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Title: Boundary-Layer Model to Predict Chemically Reacting Flow within Heated, High-Speed, Microtubular Reactors

Chen nozzle experiments are used to study the early–stage unimolecular decomposition of larger molecules and, sometimes, the following chemistry. The nozzle itself is typically a small–diameter (order millimeter), short (order 20–50 mm), heated (order 1700 K) tube (nozzle) that exhausts into a vacuum chamber where a variety of diagnostics may be used to measure gas–phase composition. Under typical operating conditions, the velocities are high and the exhaust flow is near sonic. Quantitatively interpreting the measurements requires a model for flow within the nozzle that is coupled with reaction kinetics simulations. The present model shows that the flow can produce significant radial and axial variations in both the thermodynamic conditions and species concentrations. Thus, plug–flow models may not be appropriate. Results show that using He as a carrier gas produces much more plug–like flow than is the case with Ar as the carrier gas. As a result, the boundary–layer model provides a computationally efficient approach to modeling detailed chemical kinetics within Chen nozzles. Results are illustrated using acetaldehyde decomposition kinetics.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [1]
  1. Colorado School of Mines, Golden, CO (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
International Journal of Chemical Kinetics
Additional Journal Information:
Journal Volume: 50; Journal Issue: 7; Journal ID: ISSN 0538-8066
Publisher:
Wiley
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; US Department of the Navy, Office of Naval Research (ONR)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Acetaldehyde decomposition; Boundary-layer model; CANTERA; Chen nozzle; Micro-tubular reactors
OSTI Identifier:
1460840

Weddle, Peter J., Karakaya, Canan, Zhu, Huayang, Sivaramakrishnan, Raghu, Prozument, Kirill, and Kee, Robert J.. Boundary-Layer Model to Predict Chemically Reacting Flow within Heated, High-Speed, Microtubular Reactors. United States: N. p., Web. doi:10.1002/kin.21173.
Weddle, Peter J., Karakaya, Canan, Zhu, Huayang, Sivaramakrishnan, Raghu, Prozument, Kirill, & Kee, Robert J.. Boundary-Layer Model to Predict Chemically Reacting Flow within Heated, High-Speed, Microtubular Reactors. United States. doi:10.1002/kin.21173.
Weddle, Peter J., Karakaya, Canan, Zhu, Huayang, Sivaramakrishnan, Raghu, Prozument, Kirill, and Kee, Robert J.. 2018. "Boundary-Layer Model to Predict Chemically Reacting Flow within Heated, High-Speed, Microtubular Reactors". United States. doi:10.1002/kin.21173.
@article{osti_1460840,
title = {Boundary-Layer Model to Predict Chemically Reacting Flow within Heated, High-Speed, Microtubular Reactors},
author = {Weddle, Peter J. and Karakaya, Canan and Zhu, Huayang and Sivaramakrishnan, Raghu and Prozument, Kirill and Kee, Robert J.},
abstractNote = {Chen nozzle experiments are used to study the early–stage unimolecular decomposition of larger molecules and, sometimes, the following chemistry. The nozzle itself is typically a small–diameter (order millimeter), short (order 20–50 mm), heated (order 1700 K) tube (nozzle) that exhausts into a vacuum chamber where a variety of diagnostics may be used to measure gas–phase composition. Under typical operating conditions, the velocities are high and the exhaust flow is near sonic. Quantitatively interpreting the measurements requires a model for flow within the nozzle that is coupled with reaction kinetics simulations. The present model shows that the flow can produce significant radial and axial variations in both the thermodynamic conditions and species concentrations. Thus, plug–flow models may not be appropriate. Results show that using He as a carrier gas produces much more plug–like flow than is the case with Ar as the carrier gas. As a result, the boundary–layer model provides a computationally efficient approach to modeling detailed chemical kinetics within Chen nozzles. Results are illustrated using acetaldehyde decomposition kinetics.},
doi = {10.1002/kin.21173},
journal = {International Journal of Chemical Kinetics},
number = 7,
volume = 50,
place = {United States},
year = {2018},
month = {4}
}