کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4976864 1451837 2018 22 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nonlinear state-space modelling of the kinematics of an oscillating circular cylinder in a fluid flow
ترجمه فارسی عنوان
مدل سازی غیرخطی حالت-فضا از سینماتیک یک سیلندر دایره ای نوسانی در یک جریان مایع
کلمات کلیدی
ارتعاش ناشی از باد نوسان سیلندر اجباری، شناسایی سیستم، پردازش سیگنال، مدل سازی غیر خطی سیاه و سفید، مدل حالت-فضا غیر خطی چندجمله ای،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی کامپیوتر پردازش سیگنال
چکیده انگلیسی


- System identification of a nonlinear model of an oscillating cylinder in a fluid.
- Data from CFD are used to identify a discrete polynomial nonlinear state-space model.
- The model is validated over a wide range of oscillating frequencies and amplitudes.

The flow-induced vibration of bluff bodies is an important problem of many marine, civil, or mechanical engineers. In the design phase of such structures, it is vital to obtain good predictions of the fluid forces acting on the structure. Current methods rely on computational fluid dynamic simulations (CFD), with a too high computational cost to be effectively used in the design phase or for control applications. Alternative methods use heuristic mathematical models of the fluid forces, but these lack the accuracy (they often assume the system to be linear) or flexibility to be useful over a wide operating range.In this work we show that it is possible to build an accurate, flexible and low-computational-cost mathematical model using nonlinear system identification techniques. This model is data driven: it is trained over a user-defined region of interest using data obtained from experiments or simulations, or both. Here we use a Van der Pol oscillator as well as CFD simulations of an oscillating circular cylinder to generate the training data. Then a discrete-time polynomial nonlinear state-space model is fit to the data. This model relates the oscillation of the cylinder to the force that the fluid exerts on the cylinder. The model is finally validated over a wide range of oscillation frequencies and amplitudes, both inside and outside the so-called lock-in region. We show that forces simulated by the model are in good agreement with the data obtained from CFD.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Mechanical Systems and Signal Processing - Volume 98, 1 January 2018, Pages 209-230
نویسندگان
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