Millimeter wave rheometry: theory and experiment

Chun, Jaehun; McCloy, John S.; Crum, Jarrod V.; Sundaram, S. K.

doi:10.1007/s00397-010-0522-1

Cited by 3 publications

(4 citation statements)

References 13 publications

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“…In our system, a time-dependent thickness of the fluid flowing by gravity causes interference between the front and back surfaces of the flowing fluid, rather than between the surface of the highly reflective melt and the MMW receiver input as demonstrated previously. The theoretical basis for determining the viscosity from the interferometric fringes of a fluid flowing has been recently described [9]. The improved geometry demonstrates the potential of applying this measurement for industrial gasifiers.…”

Section: Millimeter-wave Interferometrymentioning

confidence: 99%

“…The mixing of the reflected LO with the LO causes interference fringes in the "video" channels that make possible the measurement of volume expansion, level change, and viscosity [5,9]. At normal incidence, the signal reflects off the object of interest, returns via the same channel through the horn and into a mixer where it is converted to a direct current (DC) signal ("video"), is routed through a lock-in amplifier to detect the chopper-modulated part, then monitored by a computer through a general purpose interface bus (GPIB).…”

Section: Millimeter-wave Radiometrymentioning

confidence: 99%

“…1) [8,9]. The heterodyne receiver system consists of four channels: two receiver channels and two "video" channels.…”

Section: Millimeter-wave Radiometrymentioning

confidence: 99%

See 2 more Smart Citations

High Temperature Millimeter Wave Radiometric and Interferometric Measurements of Slag-Refractory Interaction for Application to Coal Gasifiers

McCloy

Crum

Sundaram

et al. 2011

J Infrared Milli Terahz Waves

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Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments such as in slagging coal gasifiers, where sensors have been identified as a key enabling technology need for process optimization. We present a dual-channel MMW heterodyne radiometer with active interferometric capability that allows simultaneous measurements of sample temperature, emissivity, and flow dynamics. Interferometric capability at 137 GHz is supplied via a probe signal originating from a local oscillator allowing monitoring of sample dynamics such as volume expansion and thickness change. This capability has been used to monitor characteristic behavior between refractories and slag such as slag infiltration, slag melting, viscous flow, foaming, and crucible corrosion by the molten slag. These results show the promise of the MMW system for extracting process parameters from operating slagging coal gasifiers, providing valuable information for process efficiency, control, and increased productivity.

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Section: Millimeter-wave Interferometrymentioning

confidence: 99%

Section: Millimeter-wave Radiometrymentioning

confidence: 99%

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High Temperature Millimeter Wave Radiometric and Interferometric Measurements of Slag-Refractory Interaction for Application to Coal Gasifiers

McCloy

Crum

Sundaram

et al. 2011

J Infrared Milli Terahz Waves

Self Cite

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show abstract

“…Interferometric capabilities derive from a narrowband local oscillator (LO) probe at 137 GHz leaked from the heterodyne receiver, and the mixed probe/ return "video" channels allow measurement of volume expansion, level change, and viscosity. 11,12 The viscosity is determined by measuring the velocity of flow of the melt into a waveguide and knowing the density of the melt.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry

McCloy

Sundaram

Matyáš

et al. 2011

Review of Scientific Instruments

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Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments (high temperature, pressure, and corrosive environments). The state-of-the-art dual channel MMW passive radiometer with active interferometric capabilities at 137 GHz described here allows for radiometric measurements of sample temperature and emissivity up to at least 1600 °C with simultaneous measurement of sample surface dynamics. These capabilities have been used to demonstrate dynamic measurement of melting of powders of simulated lunar regolith and static measurement of emissivity of solid samples. The paper presents the theoretical background and basis for the dual-receiver system, describes the hardware in detail, and demonstrates the data analysis. Post-experiment analysis of emissivity versus temperature allows further extraction from the radiometric data of millimeter wave viewing beam coupling factors, which provide corroboratory evidence to the interferometric data of the process dynamics observed. These results show the promise of the MMW system for extracting quantitative and qualitative process parameters for industrial processes and access to real-time dynamics of materials behavior in extreme environments.

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In-line detection of salt formation during vitrification using millimeter wave radiometry and interferometry

Bussey,

Wells,

Smith-Gray

et al. 2025

Measurement

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Millimeter wave rheometry: theory and experiment

Cited by 3 publications

References 13 publications

High Temperature Millimeter Wave Radiometric and Interferometric Measurements of Slag-Refractory Interaction for Application to Coal Gasifiers

High Temperature Millimeter Wave Radiometric and Interferometric Measurements of Slag-Refractory Interaction for Application to Coal Gasifiers

Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry

In-line detection of salt formation during vitrification using millimeter wave radiometry and interferometry

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