# US 10,480,866 B2 · Heat pipe with non-uniform cross-section > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,866 B2 - Document ID: US10480866B2 - Status: Granted - Kind: B2 - Application number: 15/398,790 - Filed: 2017-01-05 - Published: 2018-07-05 - Granted: 2019-11-19 - Earliest claimed: 2017-01-05 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Bruce Lee Drolen; Douglas H. Van Affelen; Arun Muley; Michael F. Stoia - Web page: https://patentgrep.com/patent/US10480866B2 ## CPC - F28D 15/0266: {with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers (F28D15/043 takes precedence)} - B33Y 80/00: Products made by additive manufacturing - F28D 15/0233: {the conduits having a particular shape, e.g. non-circular cross-section, annular (F28D15/0241, F28D15/0266 take precedence)} - F28D 15/0275: {Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores} - F28D 15/046: {characterised by the material or the construction of the capillary structure} - F28F 1/006: {with variable shape, e.g. with modified tube ends, with different geometrical features (F28F1/025, F28F1/06, F28F1/08, F28F9/16, F28F9/18 take precedence)} - F28F 1/40: the means being only inside the tubular element - F28F 13/08: by varying the cross-section of the flow channels - B23P 15/26: heat exchangers {or the like (making heat exchangers by methods covered by other subclasses B21D53/02)} - B23P 2700/09: Heat pipes - F28D 2021/0021: {for aircrafts or cosmonautics} - F28F 2215/04: Assemblies of fins having different features, e.g. with different fin densities - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) ## Abstract A heat pipe comprises a tube and protrusions. The tube has an internal surface, an external surface, and a length running from a first end to a second end. The protrusions are on the internal surface. A first cross-section of the protrusions at a first location of the length of the tube is different from a second cross-section of the protrusions at a second location of the length of the tube. The tube and the protrusions are monolithic. ## Claims ### Claim 1 A heat pipe comprising: a tube having an internal surface, an external surface, and a length running from a first end to a second end; a first planar flange located proximal to the first end relative to the second end, wherein a central axis for the tube is positioned between a plane of a first surface of the first planar flange and a plane of a second surface of the first planar flange, wherein the first surface and the second surface of the first planar flange extend from the external surface; a second planar flange located proximal to the second end relative to the first end, wherein the central axis is positioned between a plane of a third surface of the second planar flange and a plane of a fourth surface of the second planar flange, wherein the third surface and the fourth surface of the second planar flange extend from the external surface, and wherein the second planar flange is out of plane with the first planar flange; and protrusions continuously extending along the internal surface in a direction of the length of the tube, wherein at least one of a spacing, a size, or a shape of the protrusions changes continuously along the length between the first end of the tube and the second end of the tube, wherein the tube and the protrusions are monolithic. ### Claim 2 (depends on 1) The heat pipe of claim 1, wherein a height of at least one protrusion of the protrusions changes along the length of the tube. ### Claim 3 (depends on 1) The heat pipe of claim 1, wherein at least one protrusion of the protrusions terminates prior to the second end. ### Claim 4 (depends on 1) The heat pipe of claim 1, wherein the first end is an evaporator end, wherein the second end is a condenser end, and wherein a spacing of protrusions at the evaporator end is less than a spacing of protrusions at the condenser end. ### Claim 5 (depends on 1) The heat pipe of claim 1, wherein the protrusions taper from the first end to the second end. ### Claim 6 (depends on 1) The heat pipe of claim 1, wherein the tube, the protrusions, and the first planar flange and the second planar flange are monolithic. ### Claim 7 (depends on 6) The heat pipe of claim 6, wherein the first planar flange and the second planar flange are shaped and positioned to interface with a heat source and a heat sink that are not co-planar with each other. ### Claim 8 (depends on 7) The heat pipe of claim 7, wherein the first planar flange and the second planar flange are shaped and positioned to reduce the length of the tube. ### Claim 9 (depends on 1) The heat pipe of claim 1, wherein the tube is contoured to produce a shortest path from a heat source to a heat sink of a platform taking into account surrounding structures of the platform. ### Claim 10 (depends on 1) The heat pipe of claim 1, wherein the first end is an evaporator end, wherein the second end is a condenser end, and wherein a design of the protrusions restricts a heat load transferred to an evaporator when heat is applied to the condenser end. ### Claim 11 A heat pipe comprising: a tube having an internal surface, an external surface, and a length running from a first end to a second end; a first planar flange located proximal to the first end relative to the second end, wherein a central axis for the tube is positioned between a plane of a first surface of the first planar flange and a plane of a second surface of the first planar flange, wherein the first surface and the second surface of the first planar flange extend from the external surface; a second planar flange located proximal to the second end relative to the first end, wherein the central axis is positioned between a plane of a third surface of the second planar flange and a plane of a fourth surface of the second planar flange, wherein the third surface and the fourth surface of the second planar flange extend from the external surface, and wherein the second planar flange is out of plane with the first planar flange; and continuously variable protrusions on the internal surface, wherein the tube has a non-uniform cross-section such that a first cross-section of the protrusions at a first location of the length of the tube is different from a second cross-section of the protrusions at a second location of the length of the tube, and wherein the tube and the protrusions are monolithic. ### Claim 12 (depends on 11) The heat pipe of claim 11, wherein a height of at least one protrusion of the protrusions changes along the length of the tube. ### Claim 13 (depends on 11) The heat pipe of claim 11, wherein at least one protrusion of the protrusions terminates prior to the second end. ### Claim 14 (depends on 11) The heat pipe of claim 11, wherein the heat pipe provides a shortest three-dimensional path from a heat source to a heat sink. ### Claim 15 (depends on 11) The heat pipe of claim 11, wherein the protrusions form a plurality of continuously variable grooves. ### Claim 16 A method comprising: laying down material using additive manufacturing to form a heat pipe comprising a tube and protrusions, wherein the tube has an internal surface, an external surface, a length running from a first end to a second end, a first planar flange located proximal to the first end relative to the second end, a second planar flange located proximal to the second end relative to the first end, wherein the protrusions are continuously formed on the internal surface and form a plurality of continuously variable grooves, and wherein a first cross-section of the protrusions at a first location of the length of the tube is different from a second cross-section of the protrusions at a second location of the length of the tube; hot isotropic pressing the heat pipe to reduce porosity; and heat treating the heat pipe to increase strength. ### Claim 17 (depends on 16) The method of claim 16, wherein the tube is contoured to produce a shortest path from a heat source to a heat sink of a platform taking into account surrounding structures of the platform.