Question

Identify and describe some new technologies that are being applied in the design process of

aeronautical systems. Provide some examples of typical applications.

Answer 1

Some of the new technologies being used are

1.USE OF COMPOSITE; Nowadys specialized military aircraft, fighters, and vertical takeoff and landing (VTOL) aircraft, have composite structures.The advantages of composite materials, as exemplified by their greater strength and stiffness per unit weight, superior fatigue and corrosion resistance for many applications, and potential for lower manufacturing costs through reduced part counts and tooling expenses, make their wide application to U.S. aircraft designs a compelling need. However, the slow rate at which they are being adopted is evidence that their design, analysis, manufacturing, inspection, and repair methodologies are all in a developing state.

2.Smart Structures;Adaptive structures is a relatively recent concept that offers potentially important benefits in aircraft design. If, for example, a wing or wing section can be made to adapt its shape to maximize aerodynamic performance or minimize load regardless of flight regime, this could be a significant advantage—particularly if it were to reduce the number of moving parts. This technology began, in one sense, with the so-called control-configured vehicle concept and has grown to include compliant materials and structures combined with embedded sensor/processor/actuator systems.

3.Active Control;active control of internal noise and for reducing structural dynamic loads, stabilizing various aeroelastic phenomena having the potential for destructive instabilities, and improving crew and passenger comfort by reducing vibrations. Their impact, taken together with applications of automatic feedback control techniques, particularly in providing solutions to aeroelastic instability problems, will be continually increasing.

Acoustics

Acoustics issues are of sufficient importance to warrant basic research to improve fundamental understanding and accumulate the technical knowledge required for practical application of noise control methods of all kinds for rotorcraft, high-subsonic and short-haul transports, and GA aircraft. This will require analytical methods for predicting noise generation and propagation characteristics reliably, as well as research on human reaction to noise, including sonic boom. Increased information on the effectiveness of active noise control techniques is required to an extent sufficient to allow reliable trade-offs to be made, at the design stage, among active and passive treatment alternatives, cost, reliability, and range/payload. This applies to acoustic sources of all kinds—aerodynamic, propulsive, and those generated by dynamic system components—and to both interior and exterior noise.

4.Regulatory Aspects

The weight savings possible with composite structural materials are limited by inspection capabilities and damage design criteria. Both need additional emphasis. Differences in criteria should be addressed by NASA and the FAA to the extent that safety and reasonably competitive positions are ensured. Including the acquisition of comprehensive airworthiness data as an integral part of materials and structures research should pay great dividends in allowing early definition of realistic regulations and certification requirements, thus expediting application of new materials and structural concepts.