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Metrology

Flow metrology & rheology

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  • Published Date
Displaying 51 - 75 of 177

Flow fluctuations in wormlike micelle fluids

October 22, 2018
Author(s)
Paul NMN Salipante, Steven Meek, Steven D Hudson
We investigate the unstable flow of wormlike micelle solutions in pressure driven capillary flow, with a focus on the effect of entrance geometry on the fluid fluctuations. The flow is measured at different points in the capillary using particle image

Improving Measurement for Smokestack Emissions - Workshop Summary

September 21, 2018
Author(s)
Rodney A. Bryant, Aaron N. Johnson, John D. Wright, Tamae M. Wong, James R. Whetstone, Michael R. Moldover, Iosif I. Shinder, Scott Swiggard, Chris Gunning, David Elam, Tom Martz, Eric Harman, David Nuckols, Liang Zhang, Woong Kang, Salvator Vigil
The complex flow conditions inherent in power plant smokestacks make accurate flow measurements challenging, which in turn limits the accuracy of hazardous emissions measurements. While stack composition measurements are assessed daily via comparison to a

Characterization of Five-Hole Probes used for Flow Measurement in Stack Emission Testing

May 16, 2018
Author(s)
Iosif Isaakovich Shinder, Aaron Johnson, Michael R. Moldover, James Filla, Vladimir Khromchenko
We report progress towards the goal of reducing the errors in industrial smokestack flow measurements to 1 % by replacing S-probes with calibrated 3-D probes (i.e., probes that measure 3 components of velocity). NIST calibrated a commercially-manufactured

Progress Towards Accurate Monitoring of Flue Gas Emissions

May 16, 2018
Author(s)
Aaron Johnson, Iosif Isaakovich Shinder, Michael R. Moldover, Joey Boyd, James Filla
The amounts of CO2 and other pollutants emitted by a coal-fired power plant are measured using a continuous emissions monitoring system (CEMS) permanently installed in the exhaust smokestack. The pollutant flux is the product of the pollutant's

Characterizing Gas-Collection Volumes with Acoustic and Microwave Resonances

March 27, 2018
Author(s)
Jodie Gail Pope, Keith A. Gillis, Michael R. Moldover, J B. Mehl, Eric Harman
We characterized a 1.8 m3, nearly-spherical, steel shell at pressures up to 7 MPa for use as a gas flow standard. For pressure, volume, temperature, and time measurements, the shell's cavity will collect gas; for blow-down measurements, the shell will be a

Errors in Rate of Rise Gas Flow Measurements from Flow Work

March 20, 2018
Author(s)
John D. Wright, Aaron Johnson, Gina Kline, Michael R. Moldover
The rate of rise (RoR) method measures the time rate of change of the mass of gas in a collection volume as it is filled via a flow meter under test. The mass of gas is calculated from time-stamped pressure and temperature data gathered from the known

Integrated Optical Waveguides for in situ Microflow Measurements

October 15, 2017
Author(s)
James R. Hands, Gregory A. Cooksey
The need for quantitative microscale chemical and biological experiments has resulted in the increasing utilization of microfluidics with integrated sensors, allowing such architectures to synergistically enhance function and performance [1]. This work

Viscosity Measurements of R32 and R410A to 350 MPa

August 1, 2017
Author(s)
Arno D. Laesecke, Scott Bair
Viscosity measurements were performed with a falling cylinder viscometer on difluoromethane (R32) and the refrigerant blend R410A (R32+R125 with 50 % by mass) at the temperatures 313.15 K, 348.15 K, and 393.15 K with pressures to 350 MPa. The measurement

Microparticle tracking velocimetry as a tool for microfluidic flow measurements

June 7, 2017
Author(s)
Paul NMN Salipante, Steven D Hudson, James W. Schmidt, John D. Wright
The accurate measurement of flows in microfluidic channels is important for commercial and research applications. We compare the accuracy of flow measurement techniques over a wide range flows. Flow measurements made using holographic microparticle

Reference Correlation for the Viscosity of Carbon Dioxide

March 21, 2017
Author(s)
Arno D. Laesecke, Chris D. Muzny
A comprehensive database of experimental and computed data for the viscosity of carbon dioxide (CO2) was compiled and a new reference correlation was developed. Literature results based on an ab initio potential energy surface were the foundation of the

Jetting of a shear banding fluid in a rectangular duct

March 14, 2017
Author(s)
Paul NMN Salipante, Charles A. Little, Steven D Hudson
We report on a jetting flow instability of shear banding worm-like micelle (WLM) solutions in microfluidic channels with rectangular cross-sections over an intermediate volumetric flow regime. Particle tracking methods are used to measure the three

Molecular Dynamics Simulation of Trimer Self-Assembly Under Shear

March 6, 2017
Author(s)
Raymond D. Mountain, Harold Hatch, Vincent K. Shen
The self-assembly of patchy trimer particles with one attractive bead and two repulsive beads is investigated with nonequilibrium molecular dynamics simulations in the presence of a velocity gradient, as would be produced by the application of a shear

Detecting leaks in gas-filled pressure vessels using acoustic resonances

May 6, 2016
Author(s)
Keith A. Gillis, Michael R. Moldover, James B. Mehl
We demonstrate that a leak from a large, unthermostatted pressure vessel into ambient air can be detected an order of magnitude more effectively by measuring the time dependence of the ratio p/f 2 than by measuring the ratio p/T. Here f is the resonance

In-Situ Metrology to Characterize Water Vapor Delivery during Atomic Layer Deposition

May 2, 2016
Author(s)
Tariq Ahmido, William A. Kimes, Brent A. Sperling, Joseph T. Hodges, James E. Maslar
Water is often employed as the oxygen source in metal oxide atomic layer deposition (ALD) processes. It has been reported that variations in the amount of water delivered during metal oxide ALD can impact the oxide film properties. Hence, one contribution

Reclamation-NIST Exploratory Research Symposium Summary Report

April 6, 2016
Author(s)
Nicholas Barbosa, Jessica Torrey
The Reclamation-NIST Exploratory Research Symposium was held on August 4-5, 2015, at the Reclamation Denver Federal Center facility in Lakewood, CO, and the NIST facility in Boulder, CO. Staff from the Bureau of Reclamation and the National Institute of

A New Experiment for Determining Evaporation and Condensation Coefficients of Cryogenic Propellants

March 1, 2016
Author(s)
Kishan Bellur, E F. Medici, M Kulshreshtha, V Konduru, D Tyrewala, A Tamilarasan, J McQuillen, Juscelino Leao, Daniel S. Hussey, David L. Jacobson, Julia Scherschligt, J Hermanson, C Choi, J Allen
Passive and active technologies have been used to control propellant boil-o , but the current state of understanding of cryogenic evaporation and condensation in microgravity is insucient for designing large cryogenic depots critical to the long-term

Measuring collected gas with microwave and acoustic resonances

April 23, 2015
Author(s)
Keith A. Gillis, James W. Schmidt, Michael R. Moldover, James B. Mehl
With calibrations of large flow meters in mind, we established the feasibility of determining the mass M of argon gas contained within a 0.3 m 3 commercially manufactured pressure vessel ("tank") with a relative standard uncertainty of u r(M) = 0.0016 at 0
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