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Kendall, J. M., Jr.

Publications and source records attributed to Kendall, J. M., Jr..

8 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Sensational spherical shells

Fluid-dynamic and capillary forces can be used to form nearly perfect, very small spherical shells when a liquid that can solidify is passed through an annular die to form an annular jet. Gravity and certain properties of even the most ideal materials, however, can cause slight asymmetries. The primary objective of the present work is the control of this shell formation process in earth laboratories rather than space microgravity, through the development of facilities and methods that minimize the deleterious effects of gravity, aerodynamic drag, and uncontrolled cooling. The spherical shells thus produced can be used in insulation, recyclable filter materials, fire retardants, explosives, heat transport slurries, shock-absorbing armor, and solid rocket motors.

Lee, M. C.↗
NASA NTRS1984

Low-Density High-Strength Foamed Materials

Molten bubbles of metal or plastic coalesce into strong, lightweight materials that look like solidified foam. Bubbles formed in compartment that receives molten material and compressed gas that fills bubbles. Compartment has matrix of nozzles. Leaving nozzles, bubbles fall into acoustic chamber and coalesce; then drop through funnel and are cast into desired shape by extrusion or molding. Materials used for construction, extruded into molds, sawed, nailed, and generally handled as wood.

Wang, T.↗
NASA NTRS1982

Method of forming frozen spheres in a force-free drop tower

Hollow glass spheres are shaped by the effects of surface tension acting on bubbles of glass in its molten state. A downwardly flowing stream of air accelerated at a one-G rate of acceleration is established through a drop bubbles on molten glass are introduced into the stream of air and frozen and as they are accelerated at a one-G rate of acceleration.

Kendall, J. M., Jr.↗
NASA NTRS1981

Drop tower with no aerodynamic drag

Cooling air accelerated to match velocity of falling object eliminates drag. 3 meter drop tower with suction fan and specific geometry causes air to accelerate downward at 1 g. Although cooling of molten material released from top is slow because surrounding air moves with it, drop remains nearly spherical.

Kendall, J. M., Jr.↗
NASA NTRS1981

Acoustic lens is gas-filled

Fluorocarbon gas contained by plastic membrane is effective lens for sound waves. In tests, lens substantially improved accuracy of sound "maps" of turbulent airflow. It could also be used to record sound intensity patterns in design of speakers, lecture halls, and auditoriums. Lens is fabricated by clamping together two membranes of thin plastic and filling enclosed space with fluorocarbon gas. Since speed of sound in gas is considerably less than in air, lens refracts and focuses sound waves, analogous to focusing light by glass lens. Focal length is adjusted simply by changing gas pressure, which changes lens curvature.

Kendall, J. M., Jr.↗
NASA NTRS1977

Acoustic imaging system

Tool detects noise sources by scanning sound "scene" and displaying relative location of noise-producing elements in area. System consists of ellipsoidal acoustic mirror and microphone and a display device.

Kendall, J. M., Jr.↗
NASA NTRS1977

Rocket calibration of the Nimbus 6 solar constant measurements

Total solar irradiance was observed simultaneously outside the earth's atmosphere by three types of absolute cavity radiometers and duplicates of four of the Nimbus 6 Earth Radiation Budget (ERB) solar channels in a June 1976 sounding rocket experiment. The preliminary average solar constant result from the cavity radiometers is 1367 Wm (-2) with an uncertainty of less than + or - 0.5% in S.I. units. The duplicate ERB channel 3 on the rocket gave a value of 1389 Wm (-2) which agreed exactly with the Nimbus 6 ERB channel 3 measurement made simultaneously with the rocket flight.

Duncan, C. H.↗