Dynamic stall flutter analysis with uncertainties using Multi-Element Probabilistic Collocation

2007 ◽  
Author(s):  
G. J. Alex Loeven ◽  
S. Sarkar ◽  
J.A.S. Witteveen ◽  
Hester Bijl
Keyword(s):  
Dynamic Stall ◽  
Flutter Analysis ◽  
Stall Flutter ◽  
Probabilistic Collocation

Stall-Flutter Analysis

1973 ◽  
Vol 10 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Lars E. Ericsson ◽  
J. Peter Reding
Keyword(s):  
Flutter Analysis ◽  
Stall Flutter

Mechanisms for Wide-Chord Fan Blade Flutter

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Mehdi Vahdati ◽  
George Simpson ◽  
Mehmet Imregun
Keyword(s):  
Flow Separation ◽  
Pressure Wave ◽  
Geometric Features ◽  
The Third ◽  
Reflected Wave ◽  
Flutter Analysis ◽  
Parametric Studies ◽  
Blade Flutter ◽  
Stall Flutter ◽  
Fan Blade

This paper describes a detailed wide-chord fan blade flutter analysis with emphasis on flutter bite. The same fan was used with three different intakes of increasing complexity to explain flutter mechanisms. Two types of flutter, namely, stall and acoustic flutters, were identified. The first intake is a uniform cylinder, in which there are no acoustic reflections. Only the stall flutter, which is driven by flow separation, can exist in this case. The second intake, based on the first one, has a “bump” feature to reflect the fan’s forward pressure wave at a known location so that detailed parametric studies can be undertaken. The analysis revealed a mechanism for acoustic flutter, which is driven by the phase of the reflected wave. The third intake has the typical geometric features of a flight intake. The results indicate that flutter bite occurs when both stall and acoustic flutters happen at the same speed. It is also found that blade stiffening has no effect on aero-acoustic flutter.

scholarly journals Stall Flutter Control of a Smart Blade Section Undergoing Asymmetric Limit Oscillations

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Nailu Li ◽  
Mark J. Balas ◽  
Pourya Nikoueeyan ◽  
Hua Yang ◽  
Jonathan W. Naughton
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Control Algorithm ◽  
Dynamic Stall ◽  
Helicopter Rotor ◽  
Sensor Signal ◽  
Helicopter Rotor Blade ◽  
Blade Section ◽  
Control Capability ◽  
Stall Flutter

Stall flutter is an aeroelastic phenomenon resulting in unwanted oscillatory loads on the blade, such as wind turbine blade, helicopter rotor blade, and other flexible wing blades. Although the stall flutter and related aeroelastic control have been studied theoretically and experimentally, microtab control of asymmetric limit cycle oscillations (LCOs) in stall flutter cases has not been generally investigated. This paper presents an aeroservoelastic model to study the microtab control of the blade section undergoing moderate stall flutter and deep stall flutter separately. The effects of different dynamic stall conditions and the consequent asymmetric LCOs for both stall cases are simulated and analyzed. Then, for the design of the stall flutter controller, the potential sensor signal for the stall flutter, the microtab control capability of the stall flutter, and the control algorithm for the stall flutter are studied. The improvement and the superiority of the proposed adaptive stall flutter controller are shown by comparison with a simple stall flutter controller.

Stall flutter analysis

1972 ◽  
Author(s):  
L. ERICSSON ◽  
J. REDING
Keyword(s):  
Flutter Analysis ◽  
Stall Flutter

Dynamic Stall of an Airfoil With Leading Edge Bubble Separation Involving Time Dependent Re-Attachment

1978 ◽  
Author(s):  
H. Tokel ◽  
F. Sisto
Keyword(s):  
Leading Edge ◽  
Physical Problem ◽  
Dynamic Stall ◽  
Time Dependent ◽  
Harmonic Oscillations ◽  
Bubble Separation ◽  
Periodic Growth ◽  
Stall Flutter ◽  
The Mathematical Model ◽  
Dependent Point

The dynamic stall of an airfoil with leading edge bubble separation is analyzed. The stall flutter of turbomachine blading may involve periodic growth and collapse of such a bubble. The mathematical model representing the physical problem is presented. A flat plate undergoing harmonic oscillations with time-dependent point of re-attachment is studied for the perturbed aerodynamic reactions and applications to the stall flutter problem.

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