Atomization processes
The research group is dedicated to the development and application of innovative laser-optical measurement methods and test rigs to improve the understanding of physical phenomena occurring in the context of liquid atomization and complex dispersed flows. Particular focus is placed on the analysis of multi-phase flows within nozzles, surface instabilities during jet breakup, mechanisms during droplet formation and evaporation, and mixture formation and interaction phenomena of the total spray. In addition, the group specializes in the development and application of nozzles for process optimization.
Nozzle Development
The development of nozzles for liquid atomization is being intensively pursued as part of various projects. Examples:
- Variation of nozzle geometry for targeted production of nano-materials in the context of spray flame synthesis (project: DFG SPP1980 )
- Development of bronchoscopic nozzles for lung-internal application of stem cells for the therapy of acute lung injury (project: DFG RE 4092/2-1 )
- Use of transparent nozzles for contactless flow measurements (project : FSC CA2-02-02 , see figure)
The nozzle types used in this process are diverse. Both high-pressure atomizers and low-pressure atomizers (two-substance nozzles, coaxial, effervescent, ultrasonic) are used.
Stationary test benches / laboratories
In 7 individual laboratories covering an area of 300 m², the group develops and operates various test benches. These enable reproducible setting of the boundary conditions relevant for the respective field of application and at the same time provide the necessary optical access for specific measurement methods (further information on request).
Laser-optical methods
For comprehensive determination of characteristic length and time scales of multiphase flows as well as temperatures and pressures, complementary measurement methods are available (further information on request):
- Ultra-high-speed visualization up to 5 million fps incl. automated image analysis (e.g. for droplet size and velocity)
- Multicolor laser-induced fluorescence , e.g. for determination of temperature fields in microdroplets and liquid sprays as well as for measurement of film thickness distributions
- Phase Doppler anemometry (DPSS laser based) for spatially and temporally resolved measurement of droplet size and velocity distributions
- Interferometers (including high-speed Fizeau interferometers) for characterization of liquid films
- Particle Image Velocimetry, Laser Correlation Velocimetry and Laser-Doppler Velocimetry for flow field measurement
- Pressure and temperature sensing
Current Projects
In the field of atomization, various industrially and publicly funded projects are addressed. A selection :
- DFG RE 4092/2-1: Development of an intrapulmonary spray method for cell therapy
- DFG SPP1980: Impact of atomization on particle synthesis in spray flames
- DFG KN 764/17-1: Experimental and numerical analysis of the interaction of sprays with thin wallfilms
- DFG ZUK II, RWTH Start-Up 333-18: Influence of pressure and velocity gradients during atomization on deformation and viability of mesenchymal stem cells
- DFG EXC 2186-FSC: Fundamental investigation of spray and droplet interaction phenomena in advanced combustion systems
- DFG EXC 2186-FSC: Fuel-adapted manipulation of nozzle-internal and external breakup mechanisms for molecularly-controlled mixture formation
- DFG EXC 2186-FSC: Local analysis and evaluation of innovative fuel-adaptive exhaust-gas abatement and aftertreatment strategies
- BMWi ZIM PPA-Profil PDA: Development of a line phase Doppler Anemometer for simultaneous measurement of position, size and velocity of droplets or particles