Rotor Blade Stability in Turbulent Flows-Part II

Fujimori, Yoshinori; Ye, Lin; Ariaratnam, Samuel T.

doi:10.2514/3.61202

Cited by 23 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main study motivation is related to the preeminence of estimation errors in the blade structural properties and aeroelastic loads, as identified by the research community [10,11]. Nevertheless, the blade flutter problem has been mainly studied by neglecting the effect of flow turbulence, even though this condition has been investigated in other structures, such as longspan bridges [12,13,14,15,16,17] and rotorcrafts [18,19]. The probability of blade flutter is examined through an implementation of stochastic differential equations [20].…”

Section: Introduction and Study Objectivesmentioning

confidence: 99%

Higher-order moment stability of large wind turbine blades under stochastic perturbations

Caracoglia

2024

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The current trend in offshore wind energy is to design and install systems with larger swept areas that yield unprecedented efficiency. Long and slender blades are needed to achieve this objective. As a result of aerodynamic and structural tailoring, slender blades are particularly susceptible to various dynamic instability phenomena during standard operations. One of these phenomena is the bending-torsion flutter that may lead either to structural failure or system breakdown. The research author has been examining blade flutter under the influence of stochastic perturbations, which include both flow turbulence and aeroelastic load variability. A reduced-order Markov model has been used to describe the effects of the various random perturbations. Mean-square stability has been recently explored; results suggest that perturbations may negatively impact the flutter angular speed and increase the risk of failure. In this study the model is employed to investigate moment stability beyond mean squares, observing that dynamic instability involves nonlinear propagation of the perturbations and may exhibit amplitude dependency. Third-order instability is investigated and compared against previous numerical results. The NREL 5MW reference wind turbine blade is used as a benchmark example.

show abstract

Section: Introduction and Study Objectivesmentioning

confidence: 99%

Higher-order moment stability of large wind turbine blades under stochastic perturbations

Caracoglia

2024

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…One important example is the case of random flutter of helicopter rotor blades in turbulent flow [4,5]. Another important class of aeroelastic problems concerns bridges in turbulent wind (for instance [6,7]).…”

Section: Introductionmentioning

confidence: 99%

Bifurcation characteristics of a two-dimensional structurally non-linear airfoil in turbulent flow

Poirel

Price

2006

Nonlinear Dyn

View full text Add to dashboard Cite

The dynamics of a structurally non-linear two-dimensional airfoil in turbulent flow is investigated numerically using a Monte Carlo approach. Both the longitudinal and vertical components of turbulence, corresponding to parametric (multiplicative) and external (additive) excitation, respectively, are modelled. The properties of the airfoil are chosen such that the underlying non-excited, deterministic system exhibits binary flutter; the loss of stability of the equilibrium point due to flutter then leads to a limit cycle oscillation (LCO) via a supercritical Hopf bifurcation. For the random system, the results are examined in terms of the probability structure of the response and the largest Lyapunov exponent. The airfoil response is interpreted from the point of view of the concepts of D-and P-bifurcations, as defined in random bifurcation theory. It is found that the bifurcation is characterized by a change in shape of the response probability structure, while no discontinuity in the variation of the largest Lyapunov exponent with airspeed is observed. In this sense, the trivial bifurcation obtained for the D. Poirel ( )

show abstract

Stochastic averaging: An approximate method of solving random vibration problems

Roberts

Spanos

1986

International Journal of Non-Linear Mechanics

493

157

View full text Add to dashboard Cite

Rotor Blade Stability in Turbulent Flows-Part II

Cited by 23 publications

References 5 publications

Higher-order moment stability of large wind turbine blades under stochastic perturbations

Higher-order moment stability of large wind turbine blades under stochastic perturbations

Bifurcation characteristics of a two-dimensional structurally non-linear airfoil in turbulent flow

Stochastic averaging: An approximate method of solving random vibration problems

Contact Info

Product

Resources

About