本研究以交叉式雙旋翼 (Intermeshing Rotors)無人直升機(Unmanned Helicopters) 的應用探討，計算交叉式旋翼直升機的互擾誘導動力效率因子(Interference-Induced Power Factor, int)，且針對交叉式雙旋翼無人直升機型的設計研究。
交叉式雙旋翼無人機型研究將以三個部份來探討：旋翼的互擾誘導動力效率因子、外型與無人機應用；外型參考Kaman Aircraft’s K-1200(K-MAX)與Kaman Aircraft’s HH-43B(Huskie)的設計，旋翼軸傾角(Rotors Shaft Angle)與旋轉中心距離(Rotors Center Distances)為重要決定參數，在無人直升機中，結構因素使無人機型可將旋轉中心增加，軸傾角縮小，減少額外損耗的功率。
旋翼的互擾誘導動力效率因子為直升機效率計算的重要參數，可用來比較旋翼所損耗的能量，以同軸雙旋翼(Coaxial Rotors)與橫列雙旋翼(Tandem Rotors)的動量理論運算為基礎，並且在同軸與橫列式雙旋翼的動量理論上加入軸傾角與旋轉中心距離兩重要參數，計算交叉式雙旋翼的結果為1.375，與文獻的結果為1.388 [15]相當一致。
在無人直升機型方面，使用比例律(Scaling Law)將Kaman Aircraft’s K-1200直升機縮小成小尺寸無人直升機，預先估計的葉尖馬赫數(Tip Speed)為0.34，與SwissDrone’s SDO 50 V2無人機0.42[11]，相差約在20%；在後續設計上可用來先期計算，供後續設實驗測試參考。

The purpose of this study is to investigate the application of intermeshing rotors unmanned helicopters, including calculating the interference-induced power factor of intermeshing rotors, and inquiring design characteristics of intermeshing rotors. Three aspects are chosen to explore intermeshing rotors’ feature, i.e., interference-induced power factor, appearance, and application of unmanned helicopters. The design of the Kaman Aircraft's K-1200(K-MAX) and Kaman Aircraft’s HH-43B(Huskie) were applied to unmanned helicopters. The rotors shaft angle and the rotors center distances are important parameters. Due to structural factor, the unmanned helicopters can increase the rotors center distances, reduce the rotors shaft angle, and decrease the extra loss power . The interference-induced power factor plays an important role in helicopter efficiency calculation. It can be used to compare the energy lost by the rotor. Based on the coaxial rotors and tandem rotors momentum theory, Two parameters, the rotors shaft angle and the rotors center distances are added in this evaluation. The result of calculation is 1.375 which is very close to the result of the literature[15] is 1.38. In the unmanned helicopter application, the scaling law is used to scale down the Kaman Aircraft's K-1200 helicopter to a small-sized unmanned helicopter with a tip speed of 0.34, which is only 20% different from the unmanned helicopter SwissDrone’s SDO 50 V2 0.42[11]. These results will be very helpful to use in preliminary analysis before any experimental test.

[1]Watkinson, J. Art of the Helicopter, Butterworth-Heinemann, 2003.
[2]Coleman, C. P. “A Survey of Theoretical and Experimental Coaxial Rotor Aerodynamic Research,” National Aeronautics and Space Administration, Ames Research Center, 1997.
[3]Leishman, G. J. Principles of helicopter Aerodynamics with CD extra, Cambridge University Press, 2006.
[4]Dingeldein, R. C. “Wind-Tunnel Studies of the Performance of Multirotor Configurations,” NACA Technical Note 3246, 1954.
[5]Harris, F. D. “Twin Rotors Hover Performance,” Journal of the American Helicopter Society, Vol. 44, No. 1, p.34-37, 1999.
[6]Gessow, A., and Myers, G. C. Aerodynamics of the Helicopter, Frederick Ungar, 1952.
[7]Leishman, G. J., and Ananthan, S. “Aerodynamic Optimization of a Coaxial Proprotor,” Annual Forum Proceedings-American Helicopter Society, Vol. 62, No. 1, p.64, American Helicopter Society, INC, 2006.
[8]Mettler, B. Identification Modeling and Characteristics of Miniature Rotorcraft, Springer Science & Business Media, 2013.
[9]Kaman Aerospace Corporation, “K-1200 FAA Approved Rotorcraft Flight Manual,” Kaman Aerospace Corporation, Bloomfield Connecticut, USA, 2004.
[10]Wei, F. S., Moore, E., and Gates, A. “An Intermeshing Rotors Helicopter Design and Test,” 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, p.0564, 2015.
[11]Filippone, A. “Data and Performances of Selected Aircraft and Rotorcraft,” Progress in Aerospace Sciences, Vol. 36, No. 8, p.629-654, 2000.
[12]Saribay, Z., Wei, F. S., and Sahay, C. “Optimization of an Intermeshing Rotors Transmission System Design,” 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, p.2286, 2005.
[13]University of Maryland., “CalVert High-Speed V/STOL Personal Transport,” Department of Aerospace Engineering University of Maryland College Park, p.20740, 1999.
[14]Voigt, A. E., Dauer, J. C., and Knaak, F. “Measurement of Blade Deflection of an Unmanned Intermeshing Rotors Helicopter,” The 43rd European Rotorcraft Forum, September, 2017.
[15]Pflumm, T., Barth, A., Kondak, K., and Hajek, M. “Auslegung und Konstruktion eines Hauptrotorblattes für ein in extremen Flughöhen operierendes Drehflügel-UAV,” Deutsche Gesellschaft für Luft-und Raumfahrt-Lilienthal-Oberth eV, p.11, 2015.
[16]Voigt, A. E., Dauer, J. C., Krenik, A., and Dittrich, J. “Detection of Forward Flight Limitations of Unmanned Helicopters,” The 72nd Annual Forum of the American Helicopter Society, p.1-12, 2016.
[17]Yamakawa, M., Mitsunari, N., and Asao, S. “Numerical Simulation of Rotation of Intermeshing Rotors using Added and Eliminated Mesh Method,” Procedia Computer Science, 108, p.1883-1892, 2017.
[18]Harun-Or-Rashid, M, Song, J. B, Chae, S, Byun, Y. S, and Kang, B. S., “Unmanned Coaxial Rotor Helicopter Dynamics and System Parameter Estimation,” Journal of Mechanical Science and Technology, Vol. 28, No. 9, p.3797-3805, 2014.
[19]Frost, C., Tischler, M., and Bielefield, M. “Design and Test of Flight Control Laws for the Kaman Burro Unmanned Aerial Vehicle,” Atmospheric Flight Mechanics Conference, p.4205, 2000.
[20]SwissDrones Operating AG., “SDO 50 V2,” http://www.swissdrones.com/sdo-50/, 2014.
[21]CAD + Modelltechnik Jung., “Dragon,” http://www.cad-modelltechnik-jung.de/projekte/kamax.htm, 2009.