Control of the flow behind a backward-facing step by visual feedback

TL;DR

This paper demonstrates real-time visual feedback control of flow behind a backward-facing step using velocity fields and novel inputs like swirling strength, enabling automatic tuning of control parameters.

Contribution

Introduces a visual feedback approach using real-time velocity fields and swirling strength for flow control, expanding beyond traditional recirculation area methods.

Findings

Flow can be controlled using visual feedback from multiple vantage points.

Swirling strength effectively used as input for PID control.

Real-time velocity field computation enables adaptive flow management.

Abstract

The separated flow downstream a backward-facing step is controlled using visual information for feedback. This is done when looking at the flow from two vantage points. Flow velocity fields are computed in real-time and used to yield inputs to a control loop. This approach to flow control is shown to be able to control the detached flow in the same way as has been done before by using the area of the recirculation region downstream the step as input for a gradient descent optimization scheme. Visual feedback using real-time computations of 2D velocity fields also allows for novel inputs to the feedback scheme. As a proof of concept, the spatially averaged value of the swirling strength is successfully used as input for an automatically tuned PID controller.