November 23-25, 2025, Houston, Texas
Contributed Session

Flow Instability: Transition and Non Linearity

8:00 am – 10:36 am, Tuesday November 25 Session U23 George R. Brown Convention Center, 361CF
Chair:
Lukasz Klotz, Warsaw University of Technology
Topics:

Instability in a Spatially-Periodic Channel: Aspect-Ratio Dependence

10:10 am – 10:23 am
Presenter: Marc Antoni Guasch (Georgia Institute of Technology)
Authors: Brendan McCluskey (Princeton University), Alex Warhover (Georgia Institute of Technology), Parisa Mirbod (Department of Mechanical and Industrial Engineering, University of Illinois Chicago), Roman Grigoriev (Georgia Institute of Technology), Ari Glezer (Georgia Institute of Technology), Michael Schatz (Georgia Institute of Technology)

In channel flow with one wall textured with spanwise grooves distributed periodically in the streamwise direction, prior 2D simulations indicated a primary transition to stable waves similar to Tollmien-Schlichting modes at Reynolds numbers O(100), in contrast to transition in plane channel flow at Reynolds numbers O(1000). We present results from laboratory experiments and direct numerical simulations to compare instability onset measurements in large aspect-ratio channels with predictions from 2D and 3D simulations. Additionally, we investigate the onset of instability and the resulting flow behavior as a function of channel aspect-ratio.

Funding acknowledgement

Supported in part by the National Science Foundation under Grant Number 2230893.

PRESENTATIONS (12)