Combustion processes are reacting flows, characterised by a complex interaction between flow, chemical reaction and molecular transport. They can be solved numerically by solving the underlying conservation equations for mass, momentum, energy and species masses. The modelling of technical combustion systems is hampered by the fact that the typical time, length and speed scales differ by several orders of magnitude. Therefore, direct numerical simulation of technical systems that resolves the smallest scales, is impractical even with the fastest available mainframe computers.
ITT develops advanced methods for predicting reacting flows in technical processes (e.g. for energy transformation or in process engineering). This takes place through a systematic combination of experiments, model development and numerical simulation.
Hierarchical modelling approaches are used, in which the results of experiments and of the simulations of detailed systems (e.g. of vortices, which interact with flame fronts) are used to develop models for technical systems. The projects conducted at ITT, therefore encompass the entire range of numerical simulations, from detailed simulations to the modelling of technical combustion systems.
Aspects such as resource conservation, further tightening of the legislation relating to pollutant minimisation during combustion processes, and economic criteria constitute the motivation for ITT’s research activities, in order to improve the mostly oversimplified modelling assumptions for many kinetically controlled processes, such as e.g. pollutant formation or turbulence-chemistry interactions. Here, detailed experiments are used to develop sub-models which then permit more realistic predictions (e.g. through numerical simulations) in technical applications.