{"title":"Damping Oscillations of a Cylinder with a Coaxial Disk and a Stabilizer","authors":"D. V. Kaufman, A. N. Ryabinin","doi":"10.1134/s1063454124010060","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Damped rotational oscillations of a cylinder equipped with a coaxial disk in the head part and a stabilizer in the tail part are studied. The elongation of the cylinder (the ratio of its length to diameter) is nine. The cylinder is mounted in the test section of the low-velocity wind tunnel with a wire suspension containing steel springs. In the equilibrium position, the cylinder axis is horizontal and parallel to the velocity vector of the incoming flow. A semiconductor strain gauge is attached to one of the suspension springs, which measures the time dependence of spring tension during oscillations. The output voltage of the strain gauge is sent to a PC oscilloscope, the digital signal of which is transmitted to the computer. After calibration of the device, the frequency and amplitude of damped rotational oscillations around the horizontal axis passing through the center of the cylinder and perpendicular to the velocity vector of the incoming flow were determined. The air flow enhances the rate of the damping of rotational oscillations of the cylinder. The air flow effect is described by analogues of rotational derivatives, which, in the case of bluff bodies, depend on the amplitude of the oscillations of the inclination angle of the body and on the amplitude of the angular velocity. A simple model of the effect of a stabilizer on rotational derivatives is proposed.</p>","PeriodicalId":43418,"journal":{"name":"Vestnik St Petersburg University-Mathematics","volume":"2014 1","pages":""},"PeriodicalIF":0.4000,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Vestnik St Petersburg University-Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1134/s1063454124010060","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Damped rotational oscillations of a cylinder equipped with a coaxial disk in the head part and a stabilizer in the tail part are studied. The elongation of the cylinder (the ratio of its length to diameter) is nine. The cylinder is mounted in the test section of the low-velocity wind tunnel with a wire suspension containing steel springs. In the equilibrium position, the cylinder axis is horizontal and parallel to the velocity vector of the incoming flow. A semiconductor strain gauge is attached to one of the suspension springs, which measures the time dependence of spring tension during oscillations. The output voltage of the strain gauge is sent to a PC oscilloscope, the digital signal of which is transmitted to the computer. After calibration of the device, the frequency and amplitude of damped rotational oscillations around the horizontal axis passing through the center of the cylinder and perpendicular to the velocity vector of the incoming flow were determined. The air flow enhances the rate of the damping of rotational oscillations of the cylinder. The air flow effect is described by analogues of rotational derivatives, which, in the case of bluff bodies, depend on the amplitude of the oscillations of the inclination angle of the body and on the amplitude of the angular velocity. A simple model of the effect of a stabilizer on rotational derivatives is proposed.
摘要 研究了头部装有同轴圆盘、尾部装有稳定器的圆柱体的阻尼旋转振动。气缸的伸长率(长度与直径之比)为 9。气缸安装在低速风洞的试验段中,悬挂架上装有钢丝弹簧。在平衡位置,圆柱体轴线水平,平行于流入气流的速度矢量。一个半导体应变计安装在其中一个悬挂弹簧上,用于测量摆动过程中弹簧张力的时间相关性。应变计的输出电压被发送到 PC 示波器,示波器的数字信号被传输到计算机。校准设备后,确定了围绕穿过气缸中心、垂直于流入气流速度矢量的水平轴的阻尼旋转振荡的频率和振幅。气流提高了气缸旋转振荡的阻尼率。气流效应由旋转导数的类似物来描述,在崖体的情况下,旋转导数取决于崖体倾角振荡的振幅和角速度的振幅。本文提出了一个稳定器对旋转导数影响的简单模型。
期刊介绍:
Vestnik St. Petersburg University, Mathematics is a journal that publishes original contributions in all areas of fundamental and applied mathematics. It is the prime outlet for the findings of scientists from the Faculty of Mathematics and Mechanics of St. Petersburg State University. Articles of the journal cover the major areas of fundamental and applied mathematics. The following are the main subject headings: Mathematical Analysis; Higher Algebra and Numbers Theory; Higher Geometry; Differential Equations; Mathematical Physics; Computational Mathematics and Numerical Analysis; Statistical Simulation; Theoretical Cybernetics; Game Theory; Operations Research; Theory of Probability and Mathematical Statistics, and Mathematical Problems of Mechanics and Astronomy.