Modeling of loop heat pipes with applications to spacecraft thermal control

A new and valuable addition to the heat transfer community, a heat transport device known as a Loop Heat Pipe (LHP), is discussed in this work. This body of research is very important as the LHP is becoming increasingly prevalent in heat transfer applications. U.S. commercial use of the Loop Heat Pipe will begin on the next generation of communications satellites being developed and built by Hughes Space and Communications Company. These satellites take advantage of the passive nature of the LHP, requiring no external means of pumping, along with its ability to transport large quantities of heat over significant distances. This device comes to the heat transfer community at an ideal time as the aerospace industry is demanding higher and higher power payloads and this increasing power must be handled by the most efficient means possible. The LHP is also being investigated for uses in ground-based applications such as solar collectors and computer cooling. This dissertation focuses on experimentation conducted with a space-based satellite application in mind, however, results are applicable to other implementations as well. The LHP is a descendant of the conventional heat pipe. The LHP utilizes the advantages of the conventional heat pipe while overcoming some of the conventional heat pipe's inherent disadvantages. This dissertation serves as a complete body of work on this new device; from background and literature review on the development and history of the LHP, to important computer simulation and experimental work, both ground-based and space-based, performed on the LHP in an effort to gain a thorough understanding of the workings of the Loop Heat Pipe and to investigate novel new applications for the LHP such as the ability to control the temperature of an entire spacecraft payload with a minute fraction of the heater power once required. The LHP introduces important new opportunities to the heat transfer community and the research presented here furthers the knowledge and understanding of this breakthrough device.