Eur. Phys. J. Plus (2021) 136: 953
https://doi.org/10.1140/epjp/s13360-021-01947-2

Regular Article

Flow features of a new fluidic oscillator using time-resolved PIV measurement and 3D numerical simulation

¹ Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
² School of Mechanical Engineering, Pusan National University, Busan, Republic of Korea
³ Department of Naval Architecture and Ocean Engineering, Pusan National University, Busan, Republic of Korea

^a m.nili@cc.iut.ac.ir
^e kckim@pusan.ac.kr

Received: 25 June 2021
Accepted: 6 September 2021
Published online: 17 September 2021

Abstract

The current study measures the instantaneous velocity field inside and outside a new designed fluidic oscillator using planar time-resolved PIV technique on its symmetry plane in a water tank. The instantaneous velocity field showed that the interaction of four vortices with the jet was the main reason of jet oscillation inside the main chamber. Three-dimensional transient numerical solutions were also carried out using Ansys-Fluent 2020R2 software. Four turbulence models (k-ε, k-ε RNG, k-ω, and k-ω SST) were used for these numerical solutions, which their results were then compared with the PIV results, qualitatively and quantitatively. The comparison showed that the k-ε and k-ω SST models were better for simulating the flow of the new oscillator. However, both models over-predicted the jet spreading angle and oscillation frequency compared to the PIV results. A similar PIV measurement was accomplished outside the conventional oscillator to compare the time-averaged velocity fields of the new and conventional oscillators. The comparison showed that the amplitude and frequency of the new oscillator were, respectively, lower and higher than those of the conventional one. The time-averaged velocity and momentum flux outside the new oscillator was significantly higher than for the conventional one.