Graham Warwick/ATLANTA
PRATT & WHITNEY Canada has completed initial tests of Calcor Aero Systems' thrust-reverser/variable-exhaust-nozzle (REVEN) on a PW306. Calcor says that the engine runs, in a Toronto test cell, give it confidence that the nozzle will reduce specific fuel consumption (SFC) and increase thrust in altitude tests which P&WC hopes to conduct in 1997.
The REVEN is designed to improve engine performance by allowing nozzle exit-diameter to be varied by up to 15%, to optimise airflow efficiency. The target-type thrust reverser, meanwhile, maintains the existing nacelle-exterior and jetpipe-interior profiles.
Whittier, California-based Calcor says that the P&WC tests demonstrate that the REVEN is the first thrust-reverser design to maintain precisely the inner and outer flow lines of the manufacturer's reference nozzle.
Tests were conducted with the reverser doors closed, and with nozzle apertures sized from 3.6% smaller to 3.1% larger than the reference nozzle.
At each aperture, the company says, the REVEN remained fully sealed, with no gaps in the flow lines, and displayed flow pressures identical to those of the reference unit. From flight idle to 27kN (6,040lb) thrust, according to Calcor, reference spool speeds and turbine temperature were maintained. Because of these initial sea-level tests, the company believes that altitude testing will demonstrate the thrust and SFC improvements claimed for the REVEN.
P&WC's PW306 is a 24kN business-aircraft turbofan. Calcor's variable exhaust-nozzle will also be tested on the 133kN-thrust International Aero Engines V2500 turbofan in early 1997.
REVEN is claimed to be first thrust reverser to maintain flow lines
Source: Flight International
