The Effect of Changing Launch Package Mass on the Electromechanical Conversion Efficiency of Railguns

The changing mass of the launch package affects efficiency. It is not necessarily clear which mass should be used for the calculation of kinetic energy, since the mass changes. The analysis clarifies these and other uncertainties, and equations for efficiency with mass transfer effects were derived. The effects of friction and pre-acceleration were also analyzed, and mass transfer was found to have a similar effect on efficiency as friction. These equations were then compared to a mathematical simulation of an arbitrary fictitious railgun. These results agreed with the equations to at least 11 significant figures.