Session: 01-13: Thermal Management and Aero-engine Oil Systems II

Submission Number: 178016

Operational Characteristics and Pre-Cooling Strategy of a Precooled Turbojet 

The precooled turbojet (PCTJ) enables hypersonic flight by utilizing a precooler for rapid heat exchange with the high-temperature incoming airflow, thereby maintaining the turbine engine within its optimal operating range. In recent years, the PCTJ has emerged as a pivotal technology for reusable hypersonic propulsion systems. The complex interplay between hypersonic flight conditions and precooler operation creates intricate internal coupling within the PCTJ, a phenomenon that remains systematically underexplored in the open literature. This study establishes, through theoretical derivation, a mapping between the optimal precooling temperature and the flight Mach number, thereby delineating the engine's theoretical operational envelope. Results reveal that the intake capture area is a decisive constraint on the upper-speed limit, which is determined to be Mach 4.3 under the baseline conditions examined. Then, a comprehensive performance model for the Precooled Turbojet (PCTJ) was developed by integrating a low-dimensional precooler model. This integrated model was applied to optimize a PCTJ design for a Mach 4 flight mission and to analyze the engine's wide-speed operational characteristics. The results demonstrate that the optimized precooler design reduces the precooling initiation Mach number to 1 and significantly enhances propulsion performance at low-to-medium Mach numbers. Specifically, at Mach 2.5, the engine outlet pressure and mass flow rate are increased by up to 99.2% and 117.4%, respectively.

Presenting Author: Yusen Xu Research Institute of Aero-Engine, Beihang University

Presenting Author Biography: Yusen Xu, male, from China, is currently pursuing his Ph.D. at Research Institute of Aero-Engine, Beihang University. His research focuses on precooled engines and their wide-speed-range propulsion characteristics.

Authors:

Yusen Xu Research Institute of Aero-Engine, Beihang University
Yifan Wang Research Institute of Aero-Engine, Beihang University
Huoxing Liu Research Institute of Aero-Engine, Beihang University
Kun He Research Institute of Aero-Engine, Beihang University