Green Technology

Effects of air and noise pollution surround us. No wonder airports, foreign governments, NASA and Honeywell customers have set tough new goals and incentives. Sweden and Switzerland have also implemented airport landing fees as economic incentive to reduce pollutants and encourage investment in green technology.

Research programs have Honeywell well prepared to meet new environmental or green goals for drastically reducing pollutant and noise emissions and improving the quality of cabin air.

Pollutant Reduction
Honeywell's advanced technology team leads development of low emissions technologies that meet new standards.

The team focuses on reducing nitrogen oxide (NOx) emissions that contribute to ozone depletion and carbon monoxide (CO) emissions that are toxic in high concentration. Honeywell plans to reduce NOx emissions by 50 to 70 percent. Most NOx forms at take off power when fuel and air are mixed and burned at high temperatures and pressures. CO and unburned hydrocarbons result mainly from incomplete combustion at low power. To minimize NOx and CO emissions, the combustor system must control flame temperature over the full range of engine power.

An advanced technology combustion team is developing two promising NOx reducing technologies, lean-direct-injection (LDI) and rich-quick0mix (RQM). LDI and RQM combustor technologies seek to lower the temperature of the combustion (primary) zone by burning fuel-lean and fuel-rich, respectively. In turn, lowered primary zone temperatures will significantly reduce NOx emissions, with minimal impact to CO and smoke emissions.

Combustor designers are challenged to balance competing goals - creating affordable technology without adversely impacting engine performance, durability and reliability. For example, LDI offers high potential, but could increase complexity and cost and reduce operability. Although less complex, RQM is more apt to impact smoke and durability.

Honeywell breaks new ground in spray research with a tool that characterizes atomizer spray structure. A high pressure laser diagnostics spray facility produces three dimensional color images, like a CAT-SCAN, to analyze atomizer fuel mass and droplet size distributions. This unique industry capability provides insight into atomizer mixing to lower emissions.

Noise Reduction
Noise emission concerns aircraft operators, airports, and nearby communities.

Local airport noise rules are becoming increasingly stringent. Now a new aircraft must achieve as much as 18-25 decibels of noise reduction relative to the current Federal Aviation Administration requirement, if they are to avoid operating restrictions and fines. Some local airport rules even disallow or severely restrict use of an auxiliary power unit. Furthermore, airport community demands mean suppliers have to meet still more sets of noise reduction goals.

Honeywell propulsion engines, like the AS907, already incorporate sound absorbing acoustic panels in engine duct walls. They have selected rotor and stator counts that help reduce noise generated by the turbomachinery and include a mixer that significantly reduces jet noise relative to the alternative separate flow nozzle.

To meet new requirements, Honeywell is researching a number of noise reducing concepts for propulsion engines and auxiliary power units (APU). Researchers participate in NASA technology with the goal of cutting noise emission in half. A new forward-swept fan design is one of several technologies that will help achieve that goal. The fan will be validated by rig testing this year. Other new concepts include advanced materials for acoustic liners, novel APU duct geometries that help trap noise, and a new APU design.

Cabin Air
The air quality team brings technology breakthroughs to Honeywell customers - resolving legacy issues and introducing future aircraft products.

Honeywell works along side key customers to find innovative solutions that will meet passenger and flight crew demands for high standards in cabin air quality. Problems addressed range from environmental ozone that can be ingested into the aircraft cabin while at altitude, to hydrocarbon odors that tend to be ingested while on the ground at airports.

Honeywell environmental control systems and strong chemistry and catalysis capability are well established. Honeywell environmental control systems already feature advanced technology like catalytic ozone converters. Now, Honeywell has developed a new combined hydrocarbon, ozone converter (CHOC), a new catalytic system with duel functionality. Not only does the system remove ozone, it solves nagging odor problems for air carriers as well.

The team is also developing a catalytic precooler that combines catalyst functionality with the environmental control system precooler, thereby reducing the number of line replaceable units - an obvious cost and weight saver.

A breakthrough air purification system, incorporating Honeywell's photocatalyst technology, will treat circulated air on future aircraft. The low temperature air purification system removes chemical odors and offers a significant advantage for low and no bleed aircraft systems of the future.