کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7175754 | 1466567 | 2018 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Flow-induced vibrations of two mechanically coupled pivoted circular cylinders: Characteristics of vibration
ترجمه فارسی عنوان
لرزش ناشی از جریان از دو سیلندر دایره ای چرخشی مجهز به مکانیکی: ویژگی ارتعاش
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
سایر رشته های مهندسی
مهندسی مکانیک
چکیده انگلیسی
This paper presents the results of an experimental investigation on the vibration mechanisms of two connected circular cylinders that are free to rotate around a pivot in different arrangements including both cylinders on the downstream, both on the upstream and a cylinder on each side of the pivot point. The Reynolds number is varied during the test to find the maximum possible displacement amplitude for each configuration. Four main mechanisms of vibration are identified. The cylinders experience galloping if both located on the upstream of the pivot and the gap between them is zero. Vortex excitation (VE) is observed in two configurations and referred to as VEfSt and VEfN. VEfSt occurs when both cylinders are located on the downstream of the pivot while the gap is zero. The frequency responses lock into the Strouhal frequency in this case. VEfN occurs when the center of gravity (cg) is on the pivot and the gap ratio (G=gapâcylinderdiameter) between the cylinders is GÂ >Â 3.9. In this case, the frequency response locks into the natural frequency of the system. If one cylinder is located on the center of the rotation and the other cylinder is on the downstream, wake-induced vibration (WIV) takes place. While for GÂ <Â 1.4 the response is a typical wake galloping, for GÂ >Â 1.4 two vibration modes are recognizable as 'combined vortex resonance and galloping'. For all configurations with G> 0, gap-switching-induced vibration (GSIV) is observed especially for 1.9Â <Â GÂ <Â 2.4. However, GSIV is the dominant mechanism of vibration if cg is on the pivot point. In cases where cg is not close to the pivot, the drag force may enhance the vibration if the Reynolds number is not large enough to suppress the motion.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Fluids and Structures - Volume 80, July 2018, Pages 165-178
Journal: Journal of Fluids and Structures - Volume 80, July 2018, Pages 165-178
نویسندگان
Hamid Arionfard, Yoshiki Nishi,