Topic
Critical speed
About: Critical speed is a research topic. Over the lifetime, 2764 publications have been published within this topic receiving 31365 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: Lee et al. as mentioned in this paper demonstrated that a nonlinear energy sink can improve the stability of an aeroelastic system by attaching it to a rigid airfoil, which was supported in a low-speed wind tunnel by nonlinear springs separately adjustable in heave and pitch.
Abstract: This paper presents experimental results corroborating the analysis developed in the companion paper, Part 1 (Lee, Y., Vakakis, A., Bergman, L., McFarland, M., and Kerschen G., "Suppression Aeroelastic Instability Using Broadband Passive Targeted Energy Transfers, Part 1: Theory," AIAA Journal, Vol. 45, No. 3,2007, pp. 693-711), and demonstrates that a nonlinear energy sink can improve the stability of an aeroelastic system. The nonlinear energy sink was, in this case, attached to the heave (plunge) degree of freedom of a rigid airfoil which was supported in a low-speed wind tunnel by nonlinear springs separately adjustable in heave and pitch. This airfoil was found to exhibit a limit cycle oscillation at flow speeds above the critical ("flutter") speed of 9.5 m/s, easily triggered by an initial heave displacement. After attachment of a single degree of freedom, essentially nonlinear energy sink to the wing, the combined system exhibited improved dynamic response as measured by the reduction or elimination of limit cycle oscillation at flow speeds significantly greater than the wing's critical speed. The design, application, and performance of the nonlinear energy sink are described herein, and the results obtained are compared to analytical predictions. The physics of the interaction of the sink with the wing is examined in detail.
145 citations
TL;DR: In this article, two new breathing functions were identified to represent the actual breathing effect on the cracked element stiffness matrix, which were then used in formulating the time-varying finite element stiffness matrices of a cracked element.
144 citations
TL;DR: In this paper, the dynamic behaviour of a section of whirling drill collars is analyzed in terms of rotor dynamics, with account taken of the nonlinear influences caused by drilling fluid, stabilizer clearance and stabilizer friction.
144 citations
TL;DR: In this paper, a theoretical model for train-induced ground vibration propagation is presented based on the track and a layered ground and the results of the responses of the ground and track to a moving harmonic or quasi-static load on the rails are given.
144 citations
Journal Article•
TL;DR: In this paper, a geometrically exact structural analysis and finite-state unsteady aerodynamics with stall is presented for limit-cycle oscillations in high-aspect-ratio wings caused by structural and aerodynamic nonlinearities.
143 citations