Session: 01-14: Whole Engine Performance and Novel Concepts I

Submission Number: 177320

Influence of Operation Mode on the Performance and Component Matching and Multi-Objective Optimization of a Multi-Stream Adaptive Cycle Engine 

The multi-stream adaptive cycle engine (ACE) represents a transformative propulsion concept for next-generation aircraft, offering the capability to dynamically balance thrust, efficiency, and thermal management across widely varying mission conditions. By incorporating multiple variable-geometry mechanisms and controllable bypass or adaptive streams, the ACE can transition seamlessly between high-thrust and high-efficiency modes. However, these additional degrees of freedom complicate component matching, stage coordination, and overall performance control, particularly during transitions between operating modes.

The present study investigates the influence of operation mode and variable geometry setting on both the performance and component matching characteristics of a representative multi-stream ACE (tree-streams in total). A one-dimensional thermodynamic cycle model was developed to simulate steady-state under varying control schedules. The model includes bypass and adaptive-stream control valves, and variable-area nozzles, allowing the coordinated adjustment of flow distribution and pressure ratios among the core, bypass, and adaptive streams.

Two representative operation modes were analyzed to capture the adaptive operating characteristics of the multi-stream engine. In the high-thrust mode, the engine operates with increased core flow and elevated pressure ratio to generate augmented thrust during takeoff or combat conditions. In contrast, the cruise-efficiency mode directs a greater proportion of mass flow to the bypass and adaptive streams, thereby enhancing propulsive efficiency and reducing specific fuel consumption (SFC) during sustained cruise operation.

Through detailed component matching and stage performance analysis, the effects of variable geometry scheduling on compressor and turbine operating points, work balance, and overall cycle efficiency were quantified. Overall, this work aims to provide a comprehensive understanding of how variable geometry and operating mode jointly affect engine performance as well as component matching. The findings contribute to the development of control-oriented modeling strategies and adaptive scheduling algorithms for next-generation multi-stream adaptive propulsion systems, supporting future applications in intelligent, energy-efficient, and mission-flexible aerospace propulsion.

Presenting Author: Jiasen Xu Institute for Aero Engine, Tsinghua University

Presenting Author Biography: Xu Jiasen is a current Master's student in Mechanical Engineering at the Institute of Aero Engine, Tsinghua University. His research primarily focuses on feature identification of aero-engine systems. The methodologies he employs have been successfully extended to several critical areas, including aerodynamic optimization design of key engine components, performance prediction, and health status assessment, achieving notable results.

Authors:

Jiasen Xu Institute for Aero Engine, Tsinghua University
Qianrong Ma Taihang Lab
Fangyuan Lou Institute for Aero Engine, Tsinghua University