Numerical simulations of turbulent reacting flows with finite-rate chemistry and combustion-model adaptation

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Abstract/Contents

Abstract
The utilization of finite-rate chemistry with realistic chemical kinetics in large-eddy simulations (LES) of turbulent reacting flows has attracted increasing interest in recent years. It enables further improvement in the prediction of emissions in the combustion process and helps eliminate the restriction often imposed by regime-specific combustion models. However, the cost of such approaches remains a great concern despite the continuing growth of computational capacity, as they are often orders-of-magnitude more expensive than the regime-specific flamelet-type models. In this study, the framework of Pareto-efficient combustion (PEC) modeling is developed, which allows the adaptive utilization of multiple combustion models under consideration of cost-fidelity characteristics for efficient simulations of complex turbulent flames. This adaptive approach provides a general combustion modeling capability with an adjustable level of fidelity and complexity. Based on the user-specific inputs on quantities of interest, desired simulation accuracy and computational cost, the PEC framework makes adaptive model assignments restricting the application of sub-models within their intended use. For complex problems, the proposed framework allows the usage of detailed description of the combustion chemistry in limited regions where it is necessary, while avoiding the concomitant overhead in regions where flamelet-type models are deemed sufficient. Efficient computational strategies are developed to accelerate large-scale parallel simulations with stiff finite-rate chemistry, including time stepping methods and load rebalancing techniques. The combined approach is applied to LES of turbulent flames, demonstrating its capability in improving the predictability and cost-effectiveness of turbulent combustion simulations.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2018
Issuance monographic
Language English

Creators/Contributors

Associated with Wu, Hao
Associated with Stanford University, Department of Mechanical Engineering.
Primary advisor Ihme, Matthias
Thesis advisor Ihme, Matthias
Thesis advisor Moin, Parviz
Thesis advisor Wang, Hai, 1962-
Advisor Moin, Parviz
Advisor Wang, Hai, 1962-

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Hao Wu.
Note Submitted to the Department of Mechanical Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2018.
Location electronic resource

Access conditions

Copyright
© 2018 by Hao Wu
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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