A liquid-fuel sheet injected into the combustor of gas turbine engines is deformed and atomized as a result of the complex interactions between the liquid and air flows. However, the effects of the fluid properties and velocities of the gas and liquid on liquid sheet oscillation have not been clarified yet. In this paper, we performed two-dimensional (2-D) numerical simulations of an oscillating liquid sheet using a volume tracking method to investigate the effects of densities, velocities, viscosities and momentums of the gas and liquid phases on the growth rate and wavelength of the liquid sheet oscillation. As a result, we obtained the following conclusions. The oscillation of a liquid sheet is suppressed by the atomizer lip, which forms a wake in its downstream. The gas velocity gradient at the gas-liquid interface is a dominant factor in the growth of liquid sheet oscillation, which depends not mainly on gas velocity but on liquid velocity due to the lip. Gas and liquid viscous forces slightly reduce liquid sheet oscillation. The wavelength of the oscillation is in inverse proportion to the square root of the momentum flux ratio.
The solar power sail is an original Japanese concept in which electrical power is generated by thin-film solar cells on the sail membrane. It can generate sufficient electric power to drive the high-specific ion engines in the outer planetary region. We propose a landing or sample return mission to explore a Jupiter Trojan asteroid directly using solar power sail. After rendezvousing with a Trojan asteroid, a lander separates from the solar power sail-craft to collect surface and underground samples, and perform an in-situ analysis in Plan-A/B. In addition, the lander delivers samples to the solar power sail-craft to return the sample in Plan-B. This paper shows a system design for the solar power sail-craft and introduces the latest mission analysis.