Quick questions on Jet engine fundamentals: HSC Engineering Studies Aeronautical Engineering

A modern high-bypass turbofan (Rolls-Royce Trent 1000, GE GEnx, Pratt and Whitney PW1100G) has:

1. Intake. Air enters the inlet, slows and rises in static pressure slightly. 2. Compression. The compressor multiplies static pressure by 30 to 50.

The bypass ratio (BPR) is the ratio of mass flow through the fan duct (cold bypass air) to mass flow through the core:

where $\dot{m}$ is the mass flow rate through the engine, $v_e$ is the exhaust velocity relative to the engine, and $v_a$ is the aircraft true airspeed. For a turbofan, the sum of contributions from the fan duct and the core gives the total.

Qantas's Boeing 787-9 fleet uses the Trent 1000 (option) or the GEnx-1B (alternative). Each engine produces about 50 kN of cruise thrust, balanced against the 1 MN takeoff requirement during full-power climb.

Qantas-Boeing maintenance partnership (Hawker de Havilland operations at Bankstown and Tullamarine) provides on-wing maintenance and component repairs. The Royal Australian Air Force operates Pratt and Whitney F135 (F-35A) and General Electric F404 (F/A-18F) low-bypass military turbofans, plus T56 turboprops on the legacy C-130J Hercules transport fleet.

Bypass ratio is mass-flow ratio. Compression ratio is the pressure rise through the compressor.

The compressor is upstream of the combustor; the turbine is downstream. Both rotate together on the shaft. :::