초록 ▼

A vortex generating apparatus includes: a member to contact with a flow of a fluid to form a stagnation point and a first and a second separation points on a periphery of a cross section of the member parallel to the flow; a disturbance applying unit to apply a disturbance to an upstream side of the

A vortex generating apparatus includes: a member to contact with a flow of a fluid to form a stagnation point and a first and a second separation points on a periphery of a cross section of the member parallel to the flow; a disturbance applying unit to apply a disturbance to an upstream side of the first separation point to cause part of a boundary layer of the flow to adhere; and a controller to temporally control the application of the disturbance to change an adhesion distance from the stagnation point to the first separation point so as to generate a dynamic stall vortex.

대표청구항 ▼

1. A vortex generating method, comprising: disposing a wing in a flow of a fluid to form a stagnation point and a first and a second separation points on a periphery of a cross section of the wing parallel to the flow, at the stagnation point the fluid flowing in, and the first and the second separa

1. A vortex generating method, comprising: disposing a wing in a flow of a fluid to form a stagnation point and a first and a second separation points on a periphery of a cross section of the wing parallel to the flow, at the stagnation point the fluid flowing in, and the first and the second separation points being followed by a first and a second separation region respectively;while the wing has an attack angle larger than a static stalling angle, applying a disturbance to an upstream side of the first separation point to cause part of a boundary layer of the flow to adhere; andwhile the wing has the attack angle larger than the static stalling angle, controlling the application of the disturbance to change a position of the first separation point, change an adhesion distance from the stagnation point to the first separation point, and swing the boundary layer to generate a vortex corresponding to a dynamic stall vortex, the vortex corresponding to the dynamic stall vortex having an axis in a wing span direction of the wing. 2. The vortex generating method according to claim 1, wherein the disturbance is applied by a disturbance applying unit, the disturbance applying unit comprises: a first electrode configured to be in contact with the fluid;a second electrode configured to be in contact with the fluid via a dielectric; anda power source configured to apply a voltage between the first and second electrodes to generate discharge between the first and second electrodes. 3. The vortex generating method according to claim 2, wherein the first and second electrodes are disposed on the upstream side and a downstream side or on the downstream side and the upstream side of the flow of the fluid respectively. 4. The vortex generating method according to claim 1, wherein the disturbance is applied by a disturbance applying unit, the disturbance applying unit comprises: a vibration generator configured to apply vibration to the fluid; anda power source configured to cause the vibration generator to generate the vibration. 5. The vortex generating method according to claim 1, wherein the disturbance is applied by a disturbance applying unit, the disturbance applying unit comprises: an acoustic wave generator configured to apply an acoustic wave to the fluid; anda power source configured to cause the acoustic wave generator to generate the acoustic wave. 6. The vortex generating method according to claim 1, wherein the vortex corresponding to the dynamic stall vortex has an axis perpendicular to a direction of the flow and vorticity whose sign is the same as a sign of vorticity in the boundary layer, the same sign meaning the same rotation directions of vorticity. 7. The vortex generating method according to claim 1, wherein the wing is attracted to the vortex corresponding to the dynamic stall vortex having a pressure less than fluid around the vortex corresponding to the dynamic stall vortex, when the vortex corresponding to the dynamic stall vortex passes near the wing. 8. The vortex generating method according to claim 1, wherein the fluid, which has a pressure less than fluid around the vortex corresponding to the dynamic stall vortex, is attracted to the wing when the vortex corresponding to the dynamic stall vortex passes near the wing. 9. The vortex generating method according to claim 1, wherein the controlling the application of the disturbance intermittently generates a plurality of vortices, thereby reducing a wake flow region. 10. The vortex generating method according to claim 1, wherein the controlling the application of the disturbance intermittently generates a plurality of vortices, thereby reducing a fluid noise. 11. The vortex generating method according to claim 1, wherein the controlling the application of the disturbance intermittently generates a plurality of vortices different in interval. 12. A vortex generating method, comprising: disposing a wing in a fluid and forming a state where a boundary layer of a flow of the fluid is separated and is not adhering, between a separation point and a trailing edge of the wing;while the wing has an attack angle larger than a static stalling angle, applying a disturbance to the boundary layer of the flow at or on an upstream side of the separation point to cause adhesion of the boundary layer and changing an adhesion distance from the separation point;while the wing has the attack angle larger than the static stalling angle, generating a vortex corresponding to a dynamic stall vortex in the fluid in accordance with the change of the adhesion distance; andwhile the wing has the attack angle larger than the static stalling angle, controlling to intermittently apply the disturbance to the upstream side of the separation point of the fluid on a surface of the wing having the separation point so as to generate the vortex corresponding to the dynamic stall vortex. 13. The vortex generating method according to claim 12, wherein the disturbance is applied by applying a voltage between a first electrode in contact with the fluid and a second electrode in contact with the fluid via a dielectric to cause discharge between the first and second electrodes. 14. The vortex generating method according to claim 12, wherein the disturbance is applied by applying vibration or an acoustic wave to the fluid.