Data-assisted combustion simulations with dynamic submodel assignment
using random forests
- URL: http://arxiv.org/abs/2009.04023v3
- Date: Sun, 17 Jan 2021 20:24:28 GMT
- Title: Data-assisted combustion simulations with dynamic submodel assignment
using random forests
- Authors: Wai Tong Chung, Aashwin Ananda Mishra, Nikolaos Perakis, Matthias Ihme
- Abstract summary: We outline a data-assisted approach that employs random forest classifiers for local and dynamic combustion submodel assignment.
This method is applied in simulations of a single-element GOX/GCH4 rocket combustor.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: In this investigation, we outline a data-assisted approach that employs
random forest classifiers for local and dynamic combustion submodel assignment
in turbulent-combustion simulations. This method is applied in simulations of a
single-element GOX/GCH4 rocket combustor; a priori as well as a posteriori
assessments are conducted to (i) evaluate the accuracy and adjustability of the
classifier for targeting different quantities-of-interest (QoIs), and (ii)
assess improvements, resulting from the data-assisted combustion model
assignment, in predicting target QoIs during simulation runtime. Results from
the a priori study show that random forests, trained with local flow properties
as input variables and combustion model errors as training labels, assign three
different combustion models - finite-rate chemistry (FRC), flamelet progress
variable (FPV) model, and inert mixing (IM) - with reasonable classification
performance even when targeting multiple QoIs. Applications in a posteriori
studies demonstrate improved predictions from data-assisted simulations, in
temperature and CO mass fraction, when compared with monolithic FPV
calculations. These results demonstrate that this data-driven framework holds
promise for the dynamic combustion submodel assignment in reacting flow
simulations.
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