them to the cooking oil, and means for removing the cooked goods from the cooking oil, wherein said means are arrayed in tandem and have associated means for causing formed products to be moved successively from each of said means to the next in sequence, the apparatus being adapted to maintain the forming means within prescribed temperature limits and substantially entirely free from cooking liquid upon being dipped in the batter.