Combustion in aero engines - VKI LS
Date: Monday 01 February 2010 to Friday 05 February 2010
Location : von Karman Institute for Fluid Dynamics, Rhode-St-Genèse, Belgium
COMBUSTION IN AERO ENGINES
From February 1 to February 5, 2010
von Karman Institute, Rhode-St-Genèse, Belgium
High pressure two-phase air-kerosene reacting flow, with high levels of turbulence and heat transfer submitted to acoustic waves: this is how the flow in an aero engine combustor could be characterized. In addition, the environmental concerns, which are calling for lower NOx emissions, have become strong technological drivers that need to be taken into account during the design phase. Therefore the lectures will put a particular emphasis on the basic phenomena involved in Low Nox combustor and attempt to establish strong links between fundamental knowledge and design requirements.
The first lecture will provide an overall view on the combustor design, the associated main requirements that have to be answered and the trade-offs that have to be solved. Examples of preliminary design tools will be presented and the relevant regulations addressed.
The next lectures will put emphasis on the physics rather than on the modelling issues starting with fuel injection, spray formation, atomisation, droplets-turbulence interaction and evaporation phenomena which highly contribute to the determination of the combustion process output. Multicomponents evaporation will be particularly discussed in view of its importance for altitude relight as well as active methods that can be used to enhance atomisation.
This will be followed by the chemistry of combustion with a particular focus on pollutants formation from kerosene oxidation. To address the topic of turbulence / combustion interactions, the starting point will consist in the investigation of the basic mechanisms by which turbulence can influence or modify the different flame structures that are encountered in Low NOx combustor technologies.
Then, the basic aerodynamic processes will be outlined including the specific requirements of Low NOx systems. Emphasis will be placed on the aerodynamics of swirl stabilised combustion including mixing and unsteadiness from large scale structures and their sensitivity to acoustic waves. Examples will be provided from experimental and numerical studies.
The presentation on combustor heat transfer and cooling aspects will identify the main governing parameters for this complex problem. The issues regarding the current cooling techniques (film,
A wide operability domain of the combustor is very important for safety requirements. Therefore, two sessions will be dedicated to ignition, altitude relight as well as combustion instabilities to which lean combustion is particularly sensitive.
A specific session will be dedicated to LES viewed as an analysis and design tool for Low NOx combustors. The current status of LES achievements regarding the corresponding design needs will be made and discussed in order to assess the confidence level of such tool.
The following session will be devoted to a state-of-the-art on technology achievements and on current experimental demonstration of lean combustors being carried out. A glimpse on innovative technologies will be made from some examples in order to highlight the extreme importance of knowledge integration into design.
As a perspective, the course will be concluded with a lecture on the opportunities of alternative fuels for aeronautics. What are the requirements from the engine? What are the benefits regarding climate change? Where are we with the research on alternative fuels for aero engines?
The Lecture Series Directors are R. Dénos, European Commission and M. Cazalens, Snecma. The local organizer is Prof. J. van Beeck
Monday February 1, 2010
09:00 Welcome Address
09:30 Introduction to aero engine gas turbine combustion
11:00 Introduction to aero engine gas turbine combustion (Cont’d)
14:00 Fuel injection and spray evaporation
15:45 Fuel injection and spray evaporation (Cont’d)
Tuesday February 2, 2010
9:00 Heat transfer and cooling
11:00 Heat transfer and cooling (Cont’d)
14:00 Aerodynamics, mixing and unsteadiness
15:45 Aerodynamics, mixing and unsteadiness (Cont’d)
Wednesday February 3, 2010
9:00 Chemistry / Physics of turbulent combustion
11:00 Chemistry / Physics of turbulent combustion (Cont’d)
14:00 Visit of the VKI Labs
Thursday February 4, 2010
9:00 Operability: ignition, altitude relight
10:45 Operability: combustion instabilities
14:00 Analysis of combustor flow using large eddy simulation
15:45 Analysis of combustor flow using large eddy simulation (Cont’d)
Friday February 5, 2010
9:00 Experimental demonstration of lean technologies
10:45 Alternative Fuels
14:00 End of Lecture Series
|From 1.02.2009 to 5.02.2009|