{
  "$type": "site.standard.document",
  "description": "A propulsion system and methods are presented. A substantially tubular structure (102) comprises a central axis (104) through a longitudinal geometric center, and a first fan (108) rotates around the central axis, and comprises a first fan hub (110) and first fan blades (112). The fan hub (108) is…",
  "path": "/patents/974913",
  "publishedAt": "2014-05-14T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B64C11/001",
    "BOEING CO [US]"
  ],
  "textContent": "A propulsion system and methods are presented. A substantially tubular structure (102) comprises a central axis (104) through a longitudinal geometric center, and a first fan (108) rotates around the central axis, and comprises a first fan hub (110) and first fan blades (112). The fan hub (108) is rotationally coupled to the substantially tubular structure (102), and the first fan blades (112) are coupled to the first fan hub (110) and increase in chord length with increasing distance from the first fan hub (108). A second fan (118) is rotationally coupled to the substantially tubular structure (102) and rotates around the central axis and contra-rotates relative to the first fan (108). Second fan blades (118) are coupled to the second fan hub (120), and a nacelle (124) circumscribing the first fan (108) and the second fan (118) is coupled to and rotates with the first fan (108).",
  "title": "Rotational annular airscrew with integrated acoustic arrester"
}