Hypersonic airframe structures: Technology needs and flight test requirements

Hypersonic vehicles, that may be produced by the year 2000, were identified. Candidate thermal/structural concepts that merit consideration for these vehicles were described. The current status of analytical methods, materials, manufacturing techniques, and conceptual developments pertaining to these concepts were reviewed. Guidelines establishing meaningful technology goals were defined and twenty-eight specific technology needs were identified. The extent to which these technology needs can be satisfied, using existing capabilities and facilities without the benefit of a hypersonic research aircraft, was assessed. The role that a research aircraft can fill in advancing this technology was discussed and a flight test program was outlined. Research aircraft thermal/structural design philosophy was also discussed. Programs, integrating technology advancements with the projected vehicle needs, were presented. Program options were provided to reflect various scheduling and cost possibilities

Research in particles and fields

Cosmic rays and astrophysical plasmas, NASA spacecraft experiment activities, and gamma rays are discussed

Research in particles and fields

The astrophysical aspects of cosmic and gamma rays and the radiation environment of the Earth and other planets investigated by means of energetic particle detector systems flown on spacecraft and balloons are discussed. The theory of particles and fields in space is also addressed with particular emphasis on models of Saturn's magnetic field

RANDOM MATRIX THEORY APPROACH TO THE INTENSITY DISTRIBUTIONS OF WAVES PROPAGATING IN A RANDOM MEDIUM

Statistical properties of coherent radiation propagating in a quasi - 1D random media is studied in the framework of random matrix theory. Distribution functions for the total transmission coefficient and the angular transmission coefficient are obtained.Comment: 8 pages, latex, no figures. Submitted to Phys.Rev.

An Improved Prediction Method for Noise Generated by Conventional Profile Coaxial Jets

A semiempirical model for predicting the noise generated by conventional velocity profile jets exhausting from coaxial nozzles is presented and compared with small scale static and simulated flight data. Improvements to the basic circular jet noise prediction are developed which improve the accuracy, especially at high jet velocity and near the jet axis

Research in particles and fields

The astrophysical aspects of cosmic radiation and the radiation and electromagnetic field environment of the Earth and other planets are investigated. Energetic particle and photon detector systems flown on spacecraft and balloons are used. Galactic, solar, interplanetary, and planetary energetic particles and plasmas are also studied with emphasis on precision measurements with high resolution in charge, mass, and energy

Phase-space correlations of chaotic eigenstates

It is shown that the Husimi representations of chaotic eigenstates are strongly correlated along classical trajectories. These correlations extend across the whole system size and, unlike the corresponding eigenfunction correlations in configuration space, they persist in the semiclassical limit. A quantitative theory is developed on the basis of Gaussian wavepacket dynamics and random-matrix arguments. The role of symmetries is discussed for the example of time-reversal invariance.Comment: Published version with minor corrections to version

Heat pipes for wing leading edges of hypersonic vehicles

Wing leading edge heat pipes were conceptually designed for three types of vehicle: an entry research vehicle, aero-space plane, and advanced shuttle. A full scale, internally instrumented sodium/Hastelloy X heat pipe was successfully designed and fabricated for the advanced shuttle application. The 69.4 inch long heat pipe reduces peak leading edge temperatures from 3500 F to 1800 F. It is internally instrumented with thermocouples and pressure transducers to measure sodium vapor qualities. Large thermal gradients and consequently large thermal stresses, which have the potential of limiting heat pipe life, were predicted to occur during startup. A test stand and test plan were developed for subsequent testing of this heat pipe. Heat pipe manufacturing technology was advanced during this program, including the development of an innovative technique for wick installation