Heat exchanger with oscillating flow

Claim 2

A heat exchange apparatus comprising: at least one conduit having first and second ends and providing a primary coolant channel for a primary coolant, the at least one conduit being exposed to an incident heat flux; and means for imparting an oscillatory flow of primary coolant having sufficient frequency to establish a velocity boundary layer in the primary coolant at walls of the at least one conduit, wherein said imparting means imparts an oscillating flow of primary coolant to establish a boundary layer having a thickness which is proportional to the square root of the ratio of the kinematic viscosity to the circular frequency of oscillations of the primary coolant and establishes a nearly constant velocity slug flow of primary coolant in the cross-wise direction of the at least one conduit.

Claim 3

The heat exchange apparatus according to claim 1, wherein said imparting means imparts the oscillatory flow of primary coolant at the first conduit end and further comprising means for removing primary coolant at the second conduit end during one-half cycle of oscillation and for introducing primary coolant at the second conduit end during the other half-cycle.

Claim 4

The heat exchange apparatus according to claim 1, wherein said removing and introducing means comprises a chamber located at the second conduit end, an intake valve located in the chamber and connected to a primary coolant supply line, and an exhaust valve located in the chamber, wherein said intake and exhaust valves are actuated sequentially to coincide with half-cycles of oscillation of the oscillatory flow of primary coolant in the at least one conduit.

Claim 5

The heat exchange apparatus according to claim 1, wherein the at least one conduit comprises a fluid reservoir section exposed to an incident heat flux and an elongated conduit section fluidly connected thereto, and further comprising at least one radiating fin connected to the elongated conduit section to dissipate heat therefrom.

Claim 6

A heat exchange apparatus according to claim 1, wherein the at least one conduit comprises a plurality of tubes disposed side by side.

Claim 7

A heat exchange apparatus according to claim 5, wherein the plurality of tubes are bent to form an apex at which the incident heat flux is directed.

Claim 8

A heat exchange apparatus according to claim 6, wherein the apex of the plurality of tubes is disposed in a leading edge of an aerodynamic structure.

Claim 9

A heat exchange apparatus according to claim 1, wherein the at least one conduit comprises a plurality of channels formed in a sheet of structural material.

Claim 10

A heat exchange apparatus according to claim 8, wherein the sheet of structural material is layered, stacked and oriented in various directions.

Claim 11

A heat exchange apparatus according to claim 1, wherein the primary coolant is a liquid.

Claim 12

A heat exchange apparatus according to claim 1, wherein the means for imparting oscillating flow is an electromagnetic pump, the primary coolant is a liquid metal, and the at least one conduit is a closed loop.

Claim 13

A heat exchange apparatus according to claim 1, wherein the means for imparting oscillating flow is a fluidic oscillator.

Claim 14

The heat exchange apparatus according to claim 1, wherein said means for imparting an oscillatory flow comprises: a pump for creating a pressure head in the primary coolant; channel means for communicating primary coolant from the pump to the first end of the at least one conduit; and means disposed in the channel means for creating flow oscillations of the primary fluid, thereby imparting oscillating flow through the at least one conduit.

Claim 15

A heat exchange apparatus according to claim 13, wherein the means for creating flow oscillations is a pair of synchronized two way valves.

Claim 16

A heat exchange apparatus according to claim 13, wherein the means for creating flow oscillations is a fluidic oscillator.

Claim 17

A heat exchange apparatus according to claim 14, wherein said means for creating flow oscillation comprises a first manifold connecting the first end of the at least one conduit and a second manifold connecting the second end of the at least one conduit, a first channel connected to the first manifold, a second channel connected to the second manifold, a third channel also connected to the first manifold, and a fourth channel also connected to the second manifold, wherein one of the valves switches flow from either the first or second channels, and the other valve switches flow from either the third or fourth channels.

Claim 18

A heat exchange apparatus according to claim 16, wherein the first, second, third and fourth channels are provided with check valves to prevent back flow at the pair of two way valves.

Claim 19

A heat exchange apparatus comprising: at least one conduit having first and second ends and providing a primary coolant channel for a primary coolant; means for imparting an oscillatory flow of primary coolant from the first end of the at least one conduit such that the flow has sufficient frequency in the at least one conduit to establish a velocity boundary layer in the primary coolant at walls of the at least one conduit; wherein said imparting means imparts an oscillating flow of primary coolant to establish a boundary layer having a thickness which is proportional to the square root of the ratio of the kinematic viscosity to the circular frequency of oscillations of the primary coolant and establishs a nearly constant velocity slug flow of primary coolant in the cross-wise direction of the at least one conduit; and a plenum of gas with a condensable phase is connected to the second end of the at least one conduit, wherein the plenum is exposed to heat and heat is removed from plenum condensate-fluid by the primary coolant.

Claim 20

A heat exchange apparatus comprising: at least one conduit having first and second ends and providing a primary coolant channel for a primary coolant; means for imparting an oscillatory flow of primary coolant from the first end of the at least one conduit such that the flow has sufficient frequency in the at least one conduit to establish a velocity boundary layer in the primary coolant at walls of the at least one conduit; wherein said imparting means imparts an oscillating flow of primary coolant to establish a boundary layer having a thickness which is proportional to the square root of the ratio of the kinematic viscosity to the circular frequency of oscillations of the primary coolant and establishs a nearly constant velocity slug flow of primary coolant in the cross-wise direction of the at least one conduit; and a plenum of gas with a condensable phase is connected to the second end of the at least one conduit, wherein the plenum is exposed to heat and heat is removed from plenum condensate-fluid by the primary coolant.

Claim 21

The heat exchange apparatus according to claim 18, wherein the at least one conduit is inclined toward said means for imparting the oscillatory flow.

Claim 22

The heat exchange apparatus according to claim 18, further comprising means for flowing a secondary coolant over an outer surface of the at least one conduit.

Claim 23

A heat exchange apparatus according to claim 18, wherein the at least one conduit is exposed to an external incident heat flux.