| 摘要 |
885,713. Jet propulsion nozzles. FAIREY CO. Ltd. June 19, 1958 [June 19, 1957], No. 19336/57. Class 110 (3). In a jet propulsion nozzle silencer which comprises a multi-point cross-tail nozzle whose discharge area is afforded by a number of narrow nozzle slots extending radially outwardly from an unobscured central discharge aperture, the nozzle slots being formed at the end of a corresponding number of flutes protruding radially from a tapered frusto-conical central passage which terminates in the central discharge aperture, the area of the central discharge aperture is between one tenth and one twentieth of the total discharge area. Preferably the area of the central unobscured discharge aperture should be between one tenth and one eleventh of the total silencer discharge area. The smallest number of slots that will provide the necessary discharge areas should be used. The silencer 10 comprises a convergent-open-ended frusto-conical tunnel 15 leading from a circular intake 16 to a small central discharge aperture 17, the walls of the tunnel being of fluted form. The flutes terminate in discharge slots 19 disposed around the aperture 17. The silencer is made up of a number of sheet metal plates which are bent and then welded to each other. These plates are welded at the inlet end to a ring 29 and at their outlet end to a ring 30. Webs 31 are also provided. In the arrangement shown the area of the discharge aperture 17 is a little less than one tenth of the total discharge area of the silencer. The actual dimensions of the nozzle are also given. |
