Host Institution: Université Libre de Bruxelles (Belgium)
Department of Aero-Thermo-Mechanics, Université Libre de Bruxelles
Phone: +32 498526001
Research interests
In recent years, there has been an increasing interest for the use of Principal Component Analysis for the development of reduced-order combustion models. The PCA modelling framework has been demonstrated a priori and a posteriori for a wide range of configurations, including simple batch and perfectly stirred reactors, one-dimensional laminar flames and complex cases such as flame-vortex interaction as well as plasma flows. Results indicated that PCA-based models are able to provide very accurate results when compared to full size simulations. Current investigations have shown that PCA models are relatively invariant to parameters such as the Reynolds number of the flow. This implies that PCA models can be trained on relatively simple systems and used to simulated systems showing more complex turbulence/chemistry interactions. However, it appears still necessary to determine and quantify the validity range of PCA models, to determine: the required degree of complexity of the chemical reactor used to generate the model; and the conditions at which the reduced models will not be valid anymore.
Education
Project title: Development of PCA–based reduced models for natural gas combustion
Objectives. In recent years, there has been an increasing interest for the use of Principal Component Analysis for the development of reduced-order combustion models. The PCA modelling framework has been demonstrated a priori and a posteriori for a wide range of configurations, including simple batch and perfectly stirred reactors, one-dimensional laminar flames and complex cases such as flame-vortex interaction as well as plasma flows. Results indicated that PCA-based models are able to provide very accurate results when compared to full size simulations. Current investigations have shown that PCA models are relatively invariant to parameters such as the Reynolds number of the flow. This implies that PCA models can be trained on relatively simple systems and used to simulated systems showing more complex turbulence/chemistry interactions. However, it appears still necessary to determine and quantify the validity range of PCA models, to determine: i) the required degree of complexity of the chemical reactor used to generate the model; and ii) the conditions at which the reduced models will not be valid anymore.
Expected results. The objective of the present ESR are twofold: to extend the PCA modeling approach to relatively large kinetic mechanisms as the ones applicable to conventional and unconventional natural gas based fuels, and to validate the PCA approach in the framework of Large Eddy Simulation. For the former objective, PCA will be first in the framework of high-fidelity simulation tools such as DNS and ODT (One Dimensional Turbulence). This will the necessary to identify the required strategies to deal with relatively large kinetic mechanism (non-linear regression, kernel PCA, ...). The validation of PCA in the framework on LES will require the development of appropriate sub-grid strategies. At this stage, potential candidates include the Rate-Controlled Constrained Equilibrium (RCCE) and the Eddy Dissipation Concept (EDC) (from ESR 14).
Planned secondment. FR-ECP (8-10 months). Extension of PCA to LES.