US 6,981,839 B2
Wind powered turbine in a tunnel
Leon Fan, 2707 Devonshire Dr., Carrollton, Tex. 75007 (US)
Filed on Mar. 09, 2004, as Appl. No. 10/796,369.
Prior Publication US 2005/0201855 A1, Sep. 15, 2005
Int. Cl. F03D 3/04 (2006.01)
U.S. Cl. 415—4.1 32 Claims
OG exemplary drawing
 
1. A wind turbine apparatus comprising:
a conduit extending along a longitudinal axis of the apparatus, the conduit comprising
an inlet portion at a first end of the longitudinal axis, the inlet portion having a main inlet opening,
an outlet portion at a second end of the longitudinal axis, the outlet portion having a main outlet opening, and
a middle portion located between the inlet and outlet portions, the inlet portion being fluidly connected to the outlet portion via the middle portion;
a rotor located in the middle portion of the conduit, the rotor comprising
a shaft extending along a rotational axis through the middle conduit portion, the rotor being adapted to rotate about the rotational axis, wherein the longitudinal axis intersects the rotational axis, wherein a rotor angle formed between the longitudinal axis and the rotational axis is between about 45 degrees and about 135 degrees, and wherein a longitudinal angle formed between the longitudinal axis and an overall wind flow direction for wind flowing through the conduit when the apparatus is being powered by a wind flow is less than about 45 degrees, and
blades extending from the shaft, the blades being located completely within the middle portion of the conduit;
a splitter located in the inlet portion of the conduit, so that the inlet portion of the conduit comprises an upper sub-tunnel and a lower sub-tunnel divided by the splitter, wherein the upper and lower sub-tunnels both feed into a middle portion inlet of the middle portion of the conduit, wherein the middle portion inlet is closer to the main inlet opening than a middle portion outlet of the middle portion along the longitudinal axis, and wherein the middle portion outlet is closer to the main outlet opening than the middle portion inlet along the longitudinal axis;
an upper interior wall of the middle conduit portion having a substantially circular plane shape that is substantially centered at the rotational axis, wherein an upper clearance gap is located between the blades and the upper interior wall of the middle conduit portion when the blades pass thereby; and
a lower interior wall of the middle conduit portion having a substantially circular plane shape that is substantially centered at the rotational axis, the lower interior wall of the middle conduit portion being opposite and facing the upper interior wall of the middle conduit portion, wherein a lower clearance gap is located between the blades and the lower interior wall of the middle conduit portion when the blades pass thereby, and wherein side clearance gaps are located between sides of the blades and the middle conduit portion.