URL study guide
https://tue.osiris-student.nl/onderwijscatalogus/extern/cursus?cursuscode=4BM30&collegejaar=2025&taal=enDescription
More than 80% of our energy is being generated by conversion of fossil and sustainable fuels in appliances like engines, gas turbines, gasifiers, fuel cells, ovens and furnaces in the (process)-industry and burners in domestic and industrial boilers and combustors. The large scale applications are always turbulent. The physical transport processes as well as the chemistry, with which these processes in the diverse set of mentioned applications can be described, will be treated. The course will start with a global description of turbulent flows and the elementary combustion concepts of premixed and non-premixed combustion. Then fundamental interactions between turbulence and combustion will be discussed. There will be subsequent attention for combustion stability and emissions. For practical applications we will consider mainly gas turbines, both for electricity generation (stationary, land based) as well as for aero-turbines (aircraft propulsion), but also engines and furnaces. The description of the different processes in a CFD context will get a lot of attention.The course is strongly oriented towards understanding of modern models and implementation of those in CFD (computational fluid dynamics) codes. This will take place in an actual case in which use is made of the software package ANSYS which is a tool for multi-physics modeling including CFD. This will be combined with the application Cantera, which is an open-source code for detailed chemical reaction modeling. This hands-on approach will cover a large part of the course. Finally every student has to write a scientific report based on the results of his/her modelling efforts.
The course will start with describing the Navier Stokes equations and the use of ANSYS Fluent for steady laminar flows. Then we will increase the complexity step by step to end at turbulent combustion. First a non-reacting flow around an obstacle will be considered in order to get acquainted with the software and to study convergence and the influence of mesh resolution. In the next step, chemical reactions are added to the model and premixed laminar flames stabilized in the wake of a bluff body are studied. The influence of reaction mechanism is investigated. In the next step, a chemical reduction method (FGM) is studied and applied to the same bluff-body flame. Finally turbulence is included in the modelling. Various turbulent combustion models are explained and used to model bluff-body stabilized turbulent flames as found in after burners of jet engines. The last phase is dedicated to non-premixed combustion. Non-premixed laminar flamelets are investigated using Cantera and turbulent jet flames are simulated in Fluent with various flamelet models.