Numerical Simulation of Turbulent Combustion on CRESCO Platform
E. Giacomazzi, F.R. Picchia, D. Cecere, N. Arcidiacono
ABSTRACT
Computational Fluid Dynamics (CFD) is increasing its importance in the design of systems involving reacting
turbulent flows like industrial combustion devices. The associated complex physics demands for accurate
models and advanced numerical methods. Nowadays supercomputing makes feasible using powerful CFD
approaches like LES (Large Eddy Simulations), which is able to meet such demands. CRESCO platform,
recently installed in Portici, has absolutely increased computing capabilities of the ENEA research team in
combustion. The aim of this work is to show some results of turbulent combustion related problems obtained
by means of the ENEA HeaRT code run on CRESCO. HeaRT (Heat Release and Turbulence) is a fully
compressible, reactive, unsteady flow solver that implements an original LES subgrid scale model, named
Fractal Model. In particular, the main issues of two test cases are discussed. The first one is the
Sandia/ETH-Zurich CO/H2/N2 non-premixed unconfined turbulent jet flame. This flame is simulated in a
three-dimensional axisymmetric formulation. The most important scientific issue related to this flame is its
anchoring, analyzed in detail to evidence the controlling physical mechanisms. Besides this, comparison with
experimental data is also provided. The second test case is a combustor of Politecnico of Milan that can
operate in MILD combustion flameless regime. MILD combustion is one of the promising techniques to
reduce pollutant emissions, such as NOx. In particular, the conditions and results presented here refer to a
Hydrogen/Air mixture. Most of the global flame properties are well captured by the 3D simulation performed.
Radiant transfer of energy is taken into account. The predictions of temperature and NOx are compared with
available experimental results. These results are among the first unsteady results of MILD combustion and
give a spot to the influence of turbulence on MILD regime.Finally, computing time and speed-up will be also
presented.