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Search Publications by: Aaron Johnson (Fed)

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Displaying 51 - 75 of 107

Greenhouse Gas Emissions and Dispersion #2. Comparison of FDS Predictions with Gas Velocity Measurements in the Exhaust Duct of a Stationary Source

April 25, 2013
Author(s)
Kuldeep R. Prasad, Kevin Li, Elizabeth F. Moore, Rodney A. Bryant, Aaron N. Johnson, James R. Whetstone
The burning of fossil fuels remains a major source of greenhouse gases responsible for global warming and climate change. In order to reduce greenhouse gas emissions, it is imperative to develop a capability to accurately measure these emissions from point

Improved Nozzle Manifold for Gas Flow Calibrations

June 20, 2012
Author(s)
Aaron N. Johnson, Chunhui Li, John D. Wright, Gina M. Kline, Christopher J. Crowley
We developed a new nozzle manifold that reduced the uncertainty of flow calibrations from 0.09 % to as low as 0.074 % for flows of air up to 0.84 kg/s (43 000 L/min at reference conditions of 101.325 kPa and 293.15 K). The nozzle manifold also reduces the

Extended Lee model for the turbine meter & calibrations with surrogate fluids

May 1, 2012
Author(s)
Jodie G. Pope, John D. Wright, Aaron N. Johnson, Michael R. Moldover
We developed a physical model termed the “extended Lee model” for calibrating turbine meters to account for 1) fluid drag on the rotor, 2) bearing static drag and 3) bearing viscous drag. We tested the extended Lee model using a dual rotor, 2.5 cm diameter

Bilateral Comparison between NIST and PTB for Flows of High Pressure Natural Gas

April 6, 2012
Author(s)
Aaron N. Johnson, B Mickan, H. Toebben, Tom Kegel
In 2009 NIST developed a U.S. national flow standard to provide traceability for flow meters used for custody transfer of pipeline quality natural gas. NIST disseminates the SI unit of flow by calibrating a customer flow meter against a parallel array of

Comparison of Gas Velocity Measurements and CFD Predictions in the Exhaust Duct of a Stationary Source

July 13, 2011
Author(s)
Rodney A. Bryant, Olatunde B. Sanni, Elizabeth F. Moore, Robert P. Borthwick, Marco G. Fernandez, Iosif I. Shinder, Jiann C. Yang, Aaron N. Johnson
Two series of independent flow measurements were conducted for cross validation of flow velocity in the exhaust duct of the NIST Large Fire Laboratory. In the first series, two pressure measurement probe types, an S probe and a 3-D probe, were used to

Bilateral Comparison Confirms NIMs and NISTs Gas Flow Capabilities

October 15, 2010
Author(s)
Aaron N. Johnson, CHUNHUI LI
The bilateral comparison between NIM and NIST for gas flow was conducted from June 2008 to October 2009. Two critical flow venturis (CFVs) with nominal throat diameters of 10 mm and 20 mm, respectively, were selected as transfer standards. The CFVs were

Gas Flowmeter Calibrations With the 26 m 3 PVTt Standard

November 25, 2009
Author(s)
Aaron N. Johnson, John D. Wright
This document describes NIST s 26 m3 pressure, volume, temperature, and time (PVTt) primary flow standard. This standard is used to calibrate gas flow meters over a range extending from 200 standard L/min to 77,000 standard L/min where the reference

NIST Calibration Services for Liquid Volume

November 24, 2009
Author(s)
Vern E. Bean, Pedro I. Espina, John D. Wright, J F. Houser, Sherry D. Sheckels, Aaron N. Johnson
NIST provides calibration services for metal volume provers for liquid volumes from 4 L to 7600 L using gravimetric and volumetric methods. This document describes the procedures and methods of calculation used in the calibration service. The covered

Gas Flowmeter Calibrations With the Working Gas Flow Standard

November 23, 2009
Author(s)
John D. Wright, Jean-Phillipe Kayl, Aaron N. Johnson, Gina M. Kline
The Working Gas Flow Standard (WGFS) uses critical venturis, critical nozzles, or laminar flowmeters as working standards to calibrate customer flowmeters. The working standards are periodically calibrated with primary standards: the 34 L, 677 L, or 26 m3