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Miller, J. L.

Publications and source records attributed to Miller, J. L..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Preliminary evaluation of hybrid titanium composite laminates

In this study, the mechanical response of hybrid titanium composite laminates (HTCL) was evaluated at room and elevated temperatures. Also, the use of an elastic-plastic laminate analysis program for predicting the tensile response from constituent properties was verified. The improvement in mechanical properties achieved by the laminates was assessed by comparing the results of static strength and constant amplitude fatigue tests to those for monolithic titanium sheet. Two HTCL were fabricated with different fiber volume fractions, resin layer thicknesses, and resins. One panel was thicker and was more poorly bonded in comparison to other. Consequently, the former had a lower tensile strength, while fewer cracks grew in this panel and at a slower rate. Both panels showed an improvement in fatigue life of almost two orders of magnitude. The model predictions were also in good agreement with the experimental results for both HTCL panels.

Miller, J. L.↗
NASA NTRS1983

Electric power - Looking at regenerative systems

Photovoltaic solar array technology dominates NASA space station planning for the late 1980s, although the reduction of fabrication costs and the extension of service life for such arrays remain essential goals for research and development. Attention is given to concentrator arrays, in which highly reflective surfaces concentrate solar energy onto the solar cells. Two types of concentrator arrays are under consideration: one with a low geometric concentration ratio which after reflector losses can produce about 5 suns at the cell surface, and the other with a Cassegrainian concentrator that produces a flux level of 100 suns on the cell surface. Costs are reduced from the $300/W for planar arrays to $250/W and as little as $100/W, respectively, in 1982 dollars. The storage of electrical energy by means of novel battery systems is also considered.

Miller, J. L.↗
NASA NTRS1982

The swing to concentrator arrays

Objectives and progress in both low concentration ratio (6 to 10) and high concentration ratio ( 100) array developments are summarized. Problems encountered include: thermal control, maldistribution of concentrated sunlight, current busing, and optical surface degradation. The potential advantages over planar arrays are an order of magnitude reduction in per unit cost of power plus increased immunity to radiation damage.

Miller, J. L.↗
NASA NTRS1977

Space power technology applied to the energy problem

A solution to the energy problem is suggested through the technology of photovoltaic electrolysis of water to generate hydrogen. Efficient solar devices are discussed in relation to available solar energy, and photovoltaic energy cost. It is concluded that photovoltaic electrolytic generation of hydrogen will be economically feasible in 1985.

Miller, J. L.↗
NASA NTRS1972

Solar cell dark I-V characteristics and their applications.

This paper presents the preliminary results of studies conducted to evaluate the feasibility of and to generate techniques for the use of dark forward current-voltage characteristics in the checkout of the Apollo Telescope Mount Solar Array. Methods for the determination of lumped series resistance and prediction of the illuminated I-V curve using the dark characteristics are also presented. The paper addresses itself primarily to the generation of a valid performance testing and flight readiness checkout technique using the forward characteristics of the solar cell.

Imamura, M. S.↗