Pau Simpson Crusafon
Thermal management of satellites in space is known to be a complex issue which is often constrained by weight and volume. Radiators are a good solution, but as the power demand of electronics and other systems on board continues to grow, it is important to improve these radiators by increasing their area and efficiency while reducing their weight. Existing radiator solutions do not combine a lightweight structure made of carbon fiber that can be folded and deployed with embedded fluid channels. Making a carbon fiber structure that can fold and hold fluid inside of it is a complex problem that could reduce weight while increasing area. This thesis explores the possibility of combining these solutions by making a radiator panel out of two carbon-fiber shells that are bonded together to create a single-phase fluid channel. The geometry of the channel is created in a way that allows the panel to fold into a stowed configuration to occupy less launch volume. This proof of concept was validated through an integrated approach, cross-checking an analytical model, an ANSYS Fluent simulation, and a thermal-vacuum test against one another. A copper twin was manufactured for use as a baseline comparison. Pressure and folding tests were conducted on the carbon-fiber panel to characterize its folding capabilities. Two different folding behaviors were observed, with a minimum fold diameter of 50mm for a local folding panel which holds pressure up to 17psig before failing at 18psig, and a flexing panel that folds to 80mm and holds up to 57psig before failing at 58psig. For inlet temperatures of 90 C at a room temperature vacuum environment, the prototype can reject 19.5W of heat. A longer prototype is estimated to reject 56.6 W at the same test conditions, with the possibility of manufacturing larger prototypes with the same discovered manufacturing process. Comparing heat rejection by mass to the copper benchmark shows a 3x advantage for the carbon-fiber radiator. This concept proves the ability to combine three properties into one prototype: a lightweight carbon-fiber panel that folds and deploys, holds a working fluid without leaking, and rejects measurable heat.