Solid Volume Fraction Measurement of Gas–Solid Two-Phase Flow Based on Terahertz Time-Domain Spectroscopy Technique: A Preliminary Study and Static Experimental Results

2009 ◽  
Vol 58 (5) ◽  
pp. 1585-1591 ◽  
Author(s):  
Yian Liu ◽  
Zhiyao Huang ◽  
Haifeng Ji ◽  
Haiqing Li
Keyword(s):  
Time Domain ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Phase Flow ◽  
Spectroscopy Technique ◽  
Terahertz Time Domain Spectroscopy ◽  
Two Phase ◽  
Time Domain Spectroscopy ◽  
Preliminary Study ◽  
Fraction Measurement

Reliable Evaluation of Oil–Water Two-Phase Flow Using a Method Based on Terahertz Time-Domain Spectroscopy

2017 ◽  
Vol 31 (3) ◽  
pp. 2765-2770 ◽  
Author(s):  
Yan Song ◽  
Xinyang Miao ◽  
Kun Zhao ◽  
Honglei Zhan ◽  
Chen Jiang ◽  
...  
Keyword(s):  
Time Domain ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Terahertz Time Domain Spectroscopy ◽  
Two Phase ◽  
Time Domain Spectroscopy ◽  
Oil Water

Soot Optical Properties in the Terahertz Spectra Domain

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Fei Wang ◽  
Ting Xu ◽  
Zhishen Qiang ◽  
Qunxing Huang ◽  
Dong Liu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Time Domain ◽  
Wavelength Region ◽  
Optical Methods ◽  
Optical Data ◽  
Refractive Indices ◽  
Spectroscopy Technique ◽  
Terahertz Time Domain Spectroscopy ◽  
Time Domain Spectroscopy ◽  
Combustion Diagnostics

For understanding and accurately modeling combustion, the important questions are what species are present in the flame, and the spatial distribution and temperature of these species. Traditional optical methods used only the electromagnetic waves in the wavelength region from the ultraviolet region up to the infrared. Terahertz time-domain spectroscopy technique can be used for the combustion research as a novel tool. However, for some sooty combustion environments, the strong absorption, spectral interference from soot scattering, and fluorescence from large molecules must be considered. The optical properties of soot in the terahertz domain are the main basic data for terahertz application. In this paper, the terahertz time-domain spectroscopy technique was used to study the optical properties of flame soot within 0.2–1.6 THz. The complex refractive indices of the soot were deduced by the fixed-point iteration method. In order to validate the results, the complex refractive indices of the soot from the four different fuel flames were deduced. It was found that the complex refractive indices in the terahertz domain of the soot from the different fuel flames are very close to each other. The comparisons of complex refractive indices between the visible–IR domain and the terahertz domain indicate that the value of absorption index in terahertz domain is smaller than in IR domain, which implies that the terahertz wave will penetrate the sooty flame with smaller absorption than the IR rays. The results can provide the basic optical data of flame soot for the application of terahertz time-domain spectroscopy technique in the optical combustion diagnostics and extend the optical combustion diagnostics application area.

Numerical Simulation of Modified Trailing Edge of Francis Turbine Stay Vane Based on Solid-Liquid Two-Phase Flow

2014 ◽  
Vol 700 ◽  
pp. 643-646
Author(s):  
Dong Wang ◽  
Si Qing Zhang ◽  
Yun Long Zhang
Keyword(s):  
Numerical Simulation ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Francis Turbine ◽  
Phase Flow ◽  
Oblique Angle ◽  
Trailing Edge ◽  
Two Phase ◽  
High Solid ◽  
Solid Liquid

In order to investigate the silt abrasion of modified trailing edge of stay vane in Francis turbine, the numerical simulation of trailing edge with different geometries were carried out based on the solid-liquid two-phase flow by means of Computation Fluid Dynamics. The results show that low solid volume fraction distributes on the chamfered surface of trailing edge, and high solid volume fraction distributes on the end of oblique surface. The smaller the modified angle is, the larger the distribution area of high solid volume fraction is, which show the trailing edge with smaller oblique angle may suffer from silt abrasion. Therefore, in order to solve the vibration caused by Karman vortex the trailing edge has to be sharpened, the oblique angle of trailing edge should not be too small. At end of trailing edge needs to ensure a certain thickness, especially the trailing edge near the lower ring can be thicker, which can meet the anti-abrasion requirements.

Detecting mouse glioma tissues with a terahertz time-domain spectroscopy technique

2021 ◽  
Author(s):  
Yuansen Guo ◽  
Shi Wang ◽  
Tunan Chen ◽  
Hua Zhang ◽  
Dandan Li ◽  
...  
Keyword(s):  
Time Domain ◽  
Spectroscopy Technique ◽  
Terahertz Time Domain Spectroscopy ◽  
Time Domain Spectroscopy ◽  
Mouse Glioma

Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS)

2018 ◽  
Vol 72 (6) ◽  
pp. 870-878
Author(s):  
Hang Wu ◽  
Shixiang Wu ◽  
Nansheng Qiu ◽  
Jian Chang ◽  
Rima Bao ◽  
...  
Keyword(s):  
Time Domain ◽  
Fission Track ◽  
Volume Fraction ◽  
Source Rocks ◽  
Volume Index ◽  
Hydrocarbon Generation ◽  
Terahertz Time Domain Spectroscopy ◽  
Time Domain Spectroscopy ◽  
Fission Tracks ◽  
Geological Conditions

Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by 238U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. In this study, on the basis of the ellipsoid configuration of tracks, the track volume fraction model (TVFM) is established and the fission-track volume index is proposed. Furthermore, terahertz time domain spectroscopy (THz-TDS) is used for the first time to identify the variation of the AFT annealing degree of Durango apatite particles heated at 20, 275, 300, 325, 450, and 500 ℃ for 10 h. The THz absorbance of the sample increases with the degree of annealing. In addition, the THz absorption index is exponentially related to annealing temperature and can be used to characterize the fission-track volume index. Terahertz time domain spectroscopy can be an ancillary technique for AFT thermochronological research. More work is urgently needed to extrapolate experimental data to geological conditions.

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