Large eddy simulation of soot evolution in turbulent reacting flows
Abstract/Contents
- Abstract
- Soot particles are nanoparticles consisting primarily of carbon that are formed during the combustion of fuel-rich mixtures. Due to environmental and health concerns, soot emissions from combustion systems are tightly regulated, and this regulation will only become stricter in the future. To enable the design of the next generation of low-emission combustion systems, predictive numerical simulations will be required. However, soot is a particularly difficult modeling problem due to the needs for high-fidelity models for soot itself in addition to chemistry and turbulence. This dissertation seeks to develop an integrated modeling framework based on Large Eddy Simulation (LES) for soot evolution in turbulent reacting flows. The final objective is the demonstration and evaluation of the model in an actual aircraft combustor. In order to enable these high-fidelity simulations, three component models have been developed. First, a detailed soot model is developed within the framework of the Method of Moments. New models for soot aggregation and fragmentation are proposed, and closure of the moment source terms is achieved with the Hybrid Method of Moments (HMOM), an accurate yet computationally efficient method. Second, a new turbulent combustion model is developed based on the Radiation Flamelet/Progress Variable (RFPV) model that can account for the removal of precursors from the gas-phase to form soot particles. Third, a subfilter PDF model is developed to account for the unresolved small-scale interactions between soot, turbulence, and chemistry. The subfilter PDF approach is validated a priori against a recent DNS database of soot evolution in a turbulent nonpremixed flame. The integrated modeling approach is then validated against experimental measurements in two laboratory-scale turbulent nonpremixed flames: a natural gas piloted jet flame and an ethylene bluff body flame. Differences in soot evolution due to the differences in the large-scale mixing in the two flames are discussed. The validated model is then applied to the simulation of a Pratt & Whitney aircraft combustor. Two operating points are simulated to assess the ability of the integrated model to reproduce quantitative trends in soot emissions.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Mueller, Michael Edward |
|---|---|
| Associated with | Stanford University, Department of Mechanical Engineering |
| Primary advisor | Pitsch, Heinz |
| Thesis advisor | Pitsch, Heinz |
| Thesis advisor | Bowman, Craig T. (Craig Thomas), 1939- |
| Thesis advisor | Moin, Parviz |
| Advisor | Bowman, Craig T. (Craig Thomas), 1939- |
| Advisor | Moin, Parviz |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Michael E. Mueller. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Michael Edward Mueller
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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