Transverse displacement phase analysis on 2DOF FIV of rigid cylinders in tandem configurations

Modelling of wake-induced vibrations of tandem cylinders with a nonlinear wake-deficit oscillator

“…This aspect will be further elaborated in Section 4. However, both fixed-free and free-free tandem cylinders exhibit similar numerical WIV features with sustained amplitudes which are also shown by results of Assi (2005) and Pereira et al (2020). CFD results in the free-free tandem case with the same m* and d = 4 from Lin et al ( 2020) agree well with the numerical prediction, with the increasing response trend and comparable amplitudes for a limited range of 6  Ur  8.9…”

“…Recent CFD results ofLin et al (2020) with the same m* = 2.6,  = 0.007 and d = 4 are also compared in Fig.7a and b. Further, for 2 < Ur < 15, experimental A2/D results in free-free tandem cases ofAssi (2005) with m* = 1.92,  = 0.007, 2x10 3  Re  1.2x10 4 , d = 4, 5 and 5.6, and those (via a curve fitting) ofPereira et al (2020) with m* = 2.52 for the downstream cylinder and m* = 2.95 for upstream cylinder,  = 0.025, 3x10 3  Re  3x10 4 and d = 4 are presented in Fig.7b.…”

“…Overall, experimental and numerical responses reveal some amplitude discrepancies, and these are attributed to differences in the system parameters (m*, , Re, Ur, d) since wake oscillators have been calibrated in fixed-free tandem cases with results of Assi et al (2010). Of course, a re-tuning with results of Assi (2005) and Pereira et al ( 2020) can be performed, but this task will be infinite and restricted to a certain d, m*, , Re and Ur range apart from the fact that some of the two-cylinder properties may be dissimilar (e.g., Pereira et al (2020)). In Appendix, calibration and comparison with experimental results of Xu et al (2019) are presented, together with the model sensitivity to hydrodynamic coefficients (CL01, CL02, CD1, CD2, St1, St2).…”

Flexible longitudinal and transversal displacement sensors based on a composite of CI Disperse Orange 25 and carbon nanotubes

“…The fabrication and investigation of flexible, shockproof and vibration-free devices for measurement of longitudinal and transversal compressive displacement are important, firstly for practical applications, and secondly in the development of future technologies. [1][2][3][4][5] These devices perform a key role in the medical robotics industry. 6,7 Based on cost and performance matching, a systematic approach was developed for the selection of either longitudinal or transversal compressive sensors for medical applications (ie, right ventricular reading for cardiac surgery), 8 and the results indicated that the transversal displacement sensor gave the best response.…”