Topic
Critical speed
About: Critical speed is a research topic. Over the lifetime, 2764 publications have been published within this topic receiving 31365 citations.
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TL;DR: In this article, a program named Dynrot was used to make dynamic analysis and the evaluation of the results and how the software was used are presented in the study, a gas turbine rotor with certain geometrical and mechanical properties is modeled and its dynamic analysis was made by Dynrot program.
57 citations
TL;DR: In this paper, a cantilever pipe of about 5m length was partly submerged in water and the free open end of the pipe was in the water, whereas the fixed end was above the waterline.
57 citations
TL;DR: The transient response of the system with and without nonlinear feedback is obtained to show the effectiveness of non linear feedback.
Abstract: Nonlinear oscillations in magnetic bearings caused by gyroscopic effects at high speeds are analyzed. First a nonlinear model for the magnetic bearing is set in state-variable form using airgap flux, gap displacement, and velocity as state variables. The system, which is unstable in nature, is stabilized locally around the equilibrium point of zero speed using an optimal robust servo controller. It is shown that as the speed changes the system undergoes Hopf bifurcation to periodic solutions around some critical speed. The periodic solutions are shown to be unstable, so the methods of nonlinear bifurcation control are used to stabilize them. An easily implemented nonlinear feedback control of quadratic order is derived to control the Hopf bifurcation occurring in the system. The transient response of the system with and without nonlinear feedback is obtained to show the effectiveness of nonlinear feedback. >
57 citations
TL;DR: In this paper, the additional slope is used to consider the crack breathing, and is expressed explicitly in the equation of motion as one of the inputs to produce the bending moment at the crack position.
56 citations
TL;DR: In this paper, the nonlinear dynamics of a transverse galloping blunt body oscillator with respect to its geometric shape and size was analyzed using an approximation for the lateral aerodynamic force that is a polynomial function of the angle of attack.
56 citations