Experimental Measurement of The Phase-Sensitivity Function for A Circular Cylinder for Use in Predicting Wake Lock-In
Abstract
The goal of this research is to evaluate the feasibility of determining phase information from experimentally measured wake velocity data for use in phase-reduction analysis. The study is part of a combined effort with the University of California-Los Angeles to assess the validity of phase-reduction analysis on realistic fluid flows. The outcome from this effort is the validation of a general method to predict wake-synchronization conditions. Experimental data collection took place in the recirculating water tunnel at the Naval Postgraduate School, utilizing a custom-built testing fixture capable translational and rotational motion. Collected experimental data includes recorded time histories of wake velocity behind a circular cylinder before and after a small impulse that was introduced into the flow by perturbing a circular cylinder. Analysis of the data includes a curve-fit and Hilbert transform method in an attempt to accurately quantify the phase offset difference between the signals before and after impulse. The analysis showed some success in producing localized phase offset measurements, but still faces challenges due to variability in shedding frequency and the presence of irregular regions in the flow at Reynolds number 300. Alternate Reynolds numbers that were also explored show potentially more suitable conditions at lower Reynolds number flows with a lower shedding frequency.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2023
- Accession Number
- AD1213102
Entities
People
- Jacob M. Barberio
Organizations
- Naval Postgraduate School