Passive scalar interface in a spatially evolving mixing layer (A. Attili and D. Denker)

Quartz nozzle sampling (D. Felsmann)

Dissipation element analysis of a planar diffusion flame (D. Denker)

Turbulent/non-turbulent interface in a temporally evolving jet (D. Denker)

Dissipation elements crossing a flame front (D. Denker and B. Hentschel)

Particle laden flow (E. Varea)

Turbulent flame surface in non-premixed methane jet flame (D. Denker)

DNS of primary break up (M. Bode)

Diffusion flame in a slot Bunsen burner (S. Kruse)

Various quantities in spatially evolving jet diffusion flame (D. Denker)

ERC Advanced Research Grant "Milestone": Multi-Scale Description of Non-Universal Behavior in Turbulent Combustion


Overview

Visualization of a DNS of a temporally evolving sooting n-heptane jet flame featuring soot formation at high jet Reynolds number. The complex interplay of reactants, temperature and soot fields within the turbulent flame is shown by different iso-surfaces.

The development of new, step-change technologies in the field of combustion is essential to enable sustainable next-generation combustion devices and greatly benefits from design based on numerical simulations. However, turbulent combustion physics is complex, highly non-linear, of multi-scale and multi-physics nature, and involves interactions on many time scales. This makes modeling quite challenging and accurate predictive models, especially for the formation of pollutants, are still not available. Today, there are two major challenges for achieving predictive simulations of turbulent combustion. First, its multi-scale nature must be accounted for by considering the non-universal behavior of small-scale turbulence, which is known to be critically important for turbulence-chemistry interactions. Second, sufficiently detailed data is required for rigorous analysis of model deficiencies and unambiguous model development. The MILESTONE work addresses these two issues, and the main objectives are described in the following.


Objectives

1) Establish a new multi-scale framework to analyze and model turbulent combustion phenomena based on a new way to describe turbulence using so-called dissipation elements, which are space-filling regions in a scalar field allowing to capture its small-scale morphology and non-universality. Further details can be found here.

2) Create new unprecedented datasets using direct numerical simulations (DNS) and provide new analysis methods to develop and validate combustion models: Automatically reduced and optimized chemical kinetic mechanisms combined with on-the-fly chemistry reduction techniques DNS accounting for pollutant formation. Further details can be found here.

3) Apply new modeling approaches to complex and highly non-linear modeling questions, such as pollutant formation in turbulent spray combustion. The project will provide new and unprecedented datasets, a quantitative description of the impact of non-universality in small-scale turbulence on different aspects of turbulent combustion, and the basis for an entirely new multi-scale closure. Further details can be found here.