Pitch Stabilization for Surface Combatants

Abstract

ABSTRACTPitching is one of the most damaging motions for a ship, and is the obvious choice after rolling for reduction to improve ship operability. Although SWATHs or bigger monohulls have greater operability, they are often costly. Therefore, some method of stabilizing pitch on existing combatant hulls should be found. Historical research has shown that devices such as transom flaps and bow fins are ineffective or undesirable, but canted rudders show some promise. Using criteria for ASW and mobility operations, a destroyer hull equipped with large canted rudders using rudder pitch stabilization (RPS) was modeled on seakeeping evaluation programs. Its motions and operability were compared with a baseline hull (no RPS) as well as a SWATH and a larger Seakeeping Monohull. RPS reduced pitch motions 30–40% and improved operability 6–11% over the baseline hull, making its seakeeping performance comparable to the SWATH and Seakeeping Monohull. The use of high‐lift devices can provide the same performance with reasonably sized rudders. We recommend a program to further develop pitch stabilization using high‐lift canted rudders, including development of high‐lift foil technology and small‐scale validation of the RPS concept.