Optimum Parameters of a Rotating Cylindrical Shell for Feasibility of Performing Modal Testing by Fewer Circumferential Non-contact Sensors

Rotating cylindrical shells have a wide range of practical applications; however, they are prone to vibrations. Despite numerous theoretical studies on vibration characteristics of rotating cylindrical shells, experimental validation remains limited.  Using non-contact vibration sensors for an experimental study offers significant advantages, such as eliminating mass effects and avoiding complex wiring associated with attachment to rotating shells. However, achieving an adequate data acquisition frequency by non-contact sensors in modal analysis of rotating cylindrical shells necessitates deploying multiple sensors circumferentially, which makes it costly and complex. This difficulty could be mitigated by correct shell selection to enable experimental validation of theoretical studies. The primary objective of the present study is to determine with which dimensions and rotational velocities, an experimental result of vibration characteristics for a rotating cylindrical shell could be attained by fewer non-contact sensors, which could be interpreted as a first pace toward experimental validation of theoretical methods. To achieve this innovative goal, a parametric study was conducted using an accurate finite element method (FEM) in ANSYS to illustrate how rotational velocity and dimensions affect the required number of sensors. Using the results of the parametric study, optimum values of rotational speed and dimensional parameters have been determined in a way that the experimental vibration analysis could be accomplished with a minimum number of required circumferential non-contact sensors. In the case of the present study, the number of required circumferential sensors is reduced from about 200 for an unsuitable choice to 24 for the choice of the present paper.