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Results for “Measurement_method”

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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1967

Flow measurement. II.

Cryogenic fluid mass flow measurement methods, noting flow meter calibration

FLOW MEASUREMENT↗
NASA NTRS1972

An investigation of geometry and noise corrections to San Marco-C neutral atmospheric composition experiment data

The problem of the calculation of ambient densities from San Marco-C neutral atmospheric composition experiment data is considered. A brief description is given of the data measurement method, followed by a description of both the theoretical and experimental data curves. Geometry, electrometer distortions, and noise effects are then studied in terms of their effects on the ideal data form. From these considerations two data reduction methods are evolved. The first is an iterative integration technique that exploits the symmetry of the experimental data about the minimum angle of attack. For the analysis of geometry effects, a second method using interval averaging was developed and studied.

Curtis, S. A.↗
NASA NTRS1940

Pressure and temperature measurement in supercharger investigations

With the further development of the supercharger, requirements with regard to measuring accuracy increase while at the same time the conditions under which the measurements must be carried out become more difficult. The present paper is a contribution toward the improvement and refinement of the measuring methods. For pressure measurements some suggestions are made with regard to design and location of the measuring stations. The question of temperature measurement in rapid air flow is discussed, new instruments for the direct measurement of the temperature in the rapid airstream are described and the results obtained with the various instruments presented.

Franz, A↗
NASA NTRS1939

Experiments on a Slotted Wing

The results of pressure distribution measurements that were made on a model wing section of a Fieseler F 5 R type airplane are presented. Comparison of those model tests with the corresponding flight tests indicates the limitations and also the advantages of wind tunnel investigations, the advantages being particularly that through the variety of measuring methods employed the more complicated flow conditions may also be clarified. A fact brought out in these tests is that even in the case of "well rounded" slots it is possible for a vortex to be set up at the slot entrance and this vortex is responsible for certain irregularities in the pressure distribution and in the efficiency of the slot.

Ruden, P↗
NASA NTRS1944

Researches on the Piston Ring

In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and experiments conducted by the author, on this subject will be fully described in the following paragraphs.

Ehihara, Keikiti↗
DOE OSTI2025

Brillouin Sensing with PCA, and PCA-Based Neural Networks for Efficient Temperature Monitoring

This work explores peak estimation techniques in Brillouin Optical Time Domain Analysis (BOTDA), emphasizing both accuracy and efficiency. Euclidean distance measurement method is applied to principal components derived from Brillouin Gain Spectrum data. It offers a major speed advantage being 180 170 times faster than traditional curve fitting methods such as Lorentzian curve fitting, while maintaining similar accuracy. Additionally, a PCA- based neural network model shows significant reduction of peak estimation time compared to Lorentzian fitting. Results show Brillouin frequency shift errors lie under 0.75 MHz in both Euclidean distance-based and neural network-based methods, both of which utilize PCA components. For large data sets and long length fibers, PCA- assisted neural network for peak estimation would be an efficient solution.

Distributed optical fiber sensing↗