Hybrid aircraft

Figure 36.6 Trade-ofT between hybridization degree and power requirements of a fuel-cell hybrid aircraft. Reproduced from [23].

Hybrid Aircraft Aircraft that is able to rise and land like a helicopter but convert in flight to the speed of a fixed-wing aircraft. 

Hybrid aircraft can perform both functions to a considerable extent and appear to be the way of the future in the development of new aircraft systems. The existing hybrid craft are used solely by the military. The V-22 Osprey is a tilt-wing system developed by Bell Boeing, and the Harrier Jump Jet is a British creation that uses a variable nozzle system to redirect power. 

Aircraft use can he broken down into two m or markets military and civilian. The military has three m or categories of use fixed-wing for combat and transport, rotary-wing for combat and transport, and the emerging hybrid aircraft. The civilian market has two areas for use transport of cargo and people. 

The major deviation is the increasing use of the V-22 Osprey by the Marines. This hybrid aircraft has the variable wing design, which allows it to hover like a helicopter as well as travel and maneuver like a fixed wing between sites. 

ARALL laminates, a family of hybrid composites consisting of aramid fibers bonded with epoxy between 0.3 mm thick aircraft ahoy sheets, were introduced in the 1980s (53). The laminates have lower density than even the new Al—Li ahoys and are greatly superior to monolithic aluminum sheet in resisting the growth of fatigue cracks. ARALL laminates have been specified for aircraft stmcture which is subjected to cycHc tension loads (see Laminates). 

Hybrid materials are often a good solution to take advantage of plastics and one or several other conventional materials. This principle, in more or less complex versions, is applied to the front-ends of recent cars, footbrake pedals, aircraft wheels, car doors, etc. 

Div, Research in Hybrid Combustion, Final Rept R-5179 (Dec 1961 thru Jan 1963). [Contract 3016(00)] 6) United Aircraft Corp,... 

Parts in Aircraft s auxiliary power unit Hybride ball bearing in the space shuttle... 

The high reliability of Si3N4 ceramics is demonstrated by hybrid bearings in the main engine pump of the space shuttle [644] and different components in the aircraft s auxiliary power units [650, 651],... 

The DLC market is expected to grow rapidly to reach the billion dollar size. Hundreds of millions of small size DLCs (IF, 5V) are used in the consumer electronic market for more than 20 years. Millions of larger size DLCs (350F, 2.5 V) have already been installed in industrial applications, like wind turbine pitch systems, since 2002. Today DLCs are already used in the car industry, as for example in the breaking actuator system of the Toyota Prius hybrid car, and in the aircraft industry, as for example in the door opening system of the Airbus A380. 

Two case studies are presented in which polymer nanotube composites are proposed as replacements for conventional materials. We evaluate the technical and economic feasibility of using them as smart materials for strain gauges thus, exploiting their electrical properties, and as structural materials for aircraft panels bringing into play their mechanical properties. Our analysis shows that as new strain gauge materials, polymer nanotube composites offer many advantages. As a possible replacement for aluminum in an aircraft panel, it is found that a hybrid composite of (Epoxy 33% carbon fabric + 30% carbon fibers + 3% CVD-MWNT) is an attractive candidate. 

Johnson, J.L. and McKinney, J.L., Electrical-Power Brushes for Dry Inert-Gas Atmospheres, IEEE Trans. Part 5, Hybrids and Packaging, 7, 62, (1971). Nelson, R.E., Improved Carbon Brushes for Aircraft Electrical Machines, WADC TR-57-170, (Jan. 1960). 

Construction refers to a manufacturing fadlity in which the end product instances rarely move equipment is moved into the product area and processes and component installations are performed on the product in place. The principal examples are shipbuilding and spacecraft, but aircraft manufacture is a hybrid of construction and assembly line approaches. 

In one example, a UV aerobic acrylic replaced an epoxy adhesive in an aircraft application. Epoxy adhesives frequently have been used to bond through-hole hybrid eomponents onto PC boards. This prevents breaking of the fragile leads under common aircraft stresses sueh as temperature changes and vibration. 

Current civil aircraft applications have concentrated on replacing the secondary stracture with fibrous composites where the reinforcement media have either been carbon, glass, Kevlar or hybrids of these. The matrix material, a thermosetting epoxy system, is either a 125 °C or 180 °C curing system with the latter becoming dominant... 

Business aircraft made from RPs include the mainly glass fiber Chichester Miles Leopard (UK) and the Raytheon Permier 1 six-seater, notable for a largely filament-wound carbon-epoxy/honeycomb/ carbon-epoxy fuselage. A hybrid light jet aircraft was developed in the... 

Compounds of aluminum with transition elements attracts wide attention due to the need of high-performance structural materials in the aerospace, aircraft and automobile industries. The most promising candidates are compounds of aluminum with scandium, titanium, vanadium, and chromium. These transition metals have the outer electron shells 3d 4s, 3d 4s, 3d 4s, and 3d 4s respectively. Aluminum has the 3s 3p outer electron shell. The interatomic bonding in structures of trialuminides results from the overlap d-orbitals of transition metals with the hybridized sp orbital of aluminum. 

Polymer adhesives have found their place in numerous electronics applications. Major uses include eommercial/consumer products computers and military, space, automotive, medical, and wireless communications. Some adhesives may be used aeross several applications while others have been formulated to meet applieation-specific requirements. For example, reworkability is not a consideration for high-production, low-cost consumer products such as cell phones or calculators, but is important for high-value, high-density printed-wiring boards (PWBs) used in military and spaee electronics. Further, thermal stability at high temperatures is required for near-engine electronics in automobiles, aircraft, and for deep-well sensors, but not for office computers. The major applications for polymer adhesives are to attach and electrically insulate or to electrically connect components, devices, connectors, cables, and heat sinks to printed-circuit boards or to thin- or thick-film hybrid microcircuits. In addition, over the last several decades, new uses for adhesives have emerged for optoelectronic (OE) assemblies, microelectromechanical systems (MEMS), and flat-panel displays. 

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