Heat pipe with axial wick

A heat pipe, comprising:

• an evaporator portion;
• a condenser portion;
• and
• at least one flexible portion sealingly coupled between the evaporator portion and the condenser portion, the at least one flexible portion comprising:
• a flexible tube comprising an interior volume and a plurality of inner edges;
• and
• a flexible separator plate comprising two lateral edges that are disposed proximate to the inner edges of the tube,
• wherein the interior volume comprises a gas-phase passage on a first side of the flexible separator plate and a liquid-phase artery on an opposing second side of the flexible separator plate, the separator plate further comprising a first plane that passes through the two lateral edges when the separator plate is flat,
• wherein the separator plate and flexible tube are configured such that the at least one flexible portion is flexible in at least a second plane that is perpendicular to the first plane,
• wherein the first plane comprises a centerline that is midway between the two lateral edges when the separator plate is flat,
• wherein the flexible portion is flexible in any plane that passes through the centerline of the separator plate,
• wherein the evaporator portion comprises a separation plate, a gas-phase passage, a liquid-phase artery, and a vent hole formed through the separator plate so as to connect the gas-phase passage to the liquid-phase artery, the vent hole comprising a diameter that is greater than or equal to a diameter of the largest circle that can be inscribed within the liquid-phase artery in a cross-section of the evaporator portion taken perpendicular to a centerline of the evaporator portion,
• wherein the flexible tube comprises a bellows tube that comprises a plurality of individual bellows each comprising an opening defined by the lateral edge of the separation plate and an inner surface of the individual bellows, and
• wherein each opening has a respective hydraulic diameter that is less than the diameter of the vent hole.