Session: 04-12: Ignition I

Paper Number: 82951

82951 - Numerical Study of High-Altitude Relight for an Aviation Gas-Turbine Engine 

The altitude relight capability of an aero-engine is one of the critical requirements, that defines the operational flight envelops of the engine. Regulatory requirements from Federal Aviation Administration (FAA) and European Union Aviation Safety Agency (EASA) ask for the establishment of the altitude and airspeed envelope for in-flight engine restarting, and adherence of engine performance for that. Further, engine manufacturers are making changes to the combustor designs to meet the aggressive goals of limiting the emission of nitrogen oxides (NOx). While these design changes help in reducing the NOx formation, they can be problematic for restart capabilities at a higher altitude. Therefore, the engine design process becomes a complex optimization problem with conflicting goals. Test-rig data can provide insights about the performance but using that to explore all design space is challenging, expensive, and sometimes not feasible. In this scenario, high fidelity computational fluid dynamics (CFD) simulations can help in bridging this gap and therefore, are being widely evaluated by design and simulation engineers. In general, the simulation needs to resolve flow structures, spray distribution, and ignition process with reasonable accuracy to predict the high altitude relight, accurately. Moreover, there should be no, or limited parameter adjustments required for correctly predicting the relight condition across different operating conditions.

In this work, numerical simulations are performed to predict the relight performance of an aviation gas turbine combustor operating at different operating conditions including that at sea level and at 30000 ft. Several operating conditions are simulated. The simulations are performed using the URANS approach along with a solution adaptive meshing and finite rate combustion modeling to track the flame propagation post the spark event, with required accuracy as this is the backbone for accurately predicting the light or no-light condition at a given operating point. The results are encouraging and predict accurate behavior of lighting and not lighting operating conditions consistent with the results from the experimental tests. The simulation methodology, best practices, and obtained results are discussed in this paper.

Presenting Author: Pravin Nakod ANSYS Inc

Presenting Author Biography: Pravin is a simulation expert and currently working as a senior manager of application engineering at Ansys Inc. managing a team of experts developing cutting-edge simulation solutions for different industrial applications. Personally, he has been focused on numerical combustion and pollutant modeling for gas turbine engines and has been consistently presenting his work at ASME Turbo Expo and GT India conferences. Recently, he is looking at expanding simulation approaches for clean energy initiatives, especially related to hydrogen energy and electrification.

Authors:

Giuliana Litrico Ansys Inc
Sourabh Shrivastava Ansys India Pvt. Ltd.
Ellen Meeks Ansys Inc.
Pravin Nakod ANSYS Inc
Fang Xu Honeywell Aerospace
Dhanya T Honeywell Technology Solutions
Sivaprakasam Muthuraj Honeywell Technology Solutions