A vortex-controlled variable flow resistance device ideal for use in a backpressure tool for advancing drill string in extended reach downhole operations. The characteristics of the pressure waves generated by the device are controlled by the growth and decay of vortices in the vortex chamber(s) of a flow path. The flow path includes a switch, such as a bi-stable fluidic switch, for reversing the direction of the flow in the vortex chamber. The flow path may include multiple vortex chambers, and the device may include multiple flow paths. A hardened insert in the outlet of the vortex chamber resists erosion. This device generates backpressures of short duration and slower frequencies approaching the resonant frequency of the drill string, which maximizes axial motion in the drill sting and weight on the bit. Additionally, fluid pulses produced by the tool enhance debris removal ahead of the bit.

This invention relates to a vortex station and method for producing a vortex similar to one of a group consisting of dust-devils and waterspouts. The apparatus comprises a ground platform forming a base for the vortex station, a plurality of vanes to direct an air flow into a vortex station and about the vortex station in a substantially swirling manner, at least one wind turbine disposed near the centre of said vortex station, in a path of a concentrated air flow, wherein the movement of the air in the vortex station is such that an atmospheric buoyancy vortex is created in the centre of the vortex station, a supply of a working fluid (e.g. water) to the vortex station at or near the centre of the vortex station such that the air is of a saturated condition or an at least partially saturated condition with the working fluid (e.g. water), the working fluid (e.g. water) supplied at a sufficient quantity or amount so as to assist with maintaining buoyancy and stability of a vortex created.

This invention relates to a vortex station and method for producing a vortex similar to one of a group consisting of dust-devils and waterspouts. The apparatus comprises a ground platform forming a base for the vortex station, a plurality of vanes to direct an air flow into a vortex station and about the vortex station in a substantially swirling manner, at least one wind turbine disposed near the centre of said vortex station, in a path of a concentrated air flow, wherein the movement of the air in the vortex station is such that an atmospheric buoyancy vortex is created in the centre of the vortex station, a supply of a working fluid (e.g. water) to the vortex station at or near the centre of the vortex station such that the air is of a saturated condition or an at least partially saturated condition with the working fluid (e.g. water), the working fluid (e.g. water) supplied at a sufficient quantity or amount so as to assist with maintaining buoyancy and stability of a vortex created.

Variable flow resistance systems can be used to regulate fluid flow in various applications, particularly within a subterranean formation. A variable flow resistance system can comprise a chamber configured to induce rotational motion of a fluid flowing therethrough, a fluid inlet coupled to the chamber, and a fluid outlet coupled to the chamber that allows the fluid to exit through at least a sidewall of the chamber. If desired, a plurality of the chambers can be connected in series fluid flow communication with one another.

A mixing apparatus including a mixing region can have an inlet and an outlet. The mixing region can be operable to couple with a solution housing, thereby defining a mixing chamber. A stem can extend from a surface of the mixing region and the inlet can be disposed at a distal end of the stem. A wing can disposed at a proximal end of the stem and adjacently engaged with the surface of the mixing region and have a leading edge and a trailing edge.

A mixing apparatus including a mixing region can have an inlet and an outlet. The mixing region can be operable to couple with a solution housing, thereby defining a mixing chamber. A stem can extend from a surface of the mixing region and the inlet can be disposed at a distal end of the stem. A wing can disposed at a proximal end of the stem and adjacently engaged with the surface of the mixing region and have a leading edge and a trailing edge.

Pressure oscillations or acoustic loads over an open type cavity having a front face an upper edge of which constitutes a leading edge and having a rear face an upper edge of which constitutes a trailing edge are reduced by applying curvature to the rear face so as to present a convex curved surface internal to the cavity. In one embodiment, a cross-section through a longitudinal axis of the convex curved surface describes part of an ellipse.

This invention relates to a vortex station and method for producing a vortex similar to one of a group consisting of dust-devils and waterspouts. The apparatus comprises a ground platform forming a base for the vortex station, a plurality of vanes to direct an air flow into a vortex station and about the vortex station in a substantially swirling manner, at least one wind turbine disposed near the centre of said vortex station, in a path of a concentrated air flow, wherein the movement of the air in the vortex station is such that an atmospheric buoyancy vortex is created in the centre of the vortex station, a supply of a working fluid (e.g. water) to the vortex station at or near the centre of the vortex station such that the air is of a saturated condition or an at least partially saturated condition with the working fluid (e.g. water), the working fluid (e.g. water) supplied at a sufficient quantity or amount so as to assist with maintaining buoyancy and stability of a vortex created.

Example apparatus for regulator heat transfer are disclosed. An example apparatus includes a housing including an inlet, an outlet, a first valve, and a stem disposed therein. The example apparatus includes a vortex generator disposed in the housing. A fluid is to flow from the inlet through the vortex generator. The example apparatus includes a second valve disposed in the vortex generator. In the example apparatus, the vortex generator is to generate heat prior to the fluid flowing through the second valve to the outlet. The stem is to control the first valve and the second valve to regulate an amount of the heat conveyed to the first valve.

This invention relates to a vortex station and method for producing a vortex similar to one of a group consisting of dust-devils and waterspouts. The apparatus comprises a ground platform forming a base for the vortex station, a plurality of vanes to direct an air flow into a vortex station and about the vortex station in a substantially swirling manner, at least one wind turbine disposed near the centre of said vortex station, in a path of a concentrated air flow, wherein the movement of the air in the vortex station is such that an atmospheric buoyancy vortex is created in the centre of the vortex station, a supply of a working fluid (e.g. water) to the vortex station at or near the centre of the vortex station such that the air is of a saturated condition or an at least partially saturated condition with the working fluid (e.g. water), the working fluid (e.g. water) supplied at a sufficient quantity or amount so as to assist with maintaining buoyancy and stability of a vortex created.