Disclosed are systems and techniques for increasing heat transfer from a substrate to a working fluid. The systems may include a substrate comprising a plurality of grooves or cavities on at least one external surface. The system may also include an infusing liquid filling at least a majority of the plurality of grooves. The system may also include a working fluid configured to flow parallel to the external surface.

Provided is an apparatus for removing thermal stratification generated by turbulent penetration by using a rotation ring. The apparatus removes thermal stratification formed in a branch pipe branching from a main pipe through which a high-temperature fluid flows, the apparatus including: a hollow body portion coupled to the branch pipe; a plurality of first electromagnets provided to be spaced apart from each other in a circumferential direction of the body portion; a controller configured to sequentially change polarities of the plurality of first electromagnets; and a rotation ring including a plurality of second electromagnets having either an N polarity or an S polarity, the rotation ring being rotatably coupled to the body portion, wherein, when the polarities of the plurality of first electromagnets are sequentially changed, the rotation ring rotates according to a magnetic force of the plurality of first electromagnets and the plurality of second electromagnets.

Provided is an apparatus for removing thermal stratification generated by turbulent penetration by using a rotation ring. The apparatus removes thermal stratification formed in a branch pipe branching from a main pipe through which a high-temperature fluid flows, the apparatus including: a hollow body portion coupled to the branch pipe; a plurality of first electromagnets provided to be spaced apart from each other in a circumferential direction of the body portion; a controller configured to sequentially change polarities of the plurality of first electromagnets; and a rotation ring including a plurality of second electromagnets having either an N polarity or an S polarity, the rotation ring being rotatably coupled to the body portion, wherein, when the polarities of the plurality of first electromagnets are sequentially changed, the rotation ring rotates according to a magnetic force of the plurality of first electromagnets and the plurality of second electromagnets.

Systems and methods are described herein to implement transverse momentum injection at low frequencies to directly modify large-scale eddies in a turbulent boundary layer on a surface of an object. A set of transverse momentum injection actuators may be positioned on the surface of the object to affect large-scale eddies in the turbulent boundary layer. The system may include a controller to selectively actuate the transverse momentum injection actuators with an actuation pattern to affect the large-scale eddies to modify the drag, fluid mixing, heat transfer, and/or other interactions of the fluid flow with the surface. In various embodiments, the transverse momentum injection actuators may be operated at frequencies less than 10,000 Hertz.

A vortex generator device in channels or ducts that makes it possible to take advantage of the wingtip vortex that is formed in the aerodynamic profiles as a consequence of having a finite wingspan. These aerodynamic profiles have one or two marginal edges from which the wingtip vortex emerges, causing the appearance of an oscillatory movement that subjects the particles that travel with the current to an ascending-descending cycle, and has the fundamental advantage that transverse speeds are produced to the main current, with hardly any pressure drops.

A vortex generator device in channels or ducts that makes it possible to take advantage of the wingtip vortex that is formed in the aerodynamic profiles as a consequence of having a finite wingspan. These aerodynamic profiles have one or two marginal edges from which the wingtip vortex emerges, causing the appearance of an oscillatory movement that subjects the particles that travel with the current to an ascending-descending cycle, and has the fundamental advantage that transverse speeds are produced to the main current, with hardly any pressure drops.

Apparatuses for flowing multiple fluids in a single channel while substantially maintaining fluid separation are disclosed. In one configuration, the apparatus includes a first internal surface portion with an affinity to a first fluid and a second internal surface portion with an affinity to a second fluid. In another configuration, the apparatus includes a first fluid channel portion, a second fluid channel portion wrapped helically around the first fluid channel portion, and an opening therebetween. Also disclosed is an apparatus for maintaining substantially even fluid flow in fluid pathways having a first flow resistor portion, a second flow resistor portion, and a fluid channel therebetween.

Apparatuses for flowing multiple fluids in a single channel while substantially maintaining fluid separation are disclosed. In one configuration, the apparatus includes a first internal surface portion with an affinity to a first fluid and a second internal surface portion with an affinity to a second fluid. In another configuration, the apparatus includes a first fluid channel portion, a second fluid channel portion wrapped helically around the first fluid channel portion, and an opening therebetween. Also disclosed is an apparatus for maintaining substantially even fluid flow in fluid pathways having a first flow resistor portion, a second flow resistor portion, and a fluid channel therebetween.

Disclosed herein are a method and a system for forming an air layer over a portion of an engineered surface, wherein the air layer is formed with a reduced flux and preferentially steering gas away from, or toward, a specific location by way of a hydrophobic surface, a hydrophilic surface, and/or a structured surface. Moreover, disclosed are a method and a system for recovering or separating a portion of the gas or other fluid layer.

A method of starting up flow of viscous oil in a pipeline, wherein the pipeline has an inlet and an outlet and wherein the viscous oil is initially stationary within the pipeline, includes supplying water to a first section of the pipeline through an inflow control device; initiating a flow of viscous oil within the first section towards the outlet by pressurising the water; supplying water to a second section of the pipeline through a further inflow wherein the first section is closer to the outlet of the pipeline than the second section; and initiating a flow of viscous oil within the second section towards the outlet by pressurising the water.