초록 ▼

A porous surface on an aircraft structure driven with oscillating positive and negative pressures is used as an active control device for attenuating negative aerodynamic interactions. The porous surfaces can be driven with positive and negative pressures either continuously or when predetermined fl

A porous surface on an aircraft structure driven with oscillating positive and negative pressures is used as an active control device for attenuating negative aerodynamic interactions. The porous surfaces can be driven with positive and negative pressures either continuously or when predetermined flight conditions are present. The porous surfaces can be used on rotor blades to reduce BVI noise in descent flight conditions. The porous surfaces can be configured on rotor blades for affecting blade variable twist in accordance with various flight conditions, and can further be incorporated for reducing rotor hub vibrations as well. Porous surfaces placed on aerodynamic surfaces below the rotor blades of a tiltrotor aircraft can attenuate or eliminate download and fountain flow conditions. When placed on the trailing edges of a tip jet-exhaust driven rotor blade, the porous surfaces of the present invention can supplement the tip jet momentum of the exhaust to thereby reduce an amount of exhaust needed to drive the rotor blade.

대표청구항 ▼

A porous surface on an aircraft structure driven with oscillating positive and negative pressures is used as an active control device for attenuating negative aerodynamic interactions. The porous surfaces can be driven with positive and negative pressures either continuously or when predetermined fl

A porous surface on an aircraft structure driven with oscillating positive and negative pressures is used as an active control device for attenuating negative aerodynamic interactions. The porous surfaces can be driven with positive and negative pressures either continuously or when predetermined flight conditions are present. The porous surfaces can be used on rotor blades to reduce BVI noise in descent flight conditions. The porous surfaces can be configured on rotor blades for affecting blade variable twist in accordance with various flight conditions, and can further be incorporated for reducing rotor hub vibrations as well. Porous surfaces placed on aerodynamic surfaces below the rotor blades of a tiltrotor aircraft can attenuate or eliminate download and fountain flow conditions. When placed on the trailing edges of a tip jet-exhaust driven rotor blade, the porous surfaces of the present invention can supplement the tip jet momentum of the exhaust to thereby reduce an amount of exhaust needed to drive the rotor blade. o the combustion chamber of the engine. When the power source activates the oscillating magnetic field in the coil and applies same to the magnetostrictive portion of the needle, ultrasonic energy is applied to the pressurized liquid. The method involves retrofitting a conventional injector with a needle having a magnetostrictive portion and with a ceramic valve body surrounded by wound wire coils configured and disposed to subject the magnetostrictive portion of the needle to ultrasonically oscillating magnetic fields. 38, 19811200, Martin, 239/102.2; US-4340563, 19820700, Appel et al.; US-4372491, 19830200, Fishgal; US-4389999, 19830600, Jaqua; US-4405297, 19830900, Appel et al.; US-4418672, 19831200, Muller et al.; US-4434204, 19840200, Hartman et al.; US-4466571, 19840800, Muhlbauer; US-4475515, 19841000, Mowbray; US-4496101, 19850100, Northman; US-4500280, 19850200, Astier et al.; US-4521364, 19850600, Norota et al.; US-4526733, 19850700, Lau; US-4529792, 19850700, Barrows; US-4563993, 19860100, Yamauchi et al.; US-4576136, 19860300, Yamauchi et al.; US-4590915, 19860500, Yamauchi et al.; US-4627811, 19861200, Greiser et al.; US-4644045, 19870200, Fowells; US-4663220, 19870500, Wisneski et al.; US-4665877, 19870500, Manaka et al.; US-4715353, 19871200, Koike et al.; US-4716879, 19880100, Takayama et al.; US-4726522, 19880200, Kokubo et al.; US-4726523, 19880200, Kokubo et al.; US-4726524, 19880200, Ishikawa et al.; US-4726525, 19880200, Yonekawa et al.; US-4742810, 19880500, Anders et al.; US-4756478, 19880700, Endo et al.; US-4793954, 19881200, Lee et al.; US-4815192, 19890300, Usui et al.; US-4852668, 19890800, Dickinson, III et al.; US-4974780, 19901200, Nakamura et al.; US-4986248, 19910100, Kobayashi et al.; US-4995367, 19910200, Yamauchi et al.; US-5017311, 19910500, Furusawa et al.; US-5032027, 19910700, Berliner, III; US-5068068, 19911100, Furusawa et al.; US-5110286, 19920500, Gaysert et al.; US-5112206, 19920500, Stewart; US-5114633, 19920500, Stewart; US-5154347, 19921000, Vijay; US-5160746, 19921100, Dodge, II et al.; US-5169067, 19921200, Matsusaka et al.; US-5179923, 19930100, Tsurutani et al.; US-5226364, 19930700, Fadner; US-5269981, 19931200, Jameson et al.; US-5330100, 19940700, Malinowski; US-5382400, 19950100, Pike et al.; US-5531157, 19960700, Probst; US-5564402, 19961000, Poschl; US-5801106, 19980900, Jameson; US-5803106, 19980900, Cohen et al.; US-5868153, 19990200, Cohen et al.; US-5892315, 19990400, Gipson et al.; US-5900690, 19990500, Gipson et al.; US-6010592, 20000100, Jameson et al.; US-6020277, 20000200, Jameson; US-6036467, 20000300, Jameson; US-6053424, 20000400, Gipson et al.; US-6062489, 20000500, Tokumaru,