Session: 03-06 Innovations in Hydrogen and Ammonia-Based Propulsion Systems

Paper Number: 153011

Simulation Study of a Turbofan Engine With Ammonia As Energy Carrier 

The shift from a conventional Jet-A combustion engine to a zero-carbon emission aircraft engine such as an ammonia-cracked hydrogen combustion engine is integral to decarbonizing aviation. This paper proposes a novel design for integrating the ammonia cracking section into a high-bypass, two-shaft turbofan engine, like the one used in the Boeing 737 Max, modeled as a steady-state Brayton cycle using the Aspen Plus software. The design addresses the hydrogen storage issue while improving ammonia's combustion characteristics and minimizing NOx generation. First, a baseline turbofan engine model fueled by Jet-A is validated against parameters from existing literature. Once validated, an ammonia cracker-combustor interloop is incorporated into the model, thus replacing Jet-A with an ammonia-hydrogen blend. Heat for ammonia cracking is supplied by the combustion chamber. The ammonia conversion rate impacts the system efficiency as it determines the amount of hydrogen produced from the cracking reaction. Therefore, cracking conditions are optimized to obtain a high conversion rate. Finally, thermodynamic analyses are conducted to investigate the performance of the ammonia-based design in the cruising operation mode. Aspen Plus software is selected for the entire simulation due to its reliable thermodynamic properties and calculations as well as its ability to perform transient analysis which will be required for future studies. In essence, this model aims to seamlessly integrate the ammonia cracker-combustor flow path into the turbofan engine while evaluating the required fuel consumption and system performance relative to the baseline Jet-A model.  

Presenting Author: Mairah Ahmed University of Central Florida

Presenting Author Biography: I am a first-year PhD student of Mechanical Engineering at the University of Central Florida. As a graduate research assistant at the Center for Advanced Turbomachinery and Energy Research (CATER) lab, I work on developing process designs that enable decarbonisation in aviation. My current research involves exploring ammonia as an alternative fuel in aviation and investigating techniques to integrate ammonia into existing aircraft engines using simulation software such as Aspen for process optimization.

Authors:

Mairah Ahmed University of Central Florida
Kangana Patel University of Central Florida
Andrew Menendez University of Central Florida
Ghanshyam Sarobar Mandal University of Central Florida
Marcel Otto University of Central Florida
Jayanta Kapat University of Central Florida