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Application to technical combustion system

Mobile CARS system on a crane hook, for a measuring campaign on a combustion rig with 300 kW thermal load.

The Department has several mobile laser-based measurement systems. They are designed for use on combustion systems outside the laboratory and are deployed for measurement campaigns carried out for customers. Two mobile CARS systems are configured for temperature measurements using the single-pulse technique, in which the air nitrogen present during combustion is used as an indicator. In the case of sooting flames, the modified SV-CARS variant is used. Other mobile systems are available for investigating the structures, stabilisation and blow-out limit of flames, as well as two-dimensional distributions of temperature, species and soot using LIF, Raman and LII techniques. LIF systems with pulse rates greater than 1 kHz are likewise designed as mobile facilities. The following list provides some examples of work carried out in national and international projects and for customers.

• Temperature measurements with CARS in experimental furnaces with 300 kW thermal power, fired by natural gas and coal dust
• CARS measurements to calibrate high-temperature suction pyrometer probes in a natural gas/oxygen burner doped with N2 and having a thermal power rating of 1 MW
• " Experiments with a combustion chamber for hypersonic propulsion systems, operated at atmospheric pressure with a hydrogen/air mixture, with CARS being used for temperature measurement and LIF for the characterisation of flame stability and structure
• " Temperature measurements (CARS) and flame structure experiments (LIF) on a hydrogen/air-breathing Ramjet combustion chamber segment, at a combustion chamber pressure of 3 bar
• Laser-based measurements in combustion chamber segments for aero engines, at pressures up to 16 bar, in order to characterise the fuel distribution (LIF), flame position (LIF) and hence the wall load of the combustion chamber and the temperature distribution (CARS)
• Measurement of OH chemiluminescence and OH fluorescence in novel, technically useable burner configurations in order to assess the stability behaviour of the flame, at pressures up to 20 bar
• Axial and radial temperature distribution (CARS) in a can-type combustion chamber fired with natural gas and oil
• Flame structure and stability tests using LIF in a step-stabilised subsonic measuring section fired with methane
• Characterising the mixture and temperature distribution in the combustion chamber of close-to-production internal combustion engines with 2D-LIF
• 1D Raman measurements (along a line) to determine the distributions of the major species during combustion oscillations
• 1D Raman measurements in an industrial gas turbine burner to characterise the mixture and turbulence-chemistry interaction
• 2D Raman measurements (special application for a maximum of two species) in a cryo-injector test bench, in order to characterise jet decay and mixture under supercritical conditions
• Measurement of soot distribution (LII) in a combustion channel at an operating pressure of 3 bar and a reactor for producing nanotubes
• Soot measurements with LII in a model aircraft engine combustion chamber, at pressures up to 23 bar
• Measurement of flow fields in model gas turbine combustion chambers using the PIV technique
• Experimental studies on re-ignition of aircraft engines using the LIF technique in an “altitude relight” test rig