Altitude-Dependent Analysis of Combustion Performance and Emissions in a Commercial Aircraft Engine Leveraging Real Engine Data

Abstract This study provides a comprehensive numerical investigation of altitude-dependent combustion performance and emissions of a commercial aircraft engine, leveraging real engine data to evaluate kerosene-fueled operation across six flight levels: FL300, FL318, FL336, FL354, FL372, and FL390. The combustion chamber geometry was modeled using Siemens NX, simplified in ANSYS SpaceClaim, and meshed with a five-layer inflation strategy to ensure proper boundary layer resolution. A high-quality mesh was achieved, and a mesh independence study was conducted to ensure numerical accuracy. Using the realizable k –ε turbulence model with enhanced wall treatment and an eddy-dissipation approach for turbulence-chemistry interactions, the results show that lower flight levels are associated with higher combustion efficiency, with peak temperatures exceeding 2500 K at FL300. Conversely, higher altitudes demonstrated reduced combustion efficiency and increased unburned fuel fractions, providing insights into the performance and environmental impact of altitude-dependent aircraft operations. These results may assist in optimizing engine design and operational strategies for improved fuel efficiency and reduced environmental impact across varying altitudes.