Engineering topics

Onstott, Joseph W.

Publications and source records attributed to Onstott, Joseph W..

3 records

NASA NTRS1995

Fatigue-Arrestor Bolts

Bolts that arrest (or, more precisely, retard) onset of fatigue cracking caused by inelastic strains developed. Specifically developed to be installed in flange holes of unrestrained rocket engine nozzle. Fanges sometimes used to bolt nozzle to test stand; however, when rocket engine operated without this restraint, region around bolt holes experience severe inelastic strains causing fatigue cracking. Interference fits introduce compressive preloads that retard fatigue by reducing ranges of strains. Principle of these fatigue-arrestor bolts also applicable to holes in plates made of other materials and/or used for different purposes.

Onstott, Joseph W.↗

NASA NTRS1992

Porous Barrier To Flow Of Hot Gas

Porous, ropelike barrier prevents recirculating flow of hot, hydrogen-rich steam from reaching nickel-alloy bellows seal located deep in gap in wall of combustion chamber. Proven successful protecting bellows seal at different values of protrusion of coolant tubes giving rise to recirculating hot flow. Similar barriers help block deleterious recirculating flow of hot gases in other combustion chambers such as furnaces and turbomachines.

Onstott, Joseph W.↗

NASA NTRS1989

High temperature insulation barrier composite

A composite material suitable for providing insulation for the nozzle structure of the Space Shuttle and other similar surfaces is disclosed. The composite layer is comprised of an outer skin layer of nickel chromium and an interleaved inner region comprising a top layer of nickel chromium foil which acts as a primary convective shield. There are at least two layers of alumina batting adjacent to the layers of silicon carbide fabric. An additional layer of nickel chromium foil is used as a secondary convective shield. The composite is particularly advantageous for use as nozzle insulation because of its ability to withstand high reentry temperatures, its flexibility, oxidation resistance, low conductivity, and light weight.

Onstott, Joseph W.↗