Fluid resonator

Apparatus for producing vibrations in a fluid flow, comprising:

• at least one cylindrical member adapted to be mounted in the fluid flow with its longitudinal axis parallel to the direction of fluid flow, wherein said cylindrical member is provided with at least a partial double wall and the area between the walls of said double wall being at least partially closed near its downstream end.

Apparatus for producing vibrations in a fluid flow, comprising:

• a pipe or conduit for fluid flow;
• a plurality of cylindrical members, each having a leading and trailing edge, mounted in series in the conduit in the fluid flow path with their longitudinal axes parallel to the direction of fluid flow and allowing fluid flow on both sides of the members, and said plurality of cylindrical members being separated from each other by a predetermined distance in the direction of fluid flow such that a separation is provided between the trailing edge of the preceeding cylindrical members and the leading edge of succeeding cylindrical members, a plurality of concentrically mounted cylindrical members, said plurality of concentric cylindrical members varying in length, and means for concentrating and directing fluid with force towards the leading edge of at least the first of said cylindrical members, the leading edge of said cylindrical member undergoing interaction with the fluid flow whereby vibrations are induced in the fluid.

Apparatus for producing vibrations in a fluid flow, comprising:

• a pipe or conduit for a fluid flow;
• a plurality of cylindrical members, each having a leading and trailing edge, mounted in series in the conduit in the fluid flow path with their longitudinal axes parallel to the direction of fluid flow and allowing fluid flow on both sides of the members, and said plurality of cylindrical members being separated from each other by a predetermined distance in the direction of fluid flow such that a separation is provided between the trailing edge of preceeding cylindrical members and the leading edge of succeeding cylindrical members, at least one additional cylindrical member mounted concentric with at least one of said plurality of cylindrical members, at least one additional cylindrical member mounted concentrically with another one of said plurality of cylindrical members wherein said two concentrically mounted cylindrical members are mounted in the flow path in series and means for concentrating and directing fluid with force towards the leading edge of at least the first of said cylindrical members, the leading edge of said cylindrical member undergoing interaction with the fluid flow whereby vibrations are induced in the fluid.

Apparatus for use in the recovery of oil from oil formations, comprising:

• at least one cylindrical member mounted concentrically within an oil well bore hole casing or equivalent structure in an oil well bore hole with its longitudinal axis parallel to the direction of the fluid flow and allowing fluid flow on both sides of said member, the leading edge of said cylindrical member interacting with the fluid flow for producing vibration in the fluid flow through the bore hole.