A5023025351- Combustion and flame dynamics
- Advanced Combustion Engine Technologies
- Spectroscopy and Laser Applications
- Vehicle emissions and performance
- Fluid Dynamics and Turbulent Flows
- Catalytic Processes in Materials Science
- Heat transfer and supercritical fluids
- Radiative Heat Transfer Studies
- Laser Design and Applications
- Particle Dynamics in Fluid Flows
- Ultrasound and Cavitation Phenomena
- Nuclear Physics and Applications
- Rocket and propulsion systems research
- Laser-induced spectroscopy and plasma
- Electrohydrodynamics and Fluid Dynamics
- Combustion and Detonation Processes
- Atmospheric and Environmental Gas Dynamics
- Tribology and Lubrication Engineering
- Wind and Air Flow Studies
- Spectroscopy and Chemometric Analyses
- Mass Spectrometry Techniques and Applications
- Fluid Dynamics and Heat Transfer
- Fire dynamics and safety research
- Aerodynamics and Fluid Dynamics Research
- Chemical Thermodynamics and Molecular Structure
Fraunhofer Institute for Solar Energy Systems
2020-2025
Federal Institute For Materials Research and Testing
2024
University of Duisburg-Essen
2015-2024
Leibniz University Hannover
2018-2023
LMU Klinikum
2022
Ludwig-Maximilians-Universität München
2022
Max Planck Institute for Terrestrial Microbiology
2022
Sandia National Laboratories California
2005-2011
Sandia National Laboratories
2008-2009
Yale University
2002-2005
We report the first application of a vertical-cavity surfaceemitting laser (VCSEL) for calibration- and sampling-free, high-speed, in situ H2O concentration measurements IC engines using direct TDLAS (tunable diode absorption spectroscopy). Measurements were performed single-cylinder research engine operated under motored conditions with time resolution down to 100 μs (i.e., 1.2 crank angle degrees at 2000 rpm). Signal-to-noise ratios (1σ) up 29 achieved, corresponding precision 0.046 vol.%...
Abstract Combusting metal precursor-laden droplets, required in spray-flame synthesis of nanomaterials, are known to undergo a rapid and disruptive disintegration, i.e., puffing micro-explosion. In this work, imaging with high spatiotemporal resolution image-analysis routines were developed investigate droplet disruption oxides. Droplet shadowgraphs imaged on high-speed camera. The solvent was mixture 35 vol% ethanol 65 2-ethylhexanoic acid which (in some cases) mixed 0.2 mol/l iron(III)...
Thermally-induced breakup of metal-precursor-laden droplets in spray-flame synthesis occurs via a rapid and disruptive disintegration, i.e., "puffing" "micro-explosion". To assess the temporal evolution statistics droplet disruption, LED-illuminated shadowgraphs were imaged with microscope onto high-speed camera morphological image analysis was applied. The atomized liquid mixture 35 vol.-% ethanol 65 2-ethylhexanoic acid mixed iron(III) nitrate nonahydrate (INN) as precursor. Droplet...
Polygeneration is the coupling of energy conversion and towards useful chemicals, providing a route more flexible efficient systems. In this work, we explore particular concept polygeneration using an internal combustion engine as reactor for partial oxidation to generate synthesis gas in variable combinations with mechanical work heat. Experiments were performed single-cylinder operated homogeneous-charge compression-ignition (HCCI) mode on mixture methane air dimethyl ether (DME)...
The time evolution of the liquid-film thickness a single cavitation bubble in water collapsing onto solid surface is measured. To this end, total internal reflection (TIR) shadowmetry developed, technique based on TIR and imaging shadows an optical structure polished glass surface. measurements are performed at frame rates up to 480 kHz. Simultaneous high-speed shape 89 kHz allows relating film dynamics. With typical maximum radius 410 µm, we varied nondimensional stand-off distance γ from...
Abstract Spray-flame synthesis uses low-cost precursors dissolved in organic solvents to produce functional metaloxide nanoparticles. In the spray flame, precursor-laden droplets show frequent and intense thermally-induced disruption, so-called puffing micro-explosion. This process is often correlated with high uniformity of particle sizes. Whether micro-explosion are also directly associated formation or release iron oxide nanoparticles not clear. Also, spatiotemporal evolution turbulent...
This paper reports the validation of a three-dimensional numerical simulation mixture preparation in direct-injection (DI) hydrogen-fueled engine. Computational results from commercial code CONVERGE are compared to experimental data obtained an optically accessible The geometry used is passenger-car sized, four-stroke, and spark-ignited includes combustion chamber as well intake exhaust ports. hydrogen supplied at 100 bar centrally located injector with single-hole nozzle. comparison between...