Numerical Study of the Main Rotor Wake Structures and Induced Velocity Fields at the Tail Rotor Location When Flying Near the Ground
(*) Corresponding author
This paper considers the Mi-8 helicopter main rotor aerodynamics when flying near the infinite ground surface. The research is based on the free wake model developed by authors at Moscow Aviation Institute. The distance from the rotor's hub to the ground surface in the range of H = 6-16 m and the values of free stream (flight) velocity in the range of V = 0-15 m/s are considered. The results of the visualization for both rotor wake shapes and streamlines are obtained. The influence of the ground proximity on the rotor wake shape, including the formation of "supervortex" and "ground vortex" structures are analyzed. The induced velocity fields of the main rotor in the area of the tail rotor location for various azimuth positions relative to the main rotor axis are studied. The conclusion is made about the significant influence of the ground effect on the rotor wake structure and induced velocities field, including the area of the tail rotor location. Particularly, at slip flight with speed V = 10 m/s, when the distance to the ground surface H increases from 6 to 12 m, the value of the average induced velocity at the tail rotor plane is growing up to four times. The obtained data have allowed taking into account such effects of aerodynamic interference in the simplified mathematical model of the research flight simulator of JSC Helicopters Mil and Kamov.
Copyright © 2021 The Authors - Published by Praise Worthy Prize under the CC BY-NC-ND license.
J. G. Leishman, Principles of Helicopter Aerodynamics. (Cambridge University Press, 2000).
Yu. M. Ignatkin et al, Research Of Vortical Wake Structure For Main Rotor Of Helicopter On Low Flight Speeds, All-Russian Scientific-Technical Journal "Polyot", No. 3, 2018, pp. 52-59. (In Russian).
Y. Ignatkin et al, Modelling the helicopter rotor aerodynamics at forward flight with free wake model and URANS method. Aviation. 24, No. 4, 2020, pp. 149-156.
C. Phillips, Computational study of rotorcraft aerodynamics in ground effect and brownout. Ph.D. dissertation, University of Glasgow, UK, 2010.
T. Fletcher, R. E. Brown, Helicopter tail rotor thrust and main rotor wake coupling in crosswind flight, Journal of Aircraft, Vol. 47, 2010, pp. 2136-2148.
Yu. M. Ignatkin et al, Computational modeling of interference between helicopter main and tail rotors based on nonlinear blade vortex model. Russian Aeronautics, Vol. 59, 2016, pp. 44-50.
Yücekayali, Arda & Ortakaya, Yüksel. Viscous Vortex Particle Method Explored for Main Rotor-Tail Rotor Interaction, The 8th Asian/Australian Rotorcraft Forum, (2019).
M. Knight, R. A. Hefner, Analysis of Ground Effect on the Lifting Airscrew, NASA TN-835, (1941).
I. C. Cheeseman, W. E. Bennett, The Effect of the Ground on a Helicopter Rotor in Forward Flight, R & M 3021, Aeronautical Research Council, (1957).
J. Koo, T. Oka, Experimental Study on the Ground Effect of a Model Helicopter Rotor in Hovering, NASA TT-F-13938, (1971).
P. F. Sheridan, W. Wiesner, Aerodynamics of helicopter flight near the ground. The 33th annual forum of the American helicopter society, (1977).
J. Light, Tip vortex geometry of a hovering helicopter rotor in ground effect, Journal of the American Helicopter Society, Vol. 38, No. 2, 1993, pp. 34-42.
E. A. Borisov et al, Experimental research of influence of sites size restrictions on aerodynamic characteristics of the rotor, Civil Aviation High Technologies, No. 212, 2015, pp. 98-104. (In Russian).
T. Lee, J. G. Leishman, M. Ramasamy, Fluid dynamics of interacting blade tip vortices with a ground plane, Journal of The American Helicopter Society, Vol. 55, 2008, pp. 22005-2200516.
N. D. Nathan, R. B. Green, The flow around a model helicopter main rotor in ground effect. Exp Fluids, Vol. 52, 2012, pp. 151-166.
A. D. Griffiths, J. G. Leishman, A Study of Dual-Rotor Interference and Ground Effect Using a Free-Vortex Wake Model, The 58th Annual Forum and Technology Display of the American Helicopter Society, 2002, pp. 592-612.
J. Zhao, C. He, Physics - Based Modeling of Viscous Ground Effect for Rotorcraft Applications. The 70th annual forum of the American helicopter society, (1977).
A.A. Aparinov et al, Numerical modeling of helicopter main rotor behavior near a small-scale helideck by the vortex method. Russian Aeronautics, Vol. 60, 2017, pp. 500-507.
C. Pasquali et al, Numerical-experimental correlation of hovering rotor aerodynamics in ground effect, Aerospace Science and Technology, Volume 106, 2020.
B. M. Kutz et al, Numerical investigation of helicopter rotors in ground effect, The 30th AIAA Applied Aerodynamics Conference, (2012).
M. Sugiura et al, Validation of CFD Codes for the Helicopter Wake in Ground Effect, The 43th European Rotorcraft Forum, (2017).
N. Salini et al, An Evaluation of Ground Effect Modelling for Rotors in Hover. The 6th Asian/Australian Rotorcraft Forum, (2017).
Şahbaz, Mehmet & Sezer Uzol, Nilay & Kurtulus, Dilek, Numerical and Experimental Investigation of Rotor Aerodynamics In Ground Effect with Inclined Planes, The 8th Asian/Australian Rotorcraft Forum, (2019).
F. Rovere et al, CFD Analysis of a micro rotor in ground effect, The 45th European Rotorcraft Forum, (2019).
X. Wang et al, Research on Finite Ground Effect of a Rotor, The IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), (2019),
P. Silva et al, Simple multiple reference frame for high-order solution of hovering rotors with and without ground effect, Aerospace Science and Technology, Volume 111, 2021, 106518
R. E. Brown, G. R. Whitehouse, Modelling Rotor Wakes in Ground Effect. Journal of the American Helicopter Society, Vol. 49, 2004, pp. 238-249.
Yu. M. Ignatkin et al, A Nonlinear Blade Vortex Propeller Theory and Its Applications to Estimate Aerodynamic Characteristics for Helicopter Main Rotor and Anti-Torque Rotor, Vestnik MAI, Vol. 16, No. 5, 2009, pp. 24-31. (In Russian).
V. B. Zozulya, Y. P. Ivanov, Practical Aerodynamics of Mi-8 Helicopter, (Mashinostroenie, Moscow, 1977). (In Russian).
Marchetto, F., Benini, E., Numerical Simulation of Harmonic Pitching Supercritical Airfoils Equipped with Movable Gurney Flaps, (2019) International Review of Aerospace Engineering (IREASE), 12 (3), pp. 109-122.
Sugar-Gabor, O., Numerical Study of the Circular Cylinder in Supersonic Ground Effect Conditions, (2018) International Review of Aerospace Engineering (IREASE), 11 (1), pp. 15-26.
Sunil, A., Tide, P., Numerical Investigations on Suppression of Aeolian Vibrations on a Tall Chimney Using Helical Strakes, (2019) International Journal on Engineering Applications (IREA), 7 (5), pp. 152-159.
- There are currently no refbacks.
Please send any question about this web site to firstname.lastname@example.org
Copyright © 2005-2023 Praise Worthy Prize