Energy density effects on propulsive characteristics of water propellants for laser propulsion

In the case of low laser energy density, the vaporization process dominates the impulse production compared with other physical processes. One dimensional theoretical model was employed to describe the relationship among energy density and momentum coupling coefficients, specific impulse and the internal efficiency. Theoretical results show that there is an optimum energy density with maximum momentum coupling coefficient. The specific impulse increases with the increase of energy density. For a constant value of transmissivity, the internal efficiency approaches a constant as energy density increases. These theoretical analytical results can be helpful for further experimental works.