碩士 / 國防大學理工學院 / 兵器系統工程碩士班 / 99 / The drag reduction for supercavitation is a new theory and approach that can conduct high-speed navigation of underwater vehicles. This mechanism of drag reduction is to generate a supercavity that can envelop the underwater vehicles, which would result in isolating the submerged body from water to avoid considerable frictional drag. A supercavity is influenced significantly by cavitator, many researches investigating the parametric effects of cavitator on supercavity have been proposed. However, most of these researches just paid attention on the effects of individual parameter; the assessments by using a systematized concept to integrate parameters are few. In this research, the software of computational fluid dynamics, Fluent 6.2, was used to simulate this study that is the steady, axis-symmetry natural supercavitation generated by cavitators with the types of cone, ellipse and trapezoid. The mixture multiphase model and the Singhal’s cavitation model were adopted to solve the RANS equation for the homogeneous supercavitation flow. The intelligent parameter design was implemented to obtain the best combination of multiquality characteristics that include length of supercavity, diameter of supercavity, and drag coefficient. In this work, we also used reduction percentage of quality loss (RPQL) to compare each optimum result. The effects of operating and environment factors were also taken into consideration. The results of simulation show that the underwater vehicle using supercavitation technology can obtain over 93% of drag reduction. Comparing the result by intelligent parametric design with the one by robust parametric design, the Principal Component Analysis’s reduction percentage of quality loss is 37.91% more than RPQL of Taguchi, for the intelligent parametric design, its reduction percentage of quality loss even increases up to 61.42%.
| Identifer | oai:union.ndltd.org:TW/099CCIT0157012 |
| Date | January 2011 |
| Creators | Wu, Wei-Ming, 吳偉銘 |
| Contributors | Wu, Sheng-Ju, 吳聖儒 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 147 |
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