Control of dynamic stall of helicopter rotor blades

Wang, Rong; Xia, Pinqi

doi:10.1007/s11431-012-5022-3

Cited by 4 publications

(4 citation statements)

References 8 publications

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“…In the dynamic inflow model, V 0 , V , and V can be obtained by solving the state-space equation (2). Thus the total induced velocity can be obtained by the summation of V 0 , V , and V It is pointed out that in the coupled model we recover the induced speed to a dimensional one.…”

Section: Aeroelastic Response Calculation Algorithmmentioning

confidence: 99%

“…In case of gust, it may cause the loss of trust force or the increase of deflection for rotors, which leads to the control instability or the blade failure. Hence, the dynamic load of rotors due to gust is considered as one of severe load cases in the design and certification processes of helicopter [2]. A helicopter is subjected to a wide variety of flight conditions with disparate objectives; these include efficient cruise and hover and high-performance maneuvering.…”

Section: Introductionmentioning

confidence: 99%

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Gust Response Analysis for Helicopter Rotors in the Hover and Forward Flights

Wang

Dai

Yang

2017

Shock and Vibration

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Dynamic load due to gust for helicopter rotors directly affects the structural stress and flight performance. In case of gust, it may cause the loss of trust force or the increase of deflection for rotors. In current work, an effective coupled aeroelastic model based on a medium-deflection beam theory and a nonlinear unsteady aerodynamic model in the time domain were constructed. Three types of gust in vertical direction were added in the model. The dynamic response and structural load for helicopter rotors under three types of gust were calculated, respectively. Results indicated that when rotors suffer a gust in hover at downward direction, the thrust force on rotor disk would decrease significantly when the gust amplitude increases, which should be paid attention in the design. Among the three gust types with the same gust strength, the maximum instantaneous shear force due to impulse shape gust is the largest. When the rotors suffer a gust in a forward flight, the shear force at the root of rotors would increase with the gust strength first but then it decreases. More attention should be paid to the decrease of thrust force and the increase of structural load in a forward flight.

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Section: Aeroelastic Response Calculation Algorithmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Gust Response Analysis for Helicopter Rotors in the Hover and Forward Flights

Wang

Dai

Yang

2017

Shock and Vibration

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“…Dynamic stall is a kind of intense unsteady and nonlinear delayed flow phenomenon caused by a large range of flow separation over the wings or blades when the angle of attack changes periodically or dramatically with time. [1] This phenomenon is commonly found in the retreating blades of helicopter, [2][3][4] fast pitch maneuvering fighters, [5] wind turbine blades, [6] and rotating surging compressors, [7] which leads to unsteady flutter and vibratory loads.…”

Section: Introductionmentioning

confidence: 99%

Dynamic stall control over an airfoil by NS-DBD actuation*

et al. 2020

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The wind tunnel test was conducted with an NACA 0012 airfoil to explore the flow control effects on airfoil dynamic stall by NS-DBD plasma actuation. Firstly, light and deep dynamic stall states were set, based on the static stall characteristics of airfoil at a Reynolds number of 5.8 × 105. Then, the flow control effect of NS-DBD on dynamic stall was studied and the influence law of three typical reduced frequencies (k = 0.05, k = 0.05, and k = 0.15) was examined at various dimensionless actuation frequencies (F + = 1, F + = 2, and F + = 3). For both light and deep dynamic stall states, NS-DBD had almost no effect on upstroke. However, the lift coefficients on downstroke were increased significantly and the flow control effect at F + = 1 is the best. The flow control effect of the light stall state is more obvious than that of deep stall state under the same actuation conditions. For the same stall state, with the reduced frequency increasing, the control effect became worse. Based on the in being principles of flow separation control by NS-DBD, the mechanism of dynamic stall control was discussed and the influence of reduced frequency on the dynamic flow control was analyzed. Different from the static airfoil flow separation control, the separated angle of leading-edge shear layer for the airfoil in dynamic stall state is larger and flow control with dynamic oscillation is more difficult. The separated angle is closely related to the effective angle of attack, so the effect of dynamic stall control is greatly dependent on the history of angles of attack.

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“…With the information extracted by the visual system, the following unmanned helicopters can ascertain the direction and distance of the leader, thereby providing measurement information for the control and management of UAV formation. Of the various types of UAVs, small-scale unmanned helicopter can serve as an excellent platform for studying vehicles with maneuverability and versatility as these can be seamlessly manipulated in manual mode and easily operated in automatic mode [9][10][11][12]. The aim of this study is to design an adaptive, robust and efficient method that can be applied to UAV formation.…”

Section: Introductionmentioning

confidence: 99%

Biologically adaptive robust mean shift algorithm with Cauchy predator-prey BBO and space variant resolution for unmanned helicopter formation

Wang

Duan

2014

Sci. China Inf. Sci.

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Visual tracking technology can provide measurement information for unmanned helicopter formation and thus, more attention is being paid to this research area. We propose a novel mean shift (MS) algorithm that is both adaptive and robust for unmanned helicopter formation and apply it to the leading unmanned helicopter tracking. The movement of an unmanned helicopter is very flexible and changeable, which makes the tracking there of more difficulty than for common targets. In creating an algorithm that can adapt to the acceleration of the unmanned helicopter and estimates both the scale and orientation of the movement changes, we combine the traditional MS with the bio-inspired Cauchy predator-prey biogeography-based optimization (CPPBBO) evolutionary algorithm, and also the space variant resolution (SVR) mechanism of the human visual system (MS-CPPBBO-SVR). To demonstrate the effectiveness and robustness of the proposed method and justify the importance of the CPPBBO algorithm and SVR mechanism at the same time, a series of comparative experiments were carried out. The experimental results of the proposed MS-CPPBBO-SVR method are compared with other competitive tracking methods, such as MS, MS with SVR (MS-SVR), MS-SVR with several other optimization algorithms, and the robust particle filter algorithm. The experimental results demonstrate that our proposed tracking approach, MS-CPPBBO-SVR, is more adaptive, robust and efficient in target tracking than the other methods.

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Control of dynamic stall of helicopter rotor blades

Cited by 4 publications

References 8 publications

Gust Response Analysis for Helicopter Rotors in the Hover and Forward Flights

Gust Response Analysis for Helicopter Rotors in the Hover and Forward Flights

Dynamic stall control over an airfoil by NS-DBD actuation*

Biologically adaptive robust mean shift algorithm with Cauchy predator-prey BBO and space variant resolution for unmanned helicopter formation

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