Session: 01-08 Whole Engine Performance and Novel Concepts II

Paper Number: 103912

103912 - Integrated Design of a Variable Cycle Engine and Aircraft Thermal Management System 

The integrated design of a variable cycle engine (VCE) and an aircraft thermal management system (TMS) is investigated. The integrated system is designed using the multiple design point (MDP) approach in order to achieve required performance metrics at points other than the cycle design condition. The VCE architecture under investigation is a three-stream design with a third-stream that is split off after the fan, exhausting through a separate third-stream nozzle. The primary air stream passes through a low-pressure compressor before splitting into an inner bypass stream and a core stream. The inner bypass and core streams mix aft of the low-pressure turbine and exhaust through a single core nozzle. The variable cycle engine utilizes multiple variable geometry components, including variable compressor inlet guide vanes (IGVs), a variable area bypass injector (VABI) at the inner bypass / core stream mixing plane, and variable throats in the two exhaust nozzles. The TMS architecture modeled is an open-loop air cycle system (ACS) that uses air bled from the high-pressure compressor as the working air. The bleed air passes through heat exchangers (located in the engine third stream) before and after passing through a separate supercharging compressor, and is then expanded through a turbine to reach the low temperatures required to absorb heat from the aircraft cooling system. A comparison is made to prior studies, where the same TMS architecture was connected to a low-bypass ratio turbofan engine, with the heat exchangers placed in either a ram-air stream or the engine bypass stream. The comparison shows that the variable cycle engine is able to achieve similar cooling capability to a ram-air cooled system, while reducing the airframe integration impact that comes with a separate ram-air stream. In addition, the impact of modulating the variable geometry features on overall cooling capability is investigated.

Presenting Author: Robert A. Clark Georgia Institute of Technology

Presenting Author Biography: Robert Clark is an NDSEG Fellow at the Aerospace Systems Design Laboratory at the Georgia Institute of Technology. Robert previously spend four years at GE Aviation designing aircraft engines and components, and is a graduate of the Edison Engineering Development Program.

Authors:

Robert A. Clark Georgia Institute of Technology
Jimmy Tai Georgia Institute of Technology
Dimitri Mavris Georgia Institute of Technology