Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Statistical features and transition dynamics of coherent organizational states in turbulent pipe flow at moderate Reynolds numbers
Submission Author:
Robert Jäckel , RJ , Brazil
Co-Authors:
Robert Jäckel, Bruno Magacho, Bayode Owolabi, Luca Moriconi, Juliana Loureiro
Presenter: Robert Jäckel
doi://10.26678/ABCM.COBEM2023.COB2023-0590
Abstract
Recent advances in flow visualization techniques have provided a fascinating insight into the complex dynamics of evolving coherent structures. In turbulent pipe flow, coherent organizational states (COSs), labeled by discrete azimuthal wavenumber modes, are suspected to form the state space skeleton of the turbulent dynamics, around which the chaotic dynamics are organized. In this work, by means of stereoscopic particle image velocimetry and conditional averaging techniques, we are able to detect and visualize these COSs at moderate Reynolds number pipe flow (5300 < ReD < 24400) and study their statistical features and transition dynamics. We present, inter alia, their statistical weight contributions, streamwise organization, and recurrence time scales and show how these features evolve with the Reynolds number. The experimental results and statistical analysis uncover turbulent dynamics so far unexplored by providing a unique insight into turbulent pipe flow regarding its phenomenology vis-à-vis with statistical features which are highly relevant to better understand, predict, and model turbulence.
Keywords
Turbulence, Coherent Structures, Stereoscopic PIV
