The
project B10 continues the research of project A6 in this CRC which was
terminated by the end of the second funding period. Subproject A6 was concerned
with the simulation of reactive and non-reactive flow in the near nozzle-region
of a model burner with the annular jet(s) issuing into the ambient. In the new
funding period the developed methodology will be extended to closed combustion
chambers. This calls for inserting the present project into the group B
“Complex, Composed Processes” of the CRC. In particular, the thermo-acoustic
instability will be investigated simulating the configuration of a burner in a
combustion chamber experimentally studied in the new subproject C6 of the CRC.
Another important change is the activity on reaction modeling newly proposed in
this project. While in A6 existing models were implemented, used and assessed,
part of the research in B10 will be devoted to the development of entirely new
reaction models in the framework of LES for premixed flames. Close interaction
with other projects concerned with modeling approaches and issues of LES will
take place, as well as exchange with C6, C10 focusing on experimental data to
be used for validation of the modeling efforts as well as other projects
treating the same burner under different conditions.
The
subproject is embedded in the project cluster "Combustion Chamber"
where the subprojects B9, B10, C1, C6, C7, C9 and C10 are integrated. The
ambition of this project cluster is to design and build a technical multiple
burner combustor (subproject C6) which is experimentally and numerically
investigated in subproject B9. The singe components of the multiple burner
combustor are well investigated in detail experimentally in subprojects C1 and
C10 and numerically in subprojects B9 and B10. The distinction between B9 and
B10 is that the former is focused on LES of the complete system, whereas the
latter is centered on developing combustion models for LES and implementing
this into the LES environment. Moreover, the codes in B9 and B10 are different
in so far as the one is density based (compressible) whereas the other one is
pressure based (variable density). The distinction between the experimental
subprojects lies in the focus on the entire system (B9) and low frequency
instabilities and the single systems and high frequency instabilities,
respectively (subproject C1 and C10). Furthermore, C1 has its focus on the flow
field whereas C10 investigates the "chemistry" of the system.
The main
goals of the subproject B10 are the development of new combustion models for
premixed turbulent flames, implementation and extension of other models being
developed within the CRC, and their application to the configuration of the new
experimental setup in subproject C6 realized during the funding period. This
will on a first level allow sound validation of the entire LES model. On a
second level, a closer understanding of the physics underlying the combustion
instabilities observed in this type of burner will be possible, which is of
relevance for industrial applications.
