- 學位論文
水下滑翔機於不同NACA翼型與翼位之水動力分析
Hydrodynamic analysis of an underwater glider with different NACA airfoil shapes and positions
摘要
本論文完成水下滑翔機不同機翼翼型及翼位之分析研究，選用NACA0006、NACA0008及NACA00010對稱型機翼之比較，並且對該滑翔機進行流體動力學模擬分析。考慮流速0.25 m/s、0.5 m/s、0.75 m/s、1 m/s及1.25 m/s的速度，攻角由10°至-10°，使用ANSYS Fluent並採用k-epsilon RNG紊流模型作模擬分析，進而探討升力係數、阻力係數及升阻比。在三種NACA翼型模擬之結果中選出最佳升阻比之NACA對稱型機翼，藉以進行下一個階段不同翼位之探討，並找出運動最佳化位置模擬之研究。 本研究結果發現，在所探討之參數範圍，升阻比隨速度增加而增加，最為理想的翼型為NACA0008，最佳升阻比是在攻角8°，流速由0.25 m/s至1.25 m/s，機翼升阻比增加了52.62%，在0.5 m/s流速攻角8°時與平板機翼相比NACA0006與NACA0010機翼升阻比提升了16.77%，NACA0008機翼升阻比提升了22.05%，說明NACA翼型之升阻比都高於平板機翼具有最佳的升阻比；機翼在不同翼位研究結果發現，最佳翼位為中間翼位，由於前段翼位的曲線圖很接近中間翼位曲線，使得前段翼位的升阻比也有不錯的表現，結論可從曲線圖看出在機翼不同翼位下產生的升阻力係數也不相同，曲線集中在機身中間翼位與前段翼位，而後段翼位的成效不如預期。
並列摘要
This thesis has completed the analysis and study of different airfoil shapes and airfoil positions of an underwater glider. The comparison of NACA0006, NACA0008 and NACA00010 symmetrical airfoils was selected, and the hydrodynamic simulation analysis of this glider is carried out. Velocities of 0.25 m/s, 0.5 m/s, 0.75 m/s, 1 m/s and 1.25 m/s and angles of attack 10° to -10° were considered, and ANSYS-Fluent using k-epsilon RNG turbulence were used. The model was simulated and analyzed, and then the lift coefficient, drag coefficient, and lift-to-drag ratio were discussed. The NACA symmetrical airfoil with the best lift-to-drag ratio was selected from the results of three NACA airfoil simulations, so that the next stage of the study of different wing positions and the study of the simulation of the optimal position of the movement were selected. The results show that the lift-drag ratio increase with the increase of speed for the parameters considered. The best airfoil is NACA0008. The best lift-to-drag ratio is at the angle of attack of 8°. When the velocity changes from 0.25 m/s to 1.25 m/s, the lift-to-drag ratio of the airfoil increases by 52.62%. Compared with the flat airfoil, the lift-drag ratio of NACA0006 and NACA0010 airfoils increase by 16.77%, and the lift-drag ratio of NACA0008 airfoil increased by 22.05%, indicating that the lift-to-drag ratio of any NACA airfoil is higher than that of a flat airfoil. It was found from the results for different airfoil positions that the best airfoil position is in the middle. Since the curve of the front airfoil position is very close to the curve of the middle airfoil position, the lift-to-drag ratio of the front airfoil position also has a good performance. The conclusion can be seen from the curves that the lift and drag coefficients generated under different airfoil positions are different. The curves are concentrated in the middle and front airfoil positions of the fuselage, while the performance of the rear airfoil position is not as expected.