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Results for “Frost”

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 127 records · Page 7
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DOE OSTI2020

Efficiency Enhancing Anti-Frost Coatings for Heat Exchangers

As part of the Cyclotron Road program, the participant worked to develop geometric inorganic metamaterial coatings with functional surface energies that approached theoretical minimum. Most coating technologies chemically modify surfaces by applying a fluoropolymer to cause water to bead and roll off the surface, but the metamaterial coatings studied under this project were designed to modify local surface tension of a droplet, such that it pulls down on it at the bottom like a spring and as the droplet grows, the magnitude of the surface tension force increases to overwhelm droplet adhesion forces, causing the droplet to be repelled. These attributes make this technology ideally suited for heat transfer applications. This project’s coating experiments on evaporator coils inside an air conditioning unit demonstrated significant increases in energy efficiency.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1972

Identification of carbon dioxide frost on the Martian polar caps.

Spectra of the Martian south polar cap produced by the techniques of Fourier spectroscopy show 11 narrow features attributed to the composition of the polar cap. Through comparison with laboratory spectra, all 11 have been identified as solid CO2 absorptions.

Larson, H. P.↗
NASA NTRS1976

Evaluation of ice and frost accumulation on the Space Shuttle external tank

Ice/frost formation on the Space Shuttle cryogenic propellant tanks presents a different problem from that of past launch vehicles. Lift off weight addition has been the primary concern on past launch vehicles. The primary ice/frost concern on the Shuttle vehicle is damage to the Orbiter Thermal Protection System due to ice/frost impact. The approach used to arrive at a solution to this unique Shuttle problem is presented. The launch vehicle configuration selected and its limitations are described, along with contingency ground support equipment.

Rhodes, R. E.↗
NASA NTRS1978

Mars - Remote spectral identification of H2O frost and mineral hydrate

A reflectance spectrum (0.62-2.6 microns) of Mars (integral disk) is obtained using a newly developed IR spectrometer at the 2.25 m telescope on Mauna Kea, Hawaii. Details of the instrument, observations, and data reduction are presented. Several distinct absorption features are evident that were apparently caused by H2O, but the positions and intensities of the features are quite unusual. In summary, the regolith is probably not as desiccated and dehydrated as the full disk reflectance spectrum and Viking soil analyses would suggest. The surface materials become desiccated and dehydrated as a result of solar UV effects and because of the relative adsorption and desorption rates during the strong diurnal cycling. There may be significant amounts of H2O at depth, and in the Solis Lacus region the H2O reservoir may extend to within a few centimeters of the surface. The Solis Lacus region may therefore be an important target for future Mars landing or sample return mission.

Huguenin, R. L.↗
NASA NTRS1981

Application of Satellite Frost Forecast Technology to Other Parts of the United States Phase II: Introduction

The history and status of University of Michigan and University of Pennsylvania involvement in determining if P-model for front prediction used in Florida is applicable to those geographic locations is reviewed. The possibility of using the S-model to develop a satellite front forecast system that can recall the distribution of temperatures during previous freezes from a particular area and bring that cold climate climatology to bear on present forecasts is discussed as well as a proposed GOES satellite downlink system to sectionalize the data used in Florida.

Source record↗
NASA NTRS1983

Frost grain size metamorphism - Implications for remote sensing of planetary surfaces

The effective grain size of a material on a planetary surface affects the strength of absorption features observed in the reflectance of a particulate surface. In the case of a planetary surface containing volatile ices, the absorption characteristics can change in connection with processes leading to a change in the grain size of the material. The present investigation is concerned with an evaluation regarding the occurrence of such processes and the implications for remote sensing applications. It is found that quantitative modeling of the kinetics of grain growth and destruction by thermal and nonthermal processes can provide a means to reconcile apparent optical paths in the volatile portions of planetary surfaces with the physical history of those surfaces. Attention is also given to conditions in the case of the Pluto/Triton system, Uranus and Saturnian satellites, and the Galilean system.

Clark, R. N.↗