ABSTRACT
The concept of using a closed two-phase heat transfer process was originally suggested by King and Perkins in a patent registered in the mid-nineteenth century [1-2]. In this conceptual design developed in 1867, a device referred to as the Perkins tube was proposed that utilized either single or two-phase processes to transfer heat from a furnace to a boiler. Shortly thereafter, Gay [3] obtained a patent for a device similar to the Perkins tube in which a number of vertical tubes were arranged with the evaporator located below the condenser. These devices, which were actually classified as a thermosyphon heat exchanger, laid the groundwork for the development of a heat pipe. Schmidt proposed the use of ammonia or carbon dioxide near their critical points for filling thermosyphon tubes, and Gaugler [4] proposed a two-phase closed thermosyphon tube, actually a thermosyphon heat transfer device incorporating a wick or porous matrix to provide capillary pumping to assist the return of the liquid to the evaporator. Trefethen [5] resurrected the idea of the heat pipe in connection with the space program in 1962. In 1963, Grover [6] filed a U.S patent application on behalf of the U.S Atomic Energy Commission for an evaporation-condensation device and used the term heat pipe for the first time. The heat pipe concept received relatively little attention until Grover et al. [7] published the results of an independent investigation, which reported the results of tests conducted on several prototypes, the first of which used water as a working fluid. These were soon followed by the development of a sodium heat pipe operating at temperatures in the 1100-K range. Since that time, heat pipes have been employed in a wide variety of applications. By 1969, there was significant interest on the part of NASA, Hughes Aerospace Corporation, TRW, Grumman Aerospace, and other aerospace companies, envisioning the use of these devices for regulating temperature in satellites and other spacecraft. Since then, many investigators have analyzed the conventional heat pipes using a variety of numerical and experimental techniques. Cotter [8], Chi [9], Dunn and Reay [10], Terpstra and Van Veen [11], Peterson [12], Faghri [13], Peterson [14], Ivanovskii [15], and Nouri-Borujerdi and Layeghi [16] have published several of these techniques, theories, and applications of different heat pipes.
