潛艦胴體截面設計對於水下操縱性能的影響

IMPACT OF SUBMARINE CROSS-SECTION SHAPE ON UNDERWATER MANEUVERING PERFORMANCE

本研究以DARPA的SUBOFF模型為基礎，在相同排水量條件下，設計類超橢圓形狀截面胴體，並使用計算流體力學軟體計算潛艦的流體動力係數，如黏滯力曲線係數、附加質量與水動力中心。再使用操船模擬模式求解潛體運動方程式，模擬潛體在主軸轉速40 RPM與90 RPM的條件下，自靜止起步直至穩定航速後，進行迴旋試驗與Z形試驗的結果，得以獲得迴旋試驗與Z型試驗的特徵值。本研究發現在搭配相同附屬物的條件下，類超橢圓形狀與圓形截面胴體在水平迴旋運動與Z形運動的表現相似：在低速航行下，本研究設計船形對比原始SUBOFF船形的水平迴旋運動各項特徵值變化均小於2.5%，Z形運動特徵值變化小於5.0%；高速航行下，水平迴旋運動各項特徵值變化小於2.5%，Z形運動特徵值變化小於5.3%。在低速與高速航行下，類超橢圓形狀胴體截面幾何參數與各項迴旋運動特徵值呈正相關性，與各項Z形運動特徵值呈負相關性。比較本研究的三種類超橢圓形狀截面胴體後發現，較為方正的類超橢圓形狀截面胴體，其迴旋性能較差，但操縱性能較優異。

This study is to investigate the impact of the section form of bare hull on the maneuvering characteristics by using a computational fluid dynamics method coupled with a maneuvering simulation approach. The target hull form is based on a DARPA SUBOFF model with a variation in the section form. The hydrodynamic coefficients of bare hull, such as viscos drag coefficient, added mass coefficient and aerodynamic center, are predicted by a computational fluid dynamics approach. The predicted hydrodynamic coefficients are adopted in the maneuvering calculation to simulate the turning and zigzag test under specific conditions, i.e., at the shaft speed of 40 RPM and 90 RPM. Under the condition of 40 RPM, the difference of turning and zigzag test characteristics between the target hull form and original SUBOFF hull form is under 2.5% and 5.0%, respectively. Under the condition of 90 RPM, the difference of turning and zigzag test characteristics is under 2.5% and 5.3%, respectively. This numerical result suggests that the performance of an underwater vehicle in the turning and zigzag test is slightly influenced for the investigated hull form when compared to the reference hull with the same appendage employed. In addition, the turning test characteristics are positively correlated to the target hull form parameter, while the zigzag test characteristics are negatively correlated to the target hull form parameter. After the performance comparison among three hull forms proposed in this study, the hull form with a circular cross section delivers a better turning performance but a worse maneuvering performance than the one with a non-circular cross section.