Abstract: An energy harvester including a stand supporting the energy harvester in a fluid flow, i.e. a stream or current; at least one bluff body extending from the stand and positioned substantially perpendicular to the fluid flow, wherein each bluff body moves relative to the stand at least in a direction perpendicular to the fluid flow, wherein sufficient flow causes oscillating movement of the bluff body; and an electrical generator coupled to the stand and coupled to at least one bluff body converting the oscillating movement to electrical power, wherein the rate of electrical power generation per movement of the bluff body (or harvesting) is varied throughout a range of amplitudes of the oscillation of the bluff body and wherein the harvesting rate of at least one amplitude of the body oscillation is greater than the harvesting rate of at least one lower amplitude of the body oscillation.

Abstract: A fluid flow induced oscillating energy harvester includes a stand supporting the harvester in a fluid flow; a support member mounted for movement relative to the stand in a direction perpendicular to the flow direction; a bluff body positioned substantially perpendicular to the flow direction and pivotally mounted to the support member at a position off-center from the center of mass of the bluff body, wherein sufficient fluid flow causes an oscillating movement of the bluff body and the support member relative to the stand; and an electrical generator coupled to the support member and configured to convert oscillating movement of the support member to electrical power. The harvester may include a support member spring supporting the support member for oscillation about a support member rest position wherein the support member spring exhibits a higher stiffness at higher oscillation amplitudes of the bluff body and the support member.

Abstract: An energy harvester including a stand supporting the energy harvester in a fluid flow, i.e. a stream or current; at least one bluff body extending from the stand and positioned substantially perpendicular to the fluid flow, wherein each bluff body moves relative to the stand at least in a direction perpendicular to the fluid flow, wherein sufficient flow causes oscillating movement of the bluff body; and an electrical generator coupled to the stand and coupled to at least one bluff body converting the oscillating movement to electrical power, wherein the rate of electrical power generation per movement of the bluff body (or harvesting) is varied throughout a range of amplitudes of the oscillation of the bluff body and wherein the harvesting rate of at least one amplitude of the body oscillation is greater than the harvesting rate of at least one lower amplitude of the body oscillation.

Abstract: A fluid flow induced oscillating energy harvester includes a stand supporting the harvester in a fluid flow; a support member mounted for movement relative to the stand in a direction perpendicular to the flow direction; a bluff body positioned substantially perpendicular to the flow direction and pivotally mounted to the support member at a position off-center from the center of mass of the bluff body, wherein sufficient fluid flow causes an oscillating movement of the bluff body and the support member relative to the stand; and an electrical generator coupled to the support member and configured to convert oscillating movement of the support member to electrical power. The harvester may include a support member spring supporting the support member for oscillation about a support member rest position wherein the support member spring exhibits a higher stiffness at higher oscillation amplitudes of the bluff body and the support member.