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Information × Registration Number 0212U000651, 0107U004102 , R & D reports Title Nonlinear oscillations of pipelines with flowing inhomogeneous fluid popup.stage_title Head Samoilenko Anatolii Mikhailovych, Registration Date 12-03-2012 Organization International mathemetical center of National academy of sciences of Ukraine popup.description2 The variational principles of mechanics with regard for the well-known nonlinear mechanisms are applied to the pipeline-fluid system, and a nonlinear dynamical model of behavior of a pipeline in a neighborhood of the critical velocities of the flow is developed. On the basis of the method of modal decomposition, this model is transformed into a nonlinear finite-dimensional model (a system of ordinary differential equations) for the amplitude parameters. The latter is reduced to the Cauchy form, which allows one to numerically study the transient modes in the system and to numerically realize the given algorithm. By some testing examples, the degree of reliability of the model as for the representation of main properties of a pipeline is studied; the control over the fulfillment of the laws of symmetry and the laws of conservation, including the energy conservation law, is realized; the cases, where the flow occurs with constant and variable velocities (fluctuating velocity, acceleration, and deceleration) and the pressure fluctuates, are analyzed; and the possibilities to use such modes for a decrease of the amplitude of oscillations in a neighborhood of the critical velocities are considered. The reliability of the results obtained is ensured by the correct statement of the problem on the basis of the variational approach, the control over the fulfillment of the laws of symmetry and the energy conservation law, and the comparison of the results obtained with the results of other authors. Product Description popup.authors Іващенко Борис Петрович Буцан Георгій Петрович Дегтяр Олександр Тимофійович Круподер Алевтина Василівна Кузнєцова Світлана Анатоліївна Кухтін Валерій Васильович Лимарченко Володимир Олегович Лимарченко Олег Степанович Митропольський Юрій Олексійович popup.nrat_date 2020-04-02 Close