RINGED AIRFOIL WITH MIXING ELEMENTS
A shrouded fluid turbine includes a ringed airfoil having a leading edge, a trailing edge, an outer surface, an inner surface, and a body extending from the leading edge to the trailing edge. The shrouded turbine further includes a rotor surrounded by the ringed airfoil. The rotor is disposed downstream of the leading edge and about a central axis of the fluid turbine. The shrouded turbine further includes an aperture extending through the body of the ringed airfoil between the outer surface and the inner surface. The aperture is configured to mix a first fluid flow adjacent to the outer surface of the ringed airfoil and a second fluid flow downstream of the rotor.
1 . A shrouded fluid turbine comprising:
a ringed airfoil having a leading edge, a trailing edge, an outer surface, an inner surface, and a body extending from the leading edge to the trailing edge;
a rotor surrounded by the ringed airfoil, the rotor being disposed downstream of the leading edge and about a central axis of the fluid turbine; and
an aperture extending through the body of the ringed airfoil from the outer surface to the inner surface, the aperture disposed in the body to mix a first fluid flow adjacent to the outer surface of the ringed airfoil and a second fluid flow downstream of the rotor.
2 . The shrouded fluid turbine of claim 1 , wherein the aperture comprises one end disposed downstream of the rotor.
3 . The shrouded fluid turbine of claim 1 , further comprising a plurality of mixing elements disposed on the trailing edge of the ringed airfoil, each of the plurality of mixing elements being configured to further mix the first fluid flow adjacent to the outer surface of the ringed airfoil and the second fluid flow downstream of the rotor.
4 . The shrouded fluid turbine of claim 3 , wherein at least one of the plurality of mixing elements extends downstream of the rotor.
5 . The shrouded fluid turbine of claim 3 , wherein at least one of the plurality of mixing elements comprises a converging portion extending toward the central axis.
6 . The shrouded fluid turbine of claim 3 , wherein at least one of the plurality of mixing elements comprises a diverging portion extending away from the central axis.
7 . The shrouded fluid turbine of claim 3 , wherein at least one of the plurality of mixing elements comprises a converging portion extending toward the central axis and a diverging portion extending away from the central axis.
8 . The shrouded fluid turbine of claim 3 :
wherein a first one of the plurality of mixing elements comprises a converging portion extending toward the central axis,
wherein a second one of the plurality of mixing elements comprises a diverging portion extending away from the central axis, and
wherein the fluid turbine further comprises an ejector element disposed on the ringed airfoil proximal to a radial plane such that the ejector element is in fluid communication with the first one of the plurality of mixing elements, the radial plane extending outwardly from the central axis and passing through the first one of the plurality of mixing elements, the ejector element being configured to further mix the first fluid flow adjacent to the outer surface of the ringed airfoil and the second fluid flow downstream of the rotor.
9 . The shrouded fluid turbine of claim 8 , wherein at least a portion of the ejector element comprises a surface of the second one of the plurality of mixing elements.
10 . The shrouded fluid turbine of claim 3 , wherein at least one of the plurality of mixing elements is disposed on the inner surface of the ringed airfoil and comprises:
a converging portion extending toward the central axis; and
an ingress aperture adjacent to the inner surface of the ringed airfoil and configured to receive at least a portion of a third fluid flow adjacent to the inner surface.
11 . The shrouded fluid turbine of claim 10 , wherein the at least one of the plurality of mixing elements is configured to direct the received portion of the third fluid flow away from the inner surface.
12 . The shrouded fluid turbine of claim 3 :
wherein a first one of the plurality of mixing elements comprises a converging portion extending toward the central axis,
wherein a second one of the plurality of mixing elements comprises a diverging portion extending away from the central axis, and
wherein the fluid turbine further comprises an ejector element disposed on the ringed airfoil proximal to a radial plane such that the ejector element is in fluid communication with the second one of the plurality of mixing elements, the radial plane extending outwardly from the central axis and passing through the second one of the plurality of mixing elements, the ejector element being configured to further mix the first fluid flow adjacent to the outer surface and the second fluid flow downstream of the rotor.
13 . The shrouded fluid turbine of claim 1 , wherein the ringed airfoil further comprises a faceted trailing edge.
14 . The shrouded fluid turbine of claim 13 , wherein the ringed airfoil further comprises an outer surface and an inner surface, and wherein the faceted trailing edge is configured to mix, downstream of the rotor, a first fluid flow adjacent to the outer surface of the ringed airfoil and a second fluid flow adjacent to the inner surface of the ringed airfoil.
15 . The shrouded fluid turbine of claim 13 , wherein the faceted trailing edge comprises a facet extending away from the central axis.
16 . The shrouded fluid turbine of claim 15 , further comprising an ejector element disposed on the facet such that the ejector element is in fluid communication with the facet.
17 . The shrouded fluid turbine of claim 15 , wherein the ejector element is configured to mix, downstream of the rotor, the first fluid flow adjacent to the outer surface of the ringed airfoil and the second fluid flow adjacent to the inner surface of the ringed airfoil.
18 . A shrouded fluid turbine comprising:
a ringed airfoil having a leading edge, a trailing edge, an outer surface and an inner surface;
a rotor surrounded by the ringed airfoil, the rotor being disposed downstream of the leading edge and about a central axis of the fluid turbine;
a plurality of mixing elements disposed on the trailing edge of the ringed airfoil, each of the plurality of mixing elements being configured to mix a first fluid flow adjacent to the outer surface and a second fluid flow downstream of the rotor; and
a set of ejector elements disposed downstream of the rotor and at least partially surrounded by the ringed airfoil, the set of ejector elements comprising a converging portion extending toward the central axis and a diverging portion extending away from the central axis, each of the ejector elements being configured to mix a first portion of the second fluid flow downstream of the rotor and a second portion of the second fluid flow downstream of the rotor.
19 . The shrouded fluid turbine of claim 18 , wherein at least one of the plurality of mixing elements extends downstream of the rotor.
20 . The shrouded fluid turbine of claim 18 , wherein at least one of the plurality of mixing elements comprises a converging portion extending toward the central axis.
21 . The shrouded fluid turbine of claim 18 , wherein at least one of the plurality of mixing elements comprises a diverging portion extending away from the central axis.
22 . A shrouded fluid turbine comprising:
a ringed airfoil having a leading edge, a trailing edge, and an outer surface;
a rotor surrounded by the ringed airfoil, the rotor being disposed downstream of the leading edge and about a central axis of the fluid turbine;
a plurality of mixing elements disposed on the trailing edge of the ringed airfoil, each of the plurality of mixing elements being configured to further mix a first fluid flow adjacent to the outer surface of the ringed airfoil and a second fluid flow downstream of the rotor, a first one of the plurality of mixing elements comprising a converging portion extending toward the central axis, a second one of the plurality of mixing elements comprising a diverging portion extending away from the central axis; and
an ejector element disposed on the ringed airfoil proximal to a radial plane such that the ejector element is in fluid communication with the second one of the plurality of mixing elements, the radial plane extending outwardly from the central axis and passing through the second one of the plurality of mixing elements, the ejector element being configured to further mix the first fluid flow adjacent to the outer surface and the second fluid flow downstream of the rotor.
23 . The shrouded fluid turbine of claim 22 , wherein at least one of the plurality of mixing elements extends downstream of the rotor.