Effect of Stern Fin Sizing and Longitudinal Positioning on the Horizontal Stability of an Unconventional AUV

Maneuvering of AUVs are important to the control and power system design of the craft. This research study proposes to understand the effect of stern fin sizing and positioning on the horizontal linear course stability of an unconventional AUV named ‘Seppia’. The ability to maneuver a submerged craft is inversely related to its stability. The craft, ‘Seppia’ was designed with the intent of maximizing endurance for a mission of forward motion at a constant low velocity. The unconventionality in design of this craft is that the propulsion is through a duct along the axial length of the hull. This mission requires the craft to have a relatively higher stability in contrast to maneuverability. To achieve this, stern fixed fins are designed for the craft. The craft is then virtually simulated to obtain the stability index
$G_{h}$
. The effect of area and longitudinal position on
$G_{h}$
on stability is the contribution of this article.