Effect of Passive flow Control of Bifurcation Phenomenon in Sudden Expansion channel

TL;DR

This study investigates how passive flow control via a centerline plate affects the bifurcation behavior in sudden expansion channels, showing increased critical Reynolds numbers and developing an empirical relation.

Contribution

It introduces a passive control method using a centerline plate and derives an empirical relation linking critical Reynolds number, plate length, and expansion ratio.

Findings

Critical Reynolds number increases with plate length.

Empirical relation accurately predicts bifurcation behavior.

Passive control delays symmetry-breaking bifurcation.

Abstract

In this article we describe, a numerical simulation has been performed for a channel flow with sudden expansion. Different geometric expansion ratios are considered in the current study such as 1:2, 1:3, and 1:4. The bifurcation phenomenon has been investigated for the baseline case and the critical Reynolds number is controlled using a passive modification in the channel. The geometry of sudden expansion channel is modified by introducing a two-dimensional plate along the center line of the channel at the expansion plane. This is one of the passive control techniques, which has been explored in the present study. The computations indicate that the critical Reynolds number of the symmetry-breaking bifurcation increases as the length of the plate increases. An empirical relation has been developed amongst the critical Reynolds number, length of control plates and expansion ratio (h/H). The critical Reynolds number predicted by the empirical relation for different plate lengths are in good agreement with computational results.