A Study on Combined Variable Geometries Regulation of Adaptive Cycle Engine during Throttling

• Main Authors: Ya Lyu, Hailong Tang, Min Chen
• Format: Article
• Language: English
• Published: MDPI AG 2016-11-01
• Series: Applied Sciences
• Subjects: adaptive cycle engine; variable geometries modulation; maintain airflow during throttling; spillage
• Online Access: http://www.mdpi.com/2076-3417/6/12/374

The most remarkable variable cycle characteristic of the variable cycle engine (VCE) is that it keeps airflow almost constant during subsonic cruise throttling by modulating variable geometries, which can efficiently decrease spillage drag and increase installed thrust. One of the most critical challenges for the modulation lies in completely maintaining airflow, as well as avoiding specific fuel consumption (SFC) degradation during throttling. This has resulted in a need to investigate the modulation regulation of the adaptive cycle engine (ACE) which is a new concept for VCE and has greater potential for flexibly modulating airflow and pressure ratio. Thus, the aim of this paper is to study the variable geometries’ modulation schedule of ACE in maintaining airflow during throttling. A configuration of an ACE concept and its modeling study are first put forward. Then, the control schedule is researched via the combination of sensibility analysis and basic working principle instead of optimizing them directly. Results show that when the net thrust decreases from 100% to about 55% during subsonic cruise and to 32% during the supersonic cruise, the demand airflow of the engine is kept almost constant, which greatly improves the installed performance during throttling.