Taming Combustion Instabilities by Design Principles

Both, the energy and aviation sector rely on gas turbines, a combustion system continuously optimized since its invention during World War II. They constitute a main pillar for tomorrows energy and aviation mix to tackle climate change.

However, fuel flexibility is stretched to its limits for conventional combustor designs: combustion instabilities hinder a new generation of safe and low-emission gas turbines. This calls for disruptive design approaches to enforce crucially needed step-change technologies.

The overarching aim of TACOS is to break the bottleneck of combustion instabilities by novel, physics-driven design principles based on latest theoretical findings: the combustion community -including myself- has discovered ""exceptional points"" (EPs), which are known from theoretical physics to feature intriguing, counter-intuitive physical properties.

Our preliminary results confirm that EPs (i) rapidly switch the combustor stability from unstable to stable and (ii) are well-controllable by both the acoustics of the chamber and the flame characteristics.

TACOS takes a leap forward and exploits the unique properties of EPs for the conception of novel combustors by 3 objectives: (A) tailor the characteristics of both gaseous (land-based gas turbines) and spray flames (aeroengines) by carbon-free fuels (hydrogen+ammonia) and sustainable aviation fuels; (B) optimize simultaneously the emission rates and the stability of the combustion chamber by designing the combustor close to the EP; and (C) quantify the design robustness by experiments at atmospheric and high-pressure conditions to learn design principles by explainable machine learning methods.

As a result, TACOS will not only produce an unprecedented, computer-aided and optimization-centric design software for safe, robust and clean gas turbines, but will also open a new research field on design principles and amplify fundamental breakthroughs in CI research.