This paper describes the development of a high performance heat pipe designed to be used as a thermal bus in medium-size platforms and in the radiators of large-size space stations. The high performance is due to circumferential capillary grooves and the separation of the axial fluid flow by an extrusion inserted into the pipe.
In order to demonstrate the feasibility of the concept two test programs have been performed: The first was aimed to optimize the groove geometry by testing seven evaporator sections in a pumped two-phase loop. The tests resulted in maximum heat fluxes of 10.7 W/cm2 and heat transfer coefficients up to 1.35 W/cm2 K.
The second test program was performed on two full scale heat pipes of 1 m length under different tilt conditions. During then tests maximum axial heat loads up to 1200 W with radial heat fluxes of 15.9 W/cm2 could be achieved.
Under nominal operating conditions the typical heat transfer coefficients were larger than 19.8 W/cm2-K.