| 摘要 |
1401018 Gas turbine ducted fan engines BOEING CO 30 Oct 1972 [8 Nov 1971 16 Feb 1972] 32205/74 Divided out of 1401017 Heading F1J [Also in Division F2] The invention relates to a flow control system comprising means for inverting the respective positions of two separate flow patterns between the inlet and outlet of the system, there being means for switching the flow patterns whereby the flow patterns may be non-inverted. The system is shown applied to a gas turbine ducted fan engine in Fig. 1, the flow of air A from the fan 26 and flow of air B from the intake 28 are inverted in passing through the flow control unit 20 so that the flow A which is radially inward of flow B at the inlet 22 is radially outward of flow B at the outlet 24. The flow A discharges through propulsion nozzle 30. The flow B passes to the compressor 32 of the gas turbine engine. Thus the engine acts as a ducted fan engine. The downstream portion 24 of the flow control unit may be rotated so that the unit does not cause flow inversion, the inner flow A from the fan 26 now passing to the inlet of the compressor, and the outer flow B now passing straight through from the intake 28 to the outlet 30, the engine thus acting as a straight-through gas turbine jet engine. A flow control unit is shown in Fig. 3 and the cross-sections taken at the planes 3a, 3b, 3c, 3d, 3e, 3f are shown in the corresponding Figs. A passage A at the inner radius at the inlet section 3a, becomes passage A at the outer radius at the outlet section 3f; the cross-sections of the passage A changes from an arcuate sector at section 3a, to a pentagonal section at 3b, to a triangular section with apex outward at 3c, to a trapezium section extending from the inner wall 62 to the outer wall 60 at 3d, to a triangular section with apex inward at 3e, to a pentagonal section, finally to an arcuate sector at 3f. The control unit is divided at the section 3d, the downstream portion 58 being angularly movable with respect to the upstream portion 56 whereby the flows may be inverted or not. The control member may alternatively be built-up from a series of duct portions as shown in Fig. 6 each of which has a rectangular opening 140 at the inlet end, the rectangle having the longer side of horizontal, the duct changing to a triangular section at 142 then to a rectangular section at the outlet 144, the rectangle having the longer side vertical. In Fig. 7, two such duct members 126, 126" are joined end-to-end and a similar pair of members 126''', 126"" are disposed to co-operate therewith. The downstream members 126''', 126"" are arranged to move laterally with respect to the upstream members 126', 126 " for control. The area of the duct at any point along its length is constant. Many applications of the invention are described. |
