ARRANGEMENTS, DUCT ARRANGEMENTS AND METHODS

Abstract

According to the present disclosure there is provided a liquid flow influencing duct arrangement comprising: a first duct section arranged to receive a liquid flow therethrough, the first duct section defining a first direction through the first duct section from a liquid inlet end to a liquid outlet end; a second duct section defining a second direction through the second duct section from a liquid inlet end to a liquid outlet end, the second duct section comprising a vortex generator surface, wherein the vortex generator surface is arranged to induce vortices in the liquid flow through the first duct section, wherein the duct arrangement further comprises a rotor housed in one of the duct sections.

Description

Claims

1. A liquid flow influencing duct arrangement comprising: a first duct section arranged to receive a liquid flow therethrough, the first duct section defining a first direction through the first duct section from a liquid inlet end to a liquid outlet end;a second duct section defining a second direction through the second duct section from a liquid inlet end to a liquid outlet end, the second duct section comprising a vortex generator surface, wherein the vortex generator surface is arranged to induce vortices in the liquid flow through the first duct, section; anda rotor housed in one of the first or second duct sections.

2. The duct arrangement according to claim 1, wherein the rotor is housed in the first duct section.

3. The duct arrangement according to claim 1, wherein the vortex generator surface comprises a series of projections.

4. The duct arrangement according to claim 1, wherein the vortex generator surface is a ring.

5. The duct arrangement according to claim 1, wherein the second duct section is attached to, supported by and/or is formed integrally with, the first duct section.

6. The duct arrangement according to claim 1, wherein the second duct section is aligned with and/or is coaxial with the first duct, section.

7. The duct arrangement according to claim 1, wherein the rotor is a propeller and/or turbine rotor.

8. The duct arrangement according to claim 1, wherein the second duct section is provided upstream of the rotor along the first direction.

9. The duct arrangement according to claim 1, wherein the second duct section is provided upstream of the first duct section along the first direction.

10. The duct arrangement according to claim 1, wherein the second duct section is provided at a leading edge of the first duct section.

11. The duct arrangement according to claim 1, wherein the projections of the vortex generator surface project in a direction substantially opposite to the first direction.

12. The duct arrangement according to claim 1, wherein the first duct section interacts with the liquid flow to induce a first set of liquid properties, and the vortex generator surface interacts with the liquid flow to induce a second set of liquid properties, the second set of liquid properties comprising an increase in the vorticity magnitude of the liquid flow.

13. The duct arrangement according to claim 1, wherein the vortex generator surface is configured to induce a plurality of spatially separated vortices in the liquid flow.

14. A watercraft comprising the duct arrangement according to claim 1.

15. A method of influencing liquid flow, the method comprising: generating vortices in a liquid flow using a second duct section comprising a vortex generating surface; andreceiving the liquid flow in a first duct, section;a rotor being housed in one of the first or second duct sections.

16. The method according to claim 15, wherein the first duct section and the second duct section are separately formed, and the second duct section is attached to the first duct section.

17. The duct arrangement according to claim 1, wherein the first duct section and second duct section are separately formed, and the second duct section is attached to the first duct section.

18. A liquid flow influencing duct arrangement comprising: a first duct section arranged to receive a liquid flow therethrough, the first duct section defining a first direction through the first duct section from a liquid inlet end to a liquid outlet end;a second duct section defining a second direction through the second duct section from a liquid inlet end to a liquid outlet end, the second duct section comprising a vortex generator surface, wherein the vortex generator surface is arranged to induce vortices in the liquid flow through the first duct section; anda rotor housed in one of the first or second duct sections;wherein the first duct section and the second duct section are separately formed, and the second duct section is attached to the first duct section.

19. The duct arrangement according to claim 18, wherein the second duct section is attached to the first duct section by a bolt or screw.

20. The duct arrangement according to claim 13, wherein the spatially separated vortices are periodic vortices.