One dimensional effervescence modeling of an extraterrestrial submarine in the Saturn Titan Seas

摘要

An extraterrestrial submarine has been proposed to explore Saturn's moon Titan. A major design concern is the effect of effervescence on submarine operation. Because nitrogen gas has a relatively high solubility in the liquid ethane and methane seas, waste heat generated by the submarine power system may cause dissolved nitrogen gas to come out of solution. In a non-moving case, bubbles that form may interfere with science measurements. In a moving case, bubbles that form along the body may coalesce at the aft end of the craft and cause cavitation in the propellers. This paper presents a concise effervescence model as a function of the waste heat, location of submarine within the seas (liquid temperature and pressure), and contact angle between bubbles and submarine skin. Based on results, effervescence is a strong function of heat flux into the liquid as well as contact angle, possibly requiring limits on the power system or a redesign of the thermal management system. The current submarine operating waste heat flux is 370 W/m(2), which when compared to recent bubble incipience data suggests a small margin in safety factor, however.