A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus are provided where heat exchange performance is improved, and drainage properties and resistance against frost formation are improved. A flat tube and a plurality of fins that are each a plate having a plate surface extending in a longitudinal direction and in a width direction orthogonal to the longitudinal direction are provided. The plate surface intersects a pipe axis of the flat tube, and the plurality of fins are arranged at an interval from one another. The plurality of fins each have a first spacer formed in the plate and maintaining the interval. The flat tube has a longitudinal axis of a section perpendicular to the pipe axis, and the longitudinal axis is inclined to the width direction by an inclination angle θ. The first spacer has a standing surface extending in a direction intersecting the plate surface.

A method and apparatus for heat transfer. In some embodiments, a heat transfer apparatus includes a body defining an inner volume; an inlet coupled to a vapor source; a coolant channel extending through the heat transfer apparatus; a condensing surface on which a vapor condenses, wherein the condensing surface is configured to cause the vapor to form as one or more drops on the condensing surface; and an actuator configured to excite the one or more drops at a resonant frequency of the one or more drops to remove the one or more drops from the condensing surface.

A method and apparatus for heat transfer. In some embodiments, a heat transfer apparatus includes a body defining an inner volume; an inlet coupled to a vapor source; a coolant channel extending through the heat transfer apparatus; a condensing surface on which a vapor condenses, wherein the condensing surface is configured to cause the vapor to form as one or more drops on the condensing surface; and an actuator configured to excite the one or more drops at a resonant frequency of the one or more drops to remove the one or more drops from the condensing surface.

A method for precise control of movement of a motive phase on a lubricant-impregnated surface includes providing a lubricant-impregnated surface, introducing the motive phase onto the lubricant-impregnated surface, and exposing the droplets to an electric and/or magnetic field to induce controlled movement of the droplets on the surface. The lubricant-impregnated surface includes a matrix of solid features spaced sufficiently close to stably contain the impregnating lubricant therebetween or therewithin. The motive phase is immiscible or scarcely miscible with the impregnating lubricant.

A method for precise control of movement of a motive phase on a lubricant-impregnated surface includes providing a lubricant-impregnated surface, introducing the motive phase onto the lubricant-impregnated surface, and exposing the droplets to an electric and/or magnetic field to induce controlled movement of the droplets on the surface. The lubricant-impregnated surface includes a matrix of solid features spaced sufficiently close to stably contain the impregnating lubricant therebetween or therewithin. The motive phase is immiscible or scarcely miscible with the impregnating lubricant.

A method for solidifying a polar substance, in particular water, is presented which comprises the steps of: providing a coolable, hydrophobic, preferably super-hydrophobic, condensation surface within an interior of a container; partially filling the container with a polar substance, preferably in liquid form, and an immiscible additive, preferably in liquid form, so that the condensation surface remains at least partially unsubmerged; cooling the hydrophobic condensation surface to a temperature T.sub.cond below a solidification temperature T.sub.solid of the polar substance; and removing solidified polar substance from the container.

A method for solidifying a polar substance, in particular water, is presented which comprises the steps of: providing a coolable, hydrophobic, preferably super-hydrophobic, condensation surface within an interior of a container; partially filling the container with a polar substance, preferably in liquid form, and an immiscible additive, preferably in liquid form, so that the condensation surface remains at least partially unsubmerged; cooling the hydrophobic condensation surface to a temperature T.sub.cond below a solidification temperature T.sub.solid of the polar substance; and removing solidified polar substance from the container.

Modified surfaces and methods of use thereof are provided for preventing or delaying onset of phase changes, such as condensation or frost formation. The invention relates to surfaces that increase the energy barrier to or driving force required for nucleation phase changes, such as, but not limited to, condensation and crystallization, and methods of use thereof, such as anti-fog glass applications and prevention of condensation on heat exchangers in systems that only require sensible cooling.

Modified surfaces and methods of use thereof are provided for preventing or delaying onset of phase changes, such as condensation or frost formation. The invention relates to surfaces that increase the energy barrier to or driving force required for nucleation phase changes, such as, but not limited to, condensation and crystallization, and methods of use thereof, such as anti-fog glass applications and prevention of condensation on heat exchangers in systems that only require sensible cooling.

A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus are provided where heat exchange performance is improved, and drainage properties and resistance against frost formation are improved. A flat tube and a plurality of fins that are each a plate having a plate surface extending in a longitudinal direction and in a width direction orthogonal to the longitudinal direction are provided. The plate surface intersects a pipe axis of the flat tube, and the plurality of fins are arranged at an interval from one another. The plurality of fins each have a first spacer formed in the plate and maintaining the interval. The flat tube has a longitudinal axis of a section perpendicular to the pipe axis, and the longitudinal axis is inclined to the width direction by an inclination angle θ. The first spacer has a standing surface extending in a direction intersecting the plate surface.