Monday, May 17, 2010

Delos Aerospace Developing Wheel Motor Landing Gear System for Aircraft



Delos Aerospace has announced technology to reduce aircraft fuel burn reducing greenhouse gas production and increase airport and aircraft capacity utilization.

Delos holds two patents for technology that provides for the optimal efficiency in aircraft ground maneuvering by incorporating the use of in-wheel electric motor/generators that are capable of producing sufficient power density to effectively maneuver aircraft of any weight on the ground, and provide for safer and more effective braking of the landing gear wheels.

This revolutionary technology is a total systems integration of a fully electric landing gear and maneuvering system wherein axial flux disk motor/generators replace the old friction disk technology providing increased braking and maneuvering capability to the aircraft wherein there are many engineering benefits to eliminating the heat generated within friction based braking systems.

This fully integrated electric braking and maneuvering system and method allows for higher levels of effective braking and maneuvering capability to be applied to aircraft without the use of jet engines which is a safer and more effective braking and maneuvering system (forward, reverse and steering) than current systems used at a reduced overall weight that can also assist in takeoff thus allowing for reduced thrust levels required by the jet engines wherein these applications reduces the required fuel weight by 1200 lbs for average airline flight times of 60-90 minutes and over 4,000 lbs for larger airliners that might fly out of LaGuardia Airport for example thus directly impacting payload and range capacity.

Currently jet and turbofan aircraft require tow motors or tugs to push the aircraft backward into the designated taxiway. This is an added operational cost in ground support material and personnel for the airline or cargo operator. By eliminating the need to wait for, attach, and detach tow motors or tugs aircraft can enter and exit gates faster thus reducing between-flight turnaround times which directly impacts Airport capacity utilization and airline operators' revenue. This means that on many routes, total trip times can be reduced, enabling an aircraft to make more flights per day thus increasing an airline's capital-asset utilization rate.

Delos technology can provide for increases in airline operators' revenue by eliminating fuel burn during ground maneuvers, reduce fuel burn at takeoff, reduce gate charges, reduce turnaround cost, and provide for reductions in MRO costs due to brake system overhauls and reduced maintenance frequency of the jet engines thus ensuring that airplanes spend more time serving passengers.

There is the added benefit of reduced air and noise pollution in and around airports thus significantly impacting the environment that is of a growing concern among many.

Overall operating cost savings from incorporating Delos technology are expected to total 2.6 to 2.8 million USD a year per commercial airliner aircraft.

Principal benefits of Delos technology include:

. Fuel savings. With Delos technology the primary engines need be turned on only at the end of the runway, immediately before takeoff, and can be turned off immediately after landing. Delos technology will brake the aircraft upon landing by converting the kinetic energy of the aircraft into electrical power and store that electrical power onboard the aircraft using lightweight nano enhanced ultra-capacitors. The stored energy is later used to motor the aircraft wheels in the taxiways and runways. For many short-haul routes (60-90 minutes), taxiing and takeoff-waiting times can be a large fraction of total trip time 20-33%, and the fuel savings on these routes can be substantial for large commercial airline operators.

. Faster flight turnarounds. By eliminating the need to wait for, attach, and detach tow motors or tugs, aircraft can enter and exit gates faster, reducing between-flight turnaround times. This means that on many routes, total trip times can be reduced, enabling an aircraft to make more flights per day and increasing an airline's capital-asset utilization rate.

. Decreased operational cost due to the fact that there are no friction disk to be replaced due to wear as magnetic torque is used to brake the aircraft wherein there are no friction disk wear items thus no need to overhaul the braking system and thus no need to remove the aircraft from service.

. Reduced engine wear. By reducing the throttle setting on the jet engine during assisted take-off and reducing the time the engines are running, wear-and-tear are reduced on the aircraft engines thus reducing the frequency of mandatory engine maintenance.

. Reduced airport charges for towing and gate usage.

. Reduced air and noise pollution in and around airports. The environmental benefits of Delos technology for airport neighborhoods will be substantial.

. Elimination of tug stress damage to aircraft. Aircraft are occasionally damaged when a tug stops but the aircraft it is towing (with much larger mass) does not thus applying stress damage the aircraft; Delos technology eliminates this risk and cost.

Any airplane can be equipped with Delos technology including civilian craft such as Boeing and Airbus jetliners, regional and business jets, as well as military aircraft ranging from transports and refueling craft, bombers, fighters and unmanned aerial vehicles UAVs.

Delos technology when implemented into aircraft represents a radical advance in landing gear technology and design implementation, eliminating the same materials and components that have existed for decades. Delos major advance is in implementing a fully integrate electrical motor/generator system within the landing gear wheels for use in a fully electrical aircraft landing gear system that has a feedback capability that is 1000 times faster than hydraulically actuated systems and is 100 times faster than the latest electrically actuated systems thus the effectiveness of the ABS and automatic braking are much higher adding to the safety level of the aircraft.

Conventional friction based brakes actually prevent effective levels of braking from occurring at very high power levels due to the fact that friction based systems are much slower in feedback capability than that of a fully electrical system and the braking capacity diminishes as the friction based brakes heat up and is known as brake fade. As a result, Delos technology provides for a higher level of effective braking and is more capable to meet the challenge of braking a large commercial aircraft, whether it is a 737, 787 or even an A380. Friction-based brakes can also affect the aircraft turn around time as they require time to cool down before they can be used again (30 minutes or more).

The heat generated by the friction disk within the wheel hub migrates to the tires and causes the tire to balloon or stretch and requires additional material to prevent the tire from exploding thus adding weight to the tire structure. Thus redesign could allow for further weight reductions in tire and wheel structures further improving fuel burn.

There is the added benefit of adding gyroscopic stabilization to the aircraft by spinning up the landing gear tires prior to touchdown minimizing wake vortex wind influence caused by preceding large aircraft thus increasing the level of safety for smaller aircraft which could allow for shorter separation distances for aircraft thus further increasing airport capacity.

Also by matching the tires rotational velocity with the relative ground speed the impulse of the landing event which normally causes the tires to spin up from zero rpm to over 1000 rpm in one half a second is eliminated thus reducing the impulse stress on the aircraft landing gear and airframe which also increases the passenger comfort by reducing the physical jolt experienced during a landing event with the added benefit of starting out in a rolling friction state as opposed to a sliding friction state as with current friction disk braking systems. Effective braking only occurs in the rolling friction state thus effective braking can be implemented immediately at touchdown not a few moments later when the tires are up to speed as is the case when landing on a contaminated landing surface such as that due to ice and/or snow.

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