Sodium vapor flow regimes and pressure losses on cathode side of multitube AMTEC cell

Abstract

A model was developed to calculate the vapor pressure losses and characterize the vapor flow regimes on the cathode side of multitube vapor-anode AMTEC cells, with internal chevrons radiation shields and TiN electrodes. Results showed that the vapor flow on the cathode side of the AMTEC cells was typically in the transition regime, and that the pressure losses due to the chevrons shield constituted about 50% of the total pressure loss. Such an increase in the vapor pressure losses, however, decreased the cell electrical power output by only about 5%, because the concentration losses in the cell were small compared to the charge-exchange polarization and internal ohmic losses.