Design of a New Unmanned Aerial Vehicle Cyclocopter

Min

et al. 2016

Journal of Aircraft

Self Cite

A cyclocopter is a vertical takeoff and landing aircraft that has cycloidal blade systems that consist of several blades rotating about a horizontal axis. The cycloidal blade system allows changes in direction and magnitude of the generated thrust. This paper describes the design and experimental studies of a 110 kg cyclocopter having two cycloidal blade system rotors and one tail propeller rotor powered by a 300-cm 3 -class rotary engine. The tail rotor generates pitching motion and compensates for the torque generated by the front two rotors. The upward thrust direction of the tail rotor provides 10% of the lifting force. The design thrust of the cycloidal blade system rotor is estimated in analytical and numerical analyses. An accurate analytical aerodynamic model is developed. The analytically estimated results have a trend similar to that of computational fluid dynamics analysis. Both analysis results match well with the results of a ground test. The onboard flight control computer system has two embedded processors, and a proportional-integral-derivative algorithm is used as the flight control scheme. The gains of the proportional-integral-derivative algorithm are adjusted during tethered flight tests. Finally, the developed cyclocopter demonstrates hovering and maneuvering flight in a tethered test. Nomenclature C Lα= lift curve slope l = main shaft length p 0 = pressure at the free end of the main shaft T u , T d = thrust on upstream and downstream sides, respectively U R = resultant velocity U T , U P = tangential and perpendicular components of velocity, respectively λ u , λ d = inflow ratio on upstream and downstream sides, respectively ψ u = azimuth angles on the upstream side ψ d = azimuth angles on the downstream side Ω = rotational speed of main shaft Ω 0 = whirling speed of the shaft with zero external pressure [Eq. (24)]

Section: Cfd Analysissupporting

confidence: 66%

“…The following equations [Eqs. (1)(2)(3)(4)(5)(6)] are modified from Yun et al's multiple streamtube equations [12]. The element thrusts on the upstream and downstream sides are…”

Section: A Streamtube Contraction Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Design, Analysis, and Experimental Investigation of a Cyclocopter with Two Rotors

Min

et al. 2016

Journal of Aircraft

Self Cite

“…[18][19][20][21]. A single rotor experiment was conducted to verify the potential of CBS for a VTOL air vehicle.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of a Quadrotor Cyclocopter

Kim¹,

Min²,

Lee³

et al. 2015

J Am Helicopter Soc

Self Cite

Recently, a quadrotor cyclocopter that weighs approximately 13 kg was designed and manufactured. Many components were improved from earlier cyclocopters, including the mainframe, power unit, transmission, hub-spoke structure, and rotor control mechanism. Ground and tethered flight tests were conducted prior to the free flight test of the vehicle. The test bed included load cells, a tachometer, and a digital power meter, which measured vertical and horizontal forces, electric consumed power, and rotational speed. The ground tests measured rotor performance and differences between single and multiple rotor cases, while demonstrating a capability of the quadrotor cyclocopter to perform free flight. Gains of a simple proportional-integral-derivative (PID) algorithm embedded in the flight control system, installed on the cyclocopter, were adjusted during the tethered flight tests. The quadrotor cyclocopter eventually fulfilled a stable hover and low-speed level flight and showed great potential for an expanded maneuvering capability.

“…Prior experiments have suggested that cyclorotors can reach efficiencies comparable to conventional rotor systems (Ref. 9) and may also produce relatively 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, a cyclorotor-based MAV may ultimately show better maneuverability and agility as compared to a MAV powered by a conventional rotor system, which are particularly important attributes for constrained indoor flight operations.…”

Section: Introductionmentioning

confidence: 99%

Experimental Optimization of MAV-Scale Cycloidal Rotor Performance

Benedict¹,

Jarugumilli²,

Chopra³

2011

j am helicopter soc

This paper describes the systematic experimental studies performed to optimize the performance of a microscale cycloidal rotor. Parametric studies were conducted to determine the dependence of cycloidal rotor performance on rotational speed, blade pitching amplitude (symmetric and asymmetric pitching), blade airfoil profile, number of blades (at constant solidity), and the location of pitching axis. Higher blade pitch angles were found to improve the power loading (thrust/power) of the cycloidal rotor. Asymmetric pitching with a higher pitch angle at the top of the blade trajectory than at the bottom produced better power loading. The chordwise optimum pitching axis location was approximately 25-35% of the blade chord. For a constant solidity, the rotor with fewer number of blades produced higher thrust and the two-bladed rotor had the best power loading. A hover-capable quad-cyclocopter was designed and built to demonstrate the flightworthiness of the cycloidal rotor concept.