Design and Performance Tests of Cycloidal Propulsion Systems

Kim, Seung Jo; Yun, Chul Yong; Kim, Dae-Sung; Yoon, Youngmin; Park, Illkyung

doi:10.2514/6.2003-1786

Cited by 30 publications

(16 citation statements)

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“…Most of the previous experiments on cyclorotors have been performed at relatively larger scales [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. The key conclusions from these studies are summarized in [23].…”

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confidence: 65%

“…Moreover, because the blades are cyclically pitched once per revolution (1=rev), unsteady flow mechanisms may delay blade stall onset and so augment the net lift produced by the blades. Prior experiments have suggested that cyclorotors can reach efficiencies comparable to conventional rotor systems [8] and possibly higher values of maximum thrust. Furthermore, because the thrust vector of a cyclorotor can be almost instantaneously set to any direction perpendicular to the rotational axis, compared to a conventional rotor system a cyclorotor-based MAV may ultimately show better maneuverability and agility, which are particularly important attributes for constrained indoor flight operations.…”

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confidence: 99%

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Improving the Aerodynamic Performance of Micro-Air-Vehicle-Scale Cycloidal Rotor: An Experimental Approach

Benedict

Ramasamy

Chopra

2010

Journal of Aircraft

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Performance and flowfield measurements were conducted on a small-scale cyclorotor for application to a micro air vehicle. Detailed parametric studies were conducted to determine the effects of the number of blades, rotational speed, and blade pitching amplitude. The results showed that power loading and rotor efficiency increased when using more blades; this observation was found over a wide range of blade pitching amplitudes. The results also showed that operating the cyclorotor at higher pitching amplitudes resulted in improved performance, independently of the number of blades. A momentum balance performed using the flowfield measurements helped to quantify the vertical and sideward forces produced by the cyclorotor; these results correlated well with the force measurements made using load balance. Increasing the number of blades increased the inclination of the resultant thrust vector with respect to the vertical because of the increasing contribution of the sideward force. The profile drag coefficient of the blade sections computed using a momentum deficit approach correlated well with typical values at these low chord Reynolds numbers. Particle image velocimetry measurements made inside the cage of the cyclorotor showed that there are rotational flows that, when combined with the influence of the upper wake on the lower half of the rotor, explain the relatively low efficiency of the cyclorotor.

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confidence: 65%

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confidence: 99%

Improving the Aerodynamic Performance of Micro-Air-Vehicle-Scale Cycloidal Rotor: An Experimental Approach

Benedict

Ramasamy

Chopra

2010

Journal of Aircraft

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“…This feature is known as virtual camber effect and influences the attained thrust levels. 23 Thus, it may be stated that the blades are actually subjected to a curvilinear flow. The cascade effect in a cycloidal rotor analysis can initially be ignored due to the combined effect of low Reynolds number and low solidity values.…”

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confidence: 99%

Analytical modeling of a cyclorotor in hovering state

Leger

Páscoa

Xisto

2015

Proceedings of the Institution of Mechanical Engineers, Part G:

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In the paper it is proposed and described in detail a mathematical model that is able to assist in the design of cycloidal rotors. The method is formulated on a semi-empirical way including unsteady aerodynamic effects that are based on first principles. It is able to predict the overall generated thrust and the power required by the operation of the cycloidal rotor. The model also includes a kinematic package that can provide an instantaneous design and animation of the cycloidal rotor under different regimes of operation. For validation it was addressed three different rotor configurations where it was varied several rotor parameters, namely: pitch amplitude; pitching axis location; blade chord; airfoil thickness; phase angle of eccentricity. It was shown that the proposed model is able to provide a good estimation of thrust and power when compared with the experimental data from these different sources, showing that the semi-empirical approach could be applied in a more general way.

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“…The numerical simulation results also indicated that the cycloidal propeller can be compared with heavy-loaded helicopter rotor. Seong Hwang et al developed a quad-rotor cyclogyro and proved that the cycloidal propeller can provide enough thrust for hovering and forward flight (3)(4)(5)(6)(7)(8) . Benedict et al conducted extensive experimental and numerical simulations on the cycloidal propellers for MAVs (9,14) .…”

Section: Introductionmentioning

confidence: 99%

Investigation of unsteady aerodynamics effects in cycloidal rotor using RANS solver

Zhang

2016

Aeronaut. j.

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The cycloidal propeller for a Micro-Aerial Vehicle (MAV)-scale cyclogyro in hover was studied using a 2D Reynolds-averaged Navier-Stokes equations solver. The effects of the blade dynamic stall, parallel Blade Vortex Interaction (BVI), inflow variation and flow curvature were discussed, based on the results of numerical simulation. The results from the 2D Computational Fluid Dynamics simulation indicated that the blade of the cycloidal rotor is actually performing a pitching oscillation, if observed in a moving reference frame. The dynamic stall vortices shed from the upstream blade cause intense parallel BVI on the downstream blade. The interaction will induce upwash and downwash on the downstream blade. This changes the effective reduced frequency and actually delays the stall of the blade, which is beneficial to the thrust generation. There is also strong downwash in the rotor cage and it changes the inflow velocity experienced by the blade. The downwash and flow curvature can either be beneficial or harmful to the thrust generation. The combined effects of dynamic stall, parallel BVI, inflow variation and flow curvature cause large aerodynamic force peaks and ensure the cycloidal rotors work at very low rotation speeds with high thrust. This guarantees that the cycloidal rotors possess at least the same level of hover efficiency as screw propellers.

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Design and Performance Tests of Cycloidal Propulsion Systems

Cited by 30 publications

References 1 publication

Improving the Aerodynamic Performance of Micro-Air-Vehicle-Scale Cycloidal Rotor: An Experimental Approach

Improving the Aerodynamic Performance of Micro-Air-Vehicle-Scale Cycloidal Rotor: An Experimental Approach

Analytical modeling of a cyclorotor in hovering state

Investigation of unsteady aerodynamics effects in cycloidal rotor using RANS solver

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