# Coanda Flow Characterization on Base Bleed Configurations Using Global Stability Analysis

## TL;DR

This paper uses global stability analysis and adjoint methods to understand and optimize base bleed flow configurations, aiming to improve aerodynamic performance and thermal protection in turbines.

## Contribution

It introduces a comprehensive stability and sensitivity analysis framework for base bleed flows, enhancing understanding of flow interactions and control strategies in turbine applications.

## Key findings

- Identified flow regions most receptive to control methods
- Revealed physical mechanisms driving pressure bifurcations
- Provided insights for optimizing base bleed configurations

## Abstract

Base pressure control is often employed on drag reduction design, but the interaction of the jet with the base region flow topology can generate undesired or uncontrolled flow configurations. The ejected flow can drive pressure bifurcations at the trailing edge, that without a correct optimization can affect the aerodynamic performance of the system. The purpose of this work is to fully understand the physical mechanisms related with the use of injected base bleed employing global stability analysis and adjoint methodologies. Moreover, the results of the sensitivity analysis are used to identify the regions more receptive to passive and active flow control methodologies. This work has a particular relevance in turbine research, where coolant flow is ejected at the trailing edge to ensure an adequate thermal protection of the blade and the downstream turbine stages.