Milestones and Advances in Environmental Cleanliness from Pratt & Whitney
Pratt & Whitney this spring held a media event at its Hartford, Connecticut headquarters and provided an overview of its milestones and advances in environmental cleanliness and so on. Some samples:
• EcoPower engine wash will be available for the GE CF34 later this year. The detergent- and pollution-free process uses between 30 and 60 gallons of atomized water to clean an engine’s innards and improve efficiency by 1.2 percent. Cleaning effluent is collected, filtered and the water reused. Service is available at 18 locations serving 66 airports. “If every airline EcoWashed, one billion pounds of fuel and 3.2 billion pounds of [carbon dioxide] CO2 emissions would be saved annually,” said Anupam Bhargava, P&W EcoWash.
• Aviation accounts for 2 percent of CO2 emissions, and jetliners are now achieving 68 passenger mpg. The A380 and 787, however, will take passenger mpg to the mid-70s; and the GTF should add between 12 and 15 passenger mpg to the airplanes it powers, compared with current-technology alternatives.
• The PW4060 is 70 percent more fuel efficient and produces half the CO2 and 90 percent fewer hydrocarbon emissions, compared with the JT9D that powered the first Boeing 747.
• The GP7000 for the A380 has a bypass ratio of 9.5, the highest yet for a conventional turbofan. The GTF for Bombardier’s C Series will have a bypass ratio of 12.5 yet will be lighter than the equivalent engines it replaces–good for annual fuel savings of $1.5 million per aircraft at $2.50 a gallon. Compared with a 737-800 taking off from eco-vigilant Amsterdam Schiphol, a GTF-powered aircraft will be 77 percent quieter. P&W has spent $1 billion so far on the GTF program, and the engine has logged 12 flights aboard P&W’s 747 flying testbed and 27 flights aboard an Airbus-owned A340 flying testbed.
• The GTF’s fan speed will be less than 3000 rpm, and its tip speed will be one third slower than that of a CFM56-5B.
• P&W has certified five new engines per year for the past decade.
• “We could see continued drops in business jet deliveries next year, beyond just this year. This is different from what we’ve ever seen before. It’s a crisis of confidence, and we don’t know whether the recovery will be V-shaped, U-shaped or bathtub-shaped,” said David Hess, Pratt & Whitney president.
• “It’s a tough business case for field retrofits of the GTF. Residual values of older airplanes do not square with the value of the GTF engine,” said Todd Kallman, president of commercial engines.
• “Biofuels hold promise but ASTM qualification issues must be addressed. Feedstocks must not deprive the food chain,” said Paul Adams, vice president of engineering.
• A PW4090 sucks in one ton of air per second on takeoff. The PW4000 series burns about one quart of oil in 20 hours, versus between a half and one quart per hour for the JT8D.
• Only about 20 percent of compressor air is burned in the combustor; the remaining 80 percent cools the structure. Up to 8 percent of compressor air is used to cool the nozzle guide vanes, which accelerate the combustor outflow from Mach 0.1 to Mach 0.8.
• Some bearings now are handling 18,000 rpm versus just 6000 rpm on earlier turbine engines.