Asymmetrical wake and propulsor effects on control surface effectiveness on AUVs

Abstract

This study considers the influences of wake asymmetries and propulsor effects on the forces and moments created by control surfaces. Traditional quasi-steady state-space models developed for autonomous underwater vehicles (AUVs) tend to neglect these effects. Reynolds-averaged Navier-Stokes (RANS) simulations were used to assess the impact of asymmetrical inflow due to forward appendages as well as changes in the flow field created by an operating propeller on control surface effectiveness. For the AUV tested, substantial asymmetries in the flow field near the upper and lower rudders create significant differences in their respective performances. This discrepancy between the rudders has the potential to create considerable and unsuspected maneuvering reactions. The presence of the propeller was also seen to noticeably influence the performance of the control surfaces.