The objective of the activity is to develop an interconnected heat pipe network with pipes of adapted sizes, heat transport capacity and heat flux capability to reduce thermal gradients and thermal interfaces. In order to evaluate and demonstrate the performance improvements a scaled engineering model of a heat pipe network, as needed for active antenna array applications, shall bedesigned, manufactured and tested.
Targeted Improvements: Enabling the thermal management of large active transmit antenna, e.g. direct radiating antenna.
Description: The use of active antennas is increasing, as well as their complexity. Thermal management of anactive antenna is problematic since the antenna generates large amount of heat in very localised areas. Complex active thermal solutions with a mechanical pump system could be a solution. However, these systems are very expensive, massive, and complex. A complex passive two-phase structure could be more suited for this type of application. Conventional heat pipe networks use two types of heatpipes. Longheat pipes distribute the heat along the length of the panel. Crossing heat pipes, mounted on top of the long heat pipes, uniformlyspread the temperature between the long heat pipes.
Unfortunately, this mounting technique creates large temperature differences between heat pipes due to the various thermal interfaces. In order to reduce the thermal gradients, a 2D two-phase structure can be constructed to eliminate the thermal interfaces. Furthermore, an active antenna may have areas that are difficult to access and to thermally connect. Hence in this activity, smaller and complex heat pipe sections will be investigated to transport heat from the active sources to a larger collecting heat pipe.
The collecting heat pipe will transport heat directly to a radiator, or it will be used as interface to a loop heat pipe, which will collect the waste heat and transport it to the radiators. A scaled engineering model ofa multi scale heat pipe network will be studied, designed, manufactured and tested, where smaller diameter heat pipes collect the waste heat from components and transport it to a larger collecting two-phase manifold that would transport it to the radiator.