会员体验
专利管家(专利管理)
工作空间(专利管理)
风险监控(情报监控)
数据分析(专利分析)
侵权分析(诉讼无效)
联系我们
交流群
官方交流:
QQ群: 891211   
微信请扫码    >>>
现在联系顾问~
热词
    • 9. 发明授权
    • Airfoil boundary layer control means
    • 翼型边界层控制装置
    • US3005496A
    • 1961-10-24
    • US83562759
    • 1959-08-24
    • HILLER AIRCRAFT CORP
    • NICHOLS JOHN B
    • B64C21/04B64C27/18B64C27/46
    • B64C27/463B64C21/04B64C27/18B64C2230/04B64C2230/06B64C2230/16B64C2230/28Y02T50/166
    • 898,203. Boundary layer control on helicopter blades. HILLER AIRCRAFT CORPORATION. Aug. 22, 1960 [Aug. 24, 1959], No. 28934/60. Class 4. A helicopter rotor blade, adjustably mounted for pitch change, has boundary layer control means including operating means therefor comprising a first member fixed on the blade, and a second member movable on the blade under the control of restraining means operative in response to conditions of flight independent of the angle of attack of the blade, relative movement between the first and second members operating the boundary layer control means. Fig. 2 shows a rotor blade tip, a hollow spar 3 receiving compressed air through the hollow rotor shaft from a compressor or gas turbine engine, and communicating through valves (not shown) with ducts 9 leading to a trailing edge slot 10. The valves are controlled by a rod 12 secured to an arm 13 on which are a small aerofoil 14 and a mass balance 15. The aerofoil 14 keeps the arm 13 aligned with the relative wind direction W, and when the angle of attack of the retreating blade increases, rotation of the blade relatively to rod 12 opens the valve so that an air jet 10a is discharged from slot 10, to increase the lift of the blade and delay the onset of stall by energising the boundary layer. In an alternative, the rod 13 has two masses, one at each end so that the rod remains parallel to the tip path plane by gyroscopic effect as the rotor rotates. In either embodiment, power consumption is minimized by discharging compressed air only when needed. The compressor may be driven from the gearbox of an engine driving the rotor shaft.