پیوندهای مفید
آمار
| تعداد نشریات | 7 |
| تعداد شماره‌ها | 399 |
| تعداد مقالات | 5,389 |
| تعداد مشاهده مقاله | 5,287,974 |
| تعداد دریافت فایل اصل مقاله | 4,882,721 |
Assessment of Fountain Flow Effects on Two Non-Overlap Tandem Rotors Performance | ||
| AUT Journal of Mechanical Engineering | ||
| مقاله 10، دوره 5، شماره 1، خرداد 2021، صفحه 173-190 اصل مقاله (1.47 M) | ||
| نوع مقاله: Research Article | ||
| شناسه دیجیتال (DOI): 10.22060/ajme.2020.17224.5850 | ||
| نویسندگان | ||
| Ali Mehrabi1؛ Ali R. Davari* 2 | ||
| 1Department of Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. | ||
| 2Department of MEchanical and Aerospace Eng., Schience and Research Branch, Azad University | ||
| چکیده | ||
| Very few issues are yet to be reported about the fountain flow beneath the tandem rotors configuration body in ground effect. In this paper, a series of tests have been performed using multipurpose test stand to study the fountain flow pattern of a sub-scale model of a generic tandem rotor helicopter in ground effect. Pressure and velocity measurements were performed by the pressure ports embedded longitudinally along a generic tandem rotor helicopter fuselage. The presence of a second rotor in tandem rotors configuration causes a fountain flow formation in the longitudinal center region below the helicopter and a semi-quiescent flow was there. The positive effects of this flow were detected such as increasing the sub-body pressure lifting force, the pressure distribution balance, and reinforcing the lift by the formation of the positive pressure gradient on sidewalls of the airframe. Tuft test observations confirmed the location of the fountain flow formation concluded from pressure and velocity measurements. The mentioned fountain flow aerodynamic effects must be taken into account in the tandem rotor helicopter flight controls trims, stability, and control augmentation system and lift force calculations. | ||
| کلیدواژه‌ها | ||
| Pressure distribution؛ Lift force؛ Non-overlapping tandem rotor؛ Fountain flow؛ Helicopter | ||
| مراجع | ||
|
[1] M. Silva, R. Riser, CH-47D tandem rotor outwash survey, in: AHS 67th Annual Forum, 2011. [2] USA. Transportation, Department of. 2010, Rotorcraft Flying Handbook. [3] G.J. Leishman, Principles of helicopter aerodynamics with CD extra, Cambridge university press, 2006. [4] J.R. Preston, S. Troutman, E. Keen, M. Silva, N. Whitman, M. Calvert, M. Cardamone, M. Moulton, S.W. Ferguson, Rotorwash Operational Footprint Modeling, Missile Research Development and Engineering Center Redstone Arsenal al …, 2014. [5] F.F. Felker, A review of tilt rotor download research, (1988). [6] F.F. Felker, J.S. Light, Aerodynamic interactions between a rotor and wing in hover, Journal of the American Helicopter Society, 33(2) (1988) 53-61. [7] M. MCVEIGH, The V-22 tilt-rotor large-scale rotor performance/wing download test and comparison with theory, Vertica, 10(3) (1986) 281-297. [8] D.R. Polak, W. Rehm, A.R. George, Effects of an image plane on the tiltrotor fountain flow, Journal of the American Helicopter Society, 45(2) (2000) 90-96. [9] M. Ramasamy, M. Potsdam, G.K. Yamauchi, Measurements to Understand the Flow Mechanisms Contributing to Tandem-Rotor Outwash, (2018). [10] V. Gupta, J.D. Baeder, Quad tilt rotor aerodynamics in helicopter mode, in: Annual Forum Proceedings-American Helicopter Society, American Helicopter Society, INC, 2005, pp. 416. [11] M. Ramasamy, J.G. Leishman, Interdependence of diffusion and straining of helicopter blade tip vortices, Journal of Aircraft, 41(5) (2004) 1014-1024. [12] B. Johnson, J.G. Leishman, A. Sydney, Investigation of Sediment Entrainment Using Dual‐Phase, High‐Speed Particle Image Velocimetry, Journal of the American Helicopter Society, 55(4) (2010) 42003-42003. [13] 24-ft Wind Tunnel Tests of Model Multi-Rotor Helicopters, RAE Report No. Aero 2207, 1947. [14] A. Halliday, D. Cox, Wind Tunnel Experiments on a Model of a Tandem Rotor Helicopter, HM Stationery Office, 1961. [15] J.-f. Tan, H.-w. Wang, Simulating unsteady aerodynamics of helicopter rotor with panel/viscous vortex particle method, Aerospace Science and Technology, 30(1) (2013) 255-268. [16] Y. You, D. Na, S.N. Jung, Improved rotor aeromechanics predictions using a fluid structure interaction approach, Aerospace Science and Technology, 73 (2018) 118-128. [17] A. Antoniadis, D. Drikakis, B. Zhong, G. Barakos, R. Steijl, M. Biava, L. Vigevano, A. Brocklehurst, O. Boelens, M. Dietz, Assessment of CFD methods against experimental flow measurements for helicopter flows, Aerospace Science and Technology, 19(1) (2012) 86-100. [18] G.M. Eberhart, Modeling of Ground Effect Benefits for Multi-Rotor Small Unmanned Aerial Systems at Hover, Ohio University, 2017. [19] H. Tadghighi, R.G. Rajagopalan, A user's manual for ROTTILT solver: Tiltrotor fountain flow field prediction, (1999). [20] L. Ye, Y. Zhang, S. Yang, X. Zhu, J. Dong, Numerical simulation of aerodynamic interaction for a tilt rotor aircraft in helicopter mode, Chinese Journal of aeronautics, 29(4) (2016) 843-854. [21] J.F. Tan, T.Y. Zhou, Y.M. Sun, G.N. Barakos, Numerical investigation of the aerodynamic interaction between a tiltrotor and a tandem rotor during shipboard operations, Aerospace Science and Technology, 87 (2019) 62-72. [22] F. Shahmiri, Experimental Investigation of the Hovering Performance of a Twin-Rotor Test Model, Journal of Aerospace Science and Technology (JAST), 10(2)(2013) 1-7. [23] A.M. Radhakrishnan, An experimental investigation of ground effect on a quad tilt rotor in hover and low speed forward flight, 2006. [24] Q. Wang, Q. Zhao, Rotor aerodynamic shape design for improving performance of an unmanned helicopter, Aerospace Science and Technology, 87 (2019) 478-487. [25] A.J. Wadcock, L.A. Ewing, E. Solis, M. Potsdam, G. Rajagopalan, Rotorcraft downwash flow field study to understand the aerodynamics of helicopter brownout, National Aeronautics and Space Administration Moffett Field Ca Ames Research …, 2008. [26] H. Tennekes, J.L. Lumley, J.L. Lumley, A first course in turbulence, MIT press, 1972. | ||
|
آمار تعداد مشاهده مقاله: 358 تعداد دریافت فایل اصل مقاله: 421 |
||