Variable geometry thruster

1. A propulsion system coupled to a vehicle, the propulsion system comprising:

a diffusing structure;

a conduit portion configured to introduce to the diffusing structure through a first passage a primary fluid produced by the vehicle, wherein the diffusing structure comprises a terminal end configured to provide egress from the propulsion system for the introduced primary fluid;

a first constricting element disposed adjacent a first wall, the first passage being defined by the first wall and the first constricting element; and

an actuating apparatus coupled to the first constricting element and configured to urge the first constricting element toward the first wall, thereby reducing a cross-sectional area of the first passage,

wherein the actuating apparatus comprises:

a first translating component configured to engage the first constricting element and configured to move translationally and perpendicularly relative to movement of the first constricting element; and

a first rotational component coupled to the first translating component and the first constricting element,

wherein movement of the first translating component rotates the first rotational component, thereby urging the first constricting element toward the first wall.

2. The propulsion system of claim 1 , wherein the conduit portion is further configured to introduce the primary fluid to the diffusing structure through a second passage, the second passage being defined by a second wall,

the propulsion system further comprises a second constricting element disposed adjacent the second wall, whereby the actuating apparatus is coupled to the second constricting element and configured to urge the second constricting element toward the second wall, thereby reducing a cross-sectional area of the second passage, and

the actuating apparatus further comprises:

a second translating component configured to engage the second constricting element and configured to move translationally;

a second rotational component coupled to the second translating component and configured to move rotationally; and

a lever element coupled to the first rotational component and the second rotational component and configured to rotate the first rotational component and the second rotational component in unison.

3. The propulsion system of claim 1 , further comprising a convex surface coupled to the diffusing structure, wherein the conduit portion is configured to introduce the primary fluid to the convex surface through the first passage.

4. A propulsion system coupled to a vehicle, the propulsion system comprising:

a diffusing structure;

an intake structure coupled to the diffusing structure and configured to introduce to the diffusing structure a secondary fluid accessible to the vehicle, the intake structure including a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle, the passage being defined by a wall, wherein the diffusing structure comprises a terminal end configured to provide egress from the propulsion system for the introduced primary fluid and secondary fluid;

a first constricting element disposed adjacent the wall; and

an actuating apparatus coupled to the constricting element and configured to urge the first constricting element toward the wall, thereby reducing a cross-sectional area of the passage,

wherein the actuating apparatus comprises:

a first translating component configured to engage the first constricting element and configured to move translationally and perpendicularly relative to movement of the first constricting element; and

a first rotational component coupled to the first translating component and the first constricting element,

wherein movement of the first translating component rotates the first rotational component, thereby urging the first constricting element toward the wall.

5. The propulsion system of claim 4 , wherein the conduit portion is further configured to introduce the primary fluid to the diffusing structure through a second passage, the second passage being defined by a second wall,

the propulsion system further comprises a second constricting element disposed adjacent the second wall, whereby the actuating apparatus is coupled to the second constricting element and configured to urge the second constricting element toward the second wall, thereby reducing a cross-sectional area of the second passage, and

the actuating apparatus further comprises:

a second translating component configured to engage the second constricting element and configured to move translationally;

a second rotational component coupled to the second translating component and configured to move rotationally; and

a lever element coupled to the first rotational component and the second rotational component and configured to rotate the first rotational component and the second rotational component in unison.

6. The propulsion system of claim 4 , further comprising a convex surface coupled to the diffusing structure, wherein the conduit portion is configured to introduce the primary fluid to the convex surface through the passage.

7. The propulsion system of claim 4 , wherein the primary fluid comprises compressor bleed air produced by a turbojet.

8. The propulsion system of claim 4 , wherein the diffusing structure is positioned downstream of a turbine of a turbocharger of the vehicle, and the primary fluid is supplied by a compressor of the turbocharger.

9. A vehicle comprising

a primary-fluid source;

a diffusing structure;

a conduit portion configured to introduce to the diffusing structure through a first passage a primary fluid produced by the source, wherein the diffusing structure comprises a terminal end configured to provide egress from the vehicle for the introduced primary fluid;

a first constricting element disposed adjacent a first wall, the first passage being defined by the first wall and the first constricting element; and

an actuating apparatus coupled to the first constricting element and configured to urge the first constricting element toward the first wall, thereby reducing a cross-sectional area of the first passage,

wherein the actuating apparatus comprises:

a first translating component configured to engage the first constricting element and configured to move translationally and perpendicularly relative to movement of the first constricting element; and

a first rotational component coupled to the first translating component and the first constricting element,

wherein movement of the first translating component rotates the first rotational component, thereby urging the first constricting element toward the first wall.

10. The vehicle of claim 9 , wherein the conduit portion is further configured to introduce the primary fluid to the diffusing structure through a second passage, the second passage being defined by a second wall,

the vehicle further comprises a second constricting element disposed adjacent the second wall, whereby the actuating apparatus is coupled to the second constricting element and configured to urge the second constricting element toward the second wall, thereby reducing a cross-sectional area of the second passage, and

the actuating apparatus further comprises:

a second translating component configured to engage the second constricting element and configured to move translationally;

a second rotational component coupled to the second translating component and configured to move rotationally; and

a lever element coupled to the first rotational component and the second rotational component and configured to rotate the first rotational component and the second rotational component in unison.

11. The vehicle of claim 9 , further comprising a convex surface coupled to the diffusing structure, wherein the conduit portion is configured to introduce the primary fluid to the convex surface through the first passage.