# Multiscale Modeling of Supercritical Combustion with Two-Level Simulation on Adaptive Beamlets

## Abstract

Supercritical carbon dioxide (sCO _{2}) direct-powered turbine technology is a promising choice for the next generation of high-efficiency and low-emissions fossil fuel power systems. Breakthrough improvements in the design and development of the sCO _{2} oxy-combustion devices are hampered by the lack of high-fidelity simulation tools suitable for the supercritical highly-CO _{2} diluted reactive flow environment. The critically missing capabilities in many commercial and research codes exist due to the unaccounted effects of many nonlinearities, and the small-scale complex processes which become prominent at supercritical conditions. The present approach aims to address many shortcomings of the currently used models by adopting and generalizing a multiscale modeling concept of the Two-Level Simulation (TLS). In the TLS, all small-scale flow fields are simulated explicitly, albeit on one-dimensional (1D) domains -- beamlets represented by a collection of line segments embedded in a three-dimensional (3D) computational domain. In this research, we laid theoretical groundwork needed for application of the developed approach to variable density turbulent reacting flows and to sCO _{2} combustors, in particular. The small-scale governing equations on the beamlets were introduced and analyzed by drawing a comparison with the supercritical Direct Numerical Simulation (DNS) data sets to validate the TLS modeling assumptions.more »

- Authors:

- Sympectic Research Inc., Atlanta, GA (United States)

- Publication Date:

- Research Org.:
- Sympectic Research Inc., Atlanta, GA (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC)

- OSTI Identifier:
- 1416024

- Report Number(s):
- DOE-SYMPL-SC0017241-1

- DOE Contract Number:
- SC0017241

- Type / Phase:
- SBIR (Phase I)

- Resource Type:
- Technical Report

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 30 DIRECT ENERGY CONVERSION; 42 ENGINEERING

### Citation Formats

```
Kemenov, Konstantin A., and Akkerman, Vyacheslav.
```*Multiscale Modeling of Supercritical Combustion with Two-Level Simulation on Adaptive Beamlets*. United States: N. p., 2018.
Web.

```
Kemenov, Konstantin A., & Akkerman, Vyacheslav.
```*Multiscale Modeling of Supercritical Combustion with Two-Level Simulation on Adaptive Beamlets*. United States.

```
Kemenov, Konstantin A., and Akkerman, Vyacheslav. Fri .
"Multiscale Modeling of Supercritical Combustion with Two-Level Simulation on Adaptive Beamlets". United States.
```

```
@article{osti_1416024,
```

title = {Multiscale Modeling of Supercritical Combustion with Two-Level Simulation on Adaptive Beamlets},

author = {Kemenov, Konstantin A. and Akkerman, Vyacheslav},

abstractNote = {Supercritical carbon dioxide (sCO2) direct-powered turbine technology is a promising choice for the next generation of high-efficiency and low-emissions fossil fuel power systems. Breakthrough improvements in the design and development of the sCO2 oxy-combustion devices are hampered by the lack of high-fidelity simulation tools suitable for the supercritical highly-CO2 diluted reactive flow environment. The critically missing capabilities in many commercial and research codes exist due to the unaccounted effects of many nonlinearities, and the small-scale complex processes which become prominent at supercritical conditions. The present approach aims to address many shortcomings of the currently used models by adopting and generalizing a multiscale modeling concept of the Two-Level Simulation (TLS). In the TLS, all small-scale flow fields are simulated explicitly, albeit on one-dimensional (1D) domains -- beamlets represented by a collection of line segments embedded in a three-dimensional (3D) computational domain. In this research, we laid theoretical groundwork needed for application of the developed approach to variable density turbulent reacting flows and to sCO2 combustors, in particular. The small-scale governing equations on the beamlets were introduced and analyzed by drawing a comparison with the supercritical Direct Numerical Simulation (DNS) data sets to validate the TLS modeling assumptions. A series of the 2D DNS studies of premixed flame propagation in pipes, in a highly CO2-diluted environment, was performed in order to elucidate the effects of dilution on the laminar burning velocity, flame thickness, as well as on the dynamics and morphology of a corrugated flame front. The demonstrated approach could be applicable to high-fidelity modeling of other supercritical combustion devices including liquid rocket engines.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2018},

month = {1}

}