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Results for “shocks”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Shock strength effects on separated flows in non-equilibrium chemically reacting air - Shock wave/boundary layer interaction

This work is part of a general study to examine the effects of nonequilibrium chemical reactions on hypersonic separated flows. In particular, the work presented is the first attempt to quantitatively predict the effects of impinging shock strength on the separation region in non-equilibrium chemically reacting air over a flat plate. Of special interest is the local heat transfer rate to the plate at the reattachment point. The effects of chemically non-equilibrium on the flow field are assessed by making direct comparisons to the results calculated assuming a calorically perfect flow. Chemical reactions are found to increase heat transfer rates, and this increase becomes significantly larger as Reynolds number increases.

Ballaro, Charles A.↗
NASA NTRS2018

Where are the Shocked Grains in the Hadean Zircon Record? Insights on the Preservation of Shocked Zircon and Their U-Pb Systematics

While the earliest history of many planetary bodies within the inner Solar System is dominated by intense bombardment, this record is missing from Earth due to active tectonics and erosion. Where-as rocks from the earliest history of Earth are absent, mineral relics, such as ancient detrital zircon concentrated in sediments within the Jack Hills, Narryer, Illara and Maynard Hills greenstone belts of the Yilgarn Craton in Western Australia preserve a record of this time.Shock in zircon: During shock deformation, resulting from hyper-velocity impact, zircon can be modified in crystallographically-controlled ways. This includes the development of planar and subplanar low-angle grain boundaries, the formation of mechanical twins, transformation to the high pressure polymorph reidite, development of polycrystalline microtexture, and dissociation to its dioxide constituents SiO2 and ZrO2.

Erickson, T. M.↗
NASA NTRS1990

Three-dimensional thermal-structural analysis of a swept cowl leading edge subjected to skewed shock-shock interference heating

A three-dimensional flux-based thermal analysis method has been developed and its capability is demonstrated by predicting the transient nonlinear temperature response of a swept cowl leading edge subjected to intense three-dimensional aerodynamic heating. The predicted temperature response from the transient thermal analysis is used in a linear elastic structural analysis to determine thermal stresses. Predicted thermal stresses are compared with those obtained from a two-dimensional analysis which represents conditions along the chord where maximum heating occurs. Results indicate a need for a three-dimensional analysis to predict accurately the leading edge thermal stress response.

Polesky, Sandra P.↗