Abstract One of the most important new engine concepts is Geared turbofan. In these engines a gear box allows decoupling between fan and turbine rotational speeds. As consequence, separate aerodynamic optimization both components becomes possible leading to an increase in bypass ratios, higher propulsive efficiency lower specific fuel consumption. The multi-stage intermediate pressure (IPT) one...

A laboratory experiment was conducted to quantify the annoyance response of people on the ground to en route noise generated by aircraft at cruise conditions. The en route noises were ground-level recordings of eight advanced turboprop aircraft flyovers and six conventional turbofan flyovers. The eight advanced turboprop en route noises represented the NASA Propfan Test Assessment aircraft oper...

This is an exploratory study of jet noise reduction using fan flow deflectors in a nozzle shaped like the exhaust of a separate-flow turbofan engine with bypass ratio 4.8. The deflectors directed the bypass plume downward and/or sideward relative to the core plume. Vaneand wedge-type deflectors were tested. The noise reduction achieved by the vane deflector was strong in the downward direction ...

Pollution emission levels of aircraft engines are a nowadays high concern. Any technological advance that could reduce emission levels is always welcome. In what concerns aircraft engines, a possible solution for this problem could be the use of regenerators and intercoolers. These components might reduce the specific fuel consumption, increase efficiency and specific thrust and consequently re...