Bruel & Kjaer's system can also compute EPNL
values including background noise, flight track and weather corrections for test validation and management of the tests.
NASA studied the amount of EPNL reduction for the following nozzle configurations: chevrons were installed only on the fan exhaust, only on the core exhaust, and on both.
A substantial benefit in EPNL occurs when the vanes have dissimilar angles of attack, with the upper pair at smaller incidence than the lower pair.
They also considered the addition of a porous wedge-shaped fan flow deflector and show FFD increases the EPNL reductions to 5.
Through these discoveries, EPNL has demonstrated the prospectivity of a new oil play, which is known as "deep Delta".
Thus, Elf thoroughly reinforced its position in Nigeria and EPNL is now one of the major subsidiaries of the Elf group in terms of proven reserves.
Two years later, EPNL was able to propose a revised project with a 30% reduction in capital cost.