A blended wing body (BWB) aircraft with embedded engines may be the best way to reduce noise levels around an airport to typical urban levels, according to early reports from a three-year study into jet noise by the University of Cambridge and Massachusetts Institute of Technology (MIT).
Six months of work has produced a range of designs, with BWB the leading model. The next step, after concept studies, is to test components such as engine air ducts in a wind tunnel, to understand airflow and its distortion.
The research is part of the Cambridge-MIT Institute's (CMI) silent aircraft initiative (SAI), led by Cambridge Professor Ann Dowling. She says that, as well as simply shielding the engine, "to reduce jet noise you need to get the thrust from lots of air moving [through the engine] slowly, not a small amount of air moving fast".
Predictions suggest that to reduce noise, engine airflow at take-off would have to be three times greater than current capacity. Materials for shielding the engines within the BWB have yet to be identified.
Launched in November 2003, the SAI is receiving £4 million ($7 million) in funding from CMI and aviation industry partners and will run till November 2006. Partner organisations include Rolls-Royce, Marshall Aerospace, the UK Civil Aviation Authority, National Air Traffic Services, British Airways (BA) and BAA.
ROB COPPINGER / LONDON
Source: Flight International
