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Combustion Concepts for the Next-Generation Aircraft Engines

Project Number: 051
Category: Aircraft Technology Innovation, Emissions

The purpose of this project is to identify future aircraft engine designs that could increase the efficiency of future aircraft while simultaneously reducing emissions. Historically, aircraft engine design has been a sequential process. Fixed fuel characteristics are used as an input to create the thermodynamic cycle for which performance and fuel consumption can be determined. Based on these results, a combustor is designed that satisfies operability and emissions requirements.

However, there is a range of engine technologies for which interactions between fuel, cycle, and combustor can be exploited to improve system efficiency. In this project, we plan to develop engine concepts with promising new technologies including water injection, exhaust gas recirculation and plasma assisted combustion. We will determine and compare performance characteristics associated with these technologies and will leverage detailed combustion chemistry models to understand how changes in fuel composition effect engine performance and emissions characteristics.

Outcomes

This project will provide novel capabilities to efficiently evaluate the performance of aircraft engine designs that involve the co-optimization of fuel, combustor, and engine cycle.  This includes developing simulation models which can be used to evaluate different concepts and applying these models to quantify the potential benefits of selected new combustion technologies including:

  1. Using high-reactivity additives as a means of extending the lean blowout limit of the combustor;
  2. Using water injection to extend the combustion operating envelope and reducing emissions; and
  3. Determining the feasibility of using reducing agents, for example urea, introduced downstream of the flame, to convert NOx formed in the flame.

Updated 3/31/2020

Program Managers