Experimental data of the influence of the number of rows of a tube bank on the FIV

Data result from careful measurements with accelerometers in an aerodynamic channel to study the phenomenon of fluid-elastic instability in a square arrangement rows of cylinders and tube bank with all fixed tubes and with one cylinder free to vibrate. The Reynolds number for the tested cases ranged between 11850 and 64104, based on one cylinder diameter and the kinematic viscosity at the environmental conditions of the laboratory. The gap velocity is obtained applying mass conservation considering the reference velocity and area upstream the test section and the free area with the row of cylinders. The test section is assembled with smooth cylinders with 25mm diameter and a p/D-ratio of 1.26. One of the cylinders has one degree of freedom. It is free-to-vibrate in the transversal direction, being attached to two blades that allow the variation of length, to change the stiffness. The positions of the cylinders were numbered and the cylinder free to vibrate was assembled in positions 3 (central cylinder of first row), 8 (central cylinder of second row), 13 (central cylinder of Third row), or 18 (central cylinder of fourth row). The assembly of the cylinder free to vibrate is the same used in Neumeister et al. (2021, a-b). A total of 27 cases were conducted, starting with a single cylinder (reference case), than rows of cylinders, changing the number of rows, the stiffness, and mass ratio. The tested cases present the nomenclature indicating if the case is a single-cylinder (SC), if it is one row (1R), two rows (2R), three rows (3R), four rows (4R) or five rows (5R), the position of the cylinder free to vibrate (P3, P8, P13, P18) and the first natural frequency. The acceleration of the cylinder free to vibrate is the monitored variable. The measurements were executed with accelerometers ADXL 335 with an acquisition frequency of 1 kHz with an anti-aliasing low pass filter at 0.3 kHz. Data acquisition was executed employing an A/D board 16bits NI USB-9162. The acceleration results are presented through the values obtained during the data acquisition for each case tested. Uncertainty values are about 7 % for the acceleration of the cylinder; for the velocity, between 7 and 8 %; for the frequency, uncertainty is about 9 %, leading to a value of 10.5 % for the uncertainty of the reduced velocity. REFERENCES Neumeister, R.F., Petry, A.P., Möller, 2021-a, Analysis of the coherence between FIV acceleration and flow velocity in a square array tube bank with P/D = 1.26. Nuclear Engineering and Design, v. 373, p. 111016, DOI: 10.1016/j.nucengdes.2020.111016 Neumeister, R.F., Petry, A.P., Möller, 2021-b, Experimental Flow-Induced Vibration Analysis of the Crossflow Past a Single Cylinder and Pairs of Cylinders in Tandem and Side-By-Side. Journal of Pressure Vessel Technology-Transactions of the ASME, v. 143, p. 031402, 2021, DOI: 10.1115/1.4048101本数据集来自气动通道内加速度计的精细测量结果，用于研究方形排列圆柱管束（tube bank）的流体弹性失稳（fluid-elastic instability）现象，试验包含全固定圆柱管束以及带有1个可自由振动圆柱的管束两类工况。 本次试验的雷诺数（Reynolds number）范围为11850至64104，该雷诺数以圆柱直径为特征长度，基于实验室环境条件下的运动粘度（kinematic viscosity）计算得到。间隙流速通过质量守恒（mass conservation）定律求得，结合试验段上游的参考流速与过流面积，以及圆柱列的有效通流面积计算得到。 试验段采用直径25mm的光滑圆柱组装而成，圆柱间距与直径比（p/D-ratio）为1.26。其中1个圆柱拥有单自由度（one degree of freedom），可沿横向自由振动，该圆柱与两根可调节长度的支撑叶片相连，以此调整系统刚度。所有圆柱均进行了编号，可振动圆柱被安装于第1排中心位置（编号3）、第2排中心位置（编号8）、第3排中心位置（编号13）及第4排中心位置（编号18）。可振动圆柱的组装方案与Neumeister等人（2021a、2021b）的研究一致。 本次试验共开展27组工况，初始工况为单圆柱（参考工况），后续依次调整圆柱排数、系统刚度与质量比。试验工况采用统一命名规则，用以标识工况类型：单圆柱（Single Cylinder，SC）、1排圆柱（1R）、2排圆柱（2R）、3排圆柱（3R）、4排圆柱（4R）及5排圆柱（5R），同时标注可振动圆柱的安装位置与一阶固有频率。 本次试验的监测变量为可振动圆柱的加速度，测量采用ADXL 335型加速度计（accelerometers），采集频率为1kHz，并配置0.3kHz的抗混叠低通滤波器（anti-aliasing low pass filter）。 数据采集系统采用16位模数转换板（A/D board）NI USB-9162。所有测试工况的加速度采集结果均以原始采集数据形式呈现。 各测量参数的不确定度如下：圆柱加速度不确定度约为7%，流速不确定度介于7%至8%之间，频率不确定度约为9%，由此推导得到折算速度（reduced velocity）的不确定度为10.5%。 参考文献 Neumeister, R.F., Petry, A.P., Möller, 2021-a, 《P/D=1.26的方形排列管束内流致振动加速度与流场流速相干性分析》，《核工程与设计》，第373卷，第111016页，DOI: 10.1016/j.nucengdes.2020.111016 Neumeister, R.F., Petry, A.P., Möller, 2021-b, 《横掠单圆柱及串列、并列双圆柱的流致振动实验分析》，《压力容器技术-ASME汇刊》，第143卷，第031402页，2021年，DOI: 10.1115/1.4048101