Artery heat pipes for space-power systems

High-temperature liquid-metal heat pipes are being developed as part of the SP-100 space power system. The operating temperature of the heat pipes is in the 1400 to 1500 K range and the design power level is 15kW per pipe. Baseline design for the heat pipes is an arterial configuration using a fine mesh screen for the arteries and distribution wick. Performance predictions for this configuration have been conducted and the designs characterized as a function of artery geometry, distribution wick thickness, porosity, pore size, and permeability. In parallel with this effort the screen wick materials have been characterized experimentally in terms of pore size and permeability. As a verification of the performance predictions a heat pipe employing two tubular arteries and a distribution wick of tightly compacted, 150-mesh molybdenum screen has been assembled and operated with sodium as a working fluid