無人水下載台流體動力係數之拘束模型試驗量測分析探討

本研究使用PMM試驗量測分析系統，並精進其分析流程，使分析流程趨於更加完善與更具效率。本研究依據空中試驗時PMM機械阻尼之分析結果，說明水中試驗分析結果應扣除機械阻尼之必要。精進分析流程後，使用U-1水下無人載台作為流體動力係數量測分析對象，分別探討其縱向及橫向操縱運動安定性能。此外，並為了探討構型的影響，本研究比較了U-1載台之縱向流體動力係數結果與仿德製209型潛艦模型之縱向流體動力係數結果，以及比較U-1載台之縱向流體動力係數結果與U-1載台之橫向流體動力係數結果。並以三者構型之不同試圖解釋其流體動力係數以及三者安定性指數之差異：U-1載台之縱向安定性較209型潛艦之縱向安定性大，其原因為209型潛艦之艏翼過於接近前端、浮心位置過於後端、前後排水體積力臂差異不明顯；U-1載台之橫向安定性較縱向安定性大，其原因為受帆罩、艏翼之綜合影響。上述之比較結果可作為水下無人載台構型設計之參考。最後，以安定性時間常數之計算結果互相驗證U-1載台橫向與縱向安定性指數之分析結果，再一次確立此系統分析之可靠性及其應用性。

關鍵字

水下無人載台；流體動力係數；安定性指數；安定性時間常數； PMM

並列摘要

To measure the hydrodynamic coefficients of an underwater vehicle the PMM testing system of NTU is used in this study, and the analysis process is improved to make the the process more efficient and the results more reliable. Based on the analysis results of the PMM test in air, it is found that the mechanical damping is significant, and it’s necessary to deduct the mechanical damping from the analysis results of the PMM test in water. After improving the analysis process, the unmanned underwater vehicle U-1 is used to measure and analyze its hydrodynamic coefficients of longitudinal and transverse maneuvering motions. The stability of the longitudinal and transverse maneuvering motions of U-1 are discussed respectively. In order to discuss the influence of hull form and configuration to the hydrodynamic coefficients, the longitudinal and transverse hydrodynamic coefficients of the U-1 model as well as the longitudinal hydrodynamic coefficients of type 209 submarine of Germany are compared. Then the differences of the hydrodynamic coefficients and stability indexes among these three configurations are explained. The reasons that U-1 model is more stable than type 209 submarine of Germany can be concluded as follows: the bow fins of the type 209 submarine are closer to its front end, its center of buoyancy is more backward, and its arm of displacement volume of front part is quite close to that of rear part. The transverse stability index of the U-1 model is greater than its longitudinal stability index because of the comprehensive effects of the sail and the bow fins. Finally, according to the hydrodynamic coefficients of U-1 model, its stability time constants are also analyzed to verify the consistency of the analysis results of its longitudinal and transverse stability index. The reliability and applicability of the PMM testing system and analysis process are reconfirmed.