Time series analysis based study of a mass-spring-like oscillation and detachment of a metal pendant droplet. (1st December 2016)

• Record Type: Journal Article
• Authors: Jeromen, Andrej; Govekar, Edvard
• Is Part Of: Mechanical systems and signal processing. Volume 80(2016)
• Page Start: 503
• Page End: 516
• Publication Date: 2016-12-01
• Subjects: Time series -- Time–frequency analysis -- Pendant droplet -- Mass-spring system -- Droplet detachment; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2016.04.038
• Languages: English
• ISSNs: 0888-3270

Abstract

Abstract: The subject of this study is the vertical mass-spring-like oscillation of a pendant droplet and its resonant detachment, which was experimentally observed in the process of laser droplet generation from a metal wire. The process was characterized by various time series, which were generated from a sequence of infrared intensity images of the process. Following a visual inspection of pendant droplet images and an analysis of a wavelet based time-frequency map of the droplet's vertical displacement time series, the pendant droplet's oscillation is described by a time-variable mass-spring system. Based on the characteristics of the time-frequency map, the resonant nature of the pendant droplet detachment was demonstrated. Additionally, an algebraic expression was formulated, which can be used to predict the detached droplet's diameter as a function of the laser pulse frequency. Highlights: Oscillating metal pendant droplet detachment was studied using time series analysis. A t–f map of the pendant droplet vertical displacement time series was calculated. Based on the t–f map, the pendant droplet was described as a mass-spring system. The t–f map showed the resonant nature of the pendant droplet detachment. The detached droplet diameter was predicted by an algebraic formula.