GE Affinity Turbofans to Power AS2

摘要

GE Aviation and Aerion jointly are developing the first engine in more than half a century to power a civil supersonic aircraft. GE's 20,000-lb.-thrust-class Affinity is a low-risk design that uses a high-pressure core adapted from the CFM56 jetliner turbofan and GE F101/F110 military engines, upgraded with thermal barrier coatings and other improvements to assure reliable, prolonged operation at supersonic speeds up to Mach 1.6 and up to a 60,000-ft. operating altitude. The core features a nine-stage axial-flow compressor powered by a single-stage high-pressure turbine with a pressure ratio close to 10:1. The core will be mated to a new two-stage, medium-bypass fan powered by a two-stage low-pressure turbine. The bypass ratio will be the highest ever for a supersonic engine at close to 3:1. However, it will be lower than for today's subsonic business aircraft, most of which are powered by turbofans with 4:1 to 6:1 bypass ratios that produce comparatively modest pressure ratios for low noise and best fuel efficiency. The Affinity's fan bypass ratio should be nearly 2:1, thereby boosting the overall pressure ratio to 20:1, almost ideally matched to the AS2's Mach 1.4 top cruise speed. The Affinity will produce sufficient thrust for supersonic flight without the need for an afterburner.