Wandel, Andrew P. 
ORCID: https://orcid.org/0000-0002-7677-7129
(2013)
Conditional dissipation of scalars in homogeneous turbulence: closure for MMC modelling.
Combustion Theory and Modelling, 17 (4).
pp. 707-748.
ISSN 1364-7830
Abstract
While the mean and unconditional variance are to be predicted well by any reasonable turbulent combustion model, these are generally not sufficient for the accurate modelling of complex phenomena such as extinction/reignition. An additional criterion has been recently introduced: accurate modelling of the dissipation timescales associated with fluctuations of scalars about their conditional mean (conditional dissipation timescales). Analysis of Direct Numerical Simulation (DNS) results for a passive scalar shows that the conditional dissipation timescale is of the order of the integral timescale and smaller than the unconditional dissipation timescale. A model is proposed: the conditional dissipation timescale is proportional to the integral timescale. This model is used in Multiple Mapping Conditioning (MMC) modelling for a passive scalar case and a reactive scalar case, comparing to DNS results for both. The results show that this model improves the accuracy of MMC predictions so as to match the DNS results more closely using a relatively-coarse spatial resolution compared to other turbulent combustion models.
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| Item Type: | Article (Commonwealth Reporting Category C) |
|---|---|
| Refereed: | Yes |
| Item Status: | Live Archive |
| Additional Information: | Permanent restricted access to Published version due to publisher copyright policy. |
| Faculty/School / Institute/Centre: | Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021) |
| Faculty/School / Institute/Centre: | Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021) |
| Date Deposited: | 18 Jul 2013 23:47 |
| Last Modified: | 15 Jan 2015 04:33 |
| Uncontrolled Keywords: | conditional timescale; direct numerical simulations; multiple mapping conditioning; scalar dissipation; turbulent combustion |
| Fields of Research (2008): | 09 Engineering > 0904 Chemical Engineering > 090405 Non-automotive Combustion and Fuel Engineering (incl. Alternative/Renewable Fuels) 09 Engineering > 0915 Interdisciplinary Engineering > 091508 Turbulent Flows 09 Engineering > 0904 Chemical Engineering > 090407 Process Control and Simulation |
| Fields of Research (2020): | 40 ENGINEERING > 4004 Chemical engineering > 400402 Chemical and thermal processes in energy and combustion 40 ENGINEERING > 4012 Fluid mechanics and thermal engineering > 401213 Turbulent flows 40 ENGINEERING > 4004 Chemical engineering > 400407 Process control and simulation |
| Socio-Economic Objectives (2008): | E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering |
| Identification Number or DOI: | https://doi.org/10.1080/13647830.2013.794391 |
| URI: | http://eprints.usq.edu.au/id/eprint/23769 |
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