| 摘要 |
A mechanism for linearizing an open, vertically directed, high-speed air flow, generated by a propeller rotating about a vertical axis, includes a vertical cylindrical element mounted above and coaxially with the rotating propeller and a plurality of radially oriented vertically planar guide vanes supported at their radially outside ends in such a manner that ambient air can flow radially inward below and above the propeller. For large cross-section air-flows and improved elimination of swirl components from the flow, a second set of shorter radial guide vanes is provided in alternation with the vanes that are connected to the cylindrical element. A net structure is disposed above the guide vane structure for use of the invention in a system for producing a relatively large cross-section linearized flow to enable free-fall simulation exercises by one or more participants, to enable trainers to stand close to the free-falling participants. The preferred form of the net includes two orthogonally interwoven sets of cables each of which is individually tensioned at opposite ends and is entirely free of extraneous constraints, e.g., knots or swages, at cable intersections. This net structure, because of its freedom from extraneous flow impedances at cable intersections allows free passage of the upward air flow and serves to further improve the linearization thereof.
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