Constant volume n-Heptane autoignition using One-Dimensional Turbulence
| Autor: | Heiko Schmidt, A M Juan Medina, Fabian Mauss, Zoltan Jozefik |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Hull speed Field (physics) Turbulence General Chemical Engineering General Physics and Astronomy Energy Engineering and Power Technology Autoignition temperature 02 engineering and technology General Chemistry Mechanics 01 natural sciences 010305 fluids & plasmas Fuel Technology 020401 chemical engineering Volume (thermodynamics) 0103 physical sciences Dispersion (optics) 0204 chemical engineering Constant (mathematics) Scalar field |
| Zdroj: | Combustion and Flame. 190:388-401 |
| ISSN: | 0010-2180 |
| DOI: | 10.1016/j.combustflame.2017.12.015 |
| Popis: | Constant volume premixed lean n-Heptane/air autoignition at high pressure is investigated using the One-Dimensional Turbulence (ODT) model. The configuration consists of a 1D fixed volume domain with a prescribed velocity spectrum and temperature fluctuations superimposed on an initial uniformly elevated scalar field. The sensitivity of the heat release rate and pressure evolution to the initial temperature distribution is studied by imposing different initial temperature fields while holding the mean, RMS and integral length scale of the field constant. Three detailed chemical mechanisms are employed for the prediction of autoignition and heat release rate. To mitigate the high computational cost associated with the calculation of the chemical source terms in the stiff complex mechanisms, an approach based on the Strang-Splitting method is presented. Finally, a study of the ODT model uncertainty is carried out. For validation, ODT results are compared to 2D DNS data from Yoo et al. (2011) for the temporal evolution of heat release rate, pressure and density-weighted displacement speed. Ensemble averaged ODT results show good agreement with the DNS data. ODT results generated from varying the initial temperature fields show that the ignition delay time is highly sensitive to the initial temperature field. The ODT model uncertainty study shows that dispersion due to the stochastic nature of the model is considerably smaller than the dispersion resulting from varying the initial temperature field. Overall, this study demonstrates that ODT accurately captures the evolution of complex chemistry reactive flows in constant volume autoignition simulations and that once validated, ODT is an efficient tool that can be used to carry out parametric studies not feasible by DNS. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect