Christopher Geschwindner

Christopher Geschwindner
Technische Universität Darmstadt | TU · Department of Mechanical Engineering (Dept.16)

Master of Science

About

14
Publications
1,374
Reads
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63
Citations
Introduction
Experimentalist working on the development and application of high-speed laser-based diagnostics in reactive turbulent multi-phase flows. Currently part of the Collaborative Research Centre "Oxyflame" focusing on the combustion of biomass particles in laminar and turbulent boundary conditions.
Additional affiliations
July 2016 - September 2016
Technion - Israel Institute of Technology
Position
  • Graduate Research Intern
Description
  • Visiting student & researcher at the Turbo and Jet Engine Laboratory
July 2015 - September 2015
German Aerospace Center (DLR)
Position
  • Intern
Description
  • Intern working on laser-induced breakdown spectroscopy (LIBS)
Education
October 2015 - October 2018
Technische Universität Darmstadt
Field of study
  • Mechanical and Process Engineering

Publications

Publications (14)
Article
Full-text available
The application of a compact pulsed fiber laser for high-speed time-resolved particle image velocimetry (TR-PIV) measurements in the potential core of a turbulent round jet is presented at repetition rates of up to $$500\,\hbox {kHz}$$ 500 kHz . The master oscillator power amplifier laser architecture consists of a pulsable seed diode whose emissio...
Conference Paper
Full-text available
A novel single-cavity laser system with flexible pulsing schemes suitable for particle image velocimetry (PIV) measurements is presented. The system is based on the concept of picking selected pulse pairs from an ultra-high repetition rate fiber laser which enables time-resolved and conventional dual-pulse PIV at highly flexible recording frame rat...
Article
Full-text available
The present work reports an experimental study of particle group combustion of pulverized bituminous coal in laminar flow conditions using advanced multi-parameter optical diagnostics. Simultaneously conducted high-speed scanning OH-LIF, diffuse backlight-illumination (DBI), and Mie scattering measurements enable analyses of three-dimensional volat...
Article
The introduction of fibrous aspherical biomasses for the substitution of coal as a sustainable solid fuel causes complex particle-turbulence interactions, which need to be captured using minimally invasive laser-based diagnostics. High-resolution two-phase particle image velocimetry (PIV) of high-velocity biomass-laden turbulent flows require laser...
Article
The transition from single to group particle combustion is experimentally investigated in a laminar flow reactor. Optical techniques including two-colour pyrometry and a sampling probe provide data on surface temperature and composition of high-volatile bituminous coal particles during ignition, volatile combustion, and char burnout. Adjustable par...
Article
A well-characterized multi-hole gasoline injector, the Engine Combustion Network’s (ECN) Spray G injector, was investigated in an optically accessible research engine under four motored operating conditions with early injection. The experiments were conducted at intake pressures of 0.4bar and 0.95bar, nearly matching the ECN’s standard early inject...
Article
In this work, the Engine Combustion Network Spray G injector was mounted in the Darmstadt optical-accessible engine to study phenomena typical of multi-hole, early direct-injection events in spark-ignition engines characterized by tumble flow charge motion. Dedicated experimental measurements of both in-cylinder spray morphology and flow velocities...
Article
Full-text available
The homogeneous ignition and volatile combustion of pulverized solid fuel in single-particle and particle group configurations were studied numerically in a laminar flat flame burner. Simulations with increasing particle streams were performed to investigate the influence of the interactions in particle groups on homogeneous ignition and combustion...
Article
Full-text available
The ignition and volatile combustion of single coal particles were investigated under laminar conditions. Relevant physico-chemical processes were analyzed under conventional and oxy-fuel atmospheres with varying O2 contents in experiments and simulations. An optically accessible laminar flow reactor with well-defined boundary conditions measured w...
Article
Full-text available
Ignition and combustion of pulverized solid fuel is investigated in a laminar burner. The two-dimensional OH radical field is measured in the experiments, providing information on the first onset of ignition and a detailed characterization of the flame structure for the single particle. In addition, particle velocity and diameter are tracked in tim...
Article
Full-text available
The transition from single to group high-volatile bituminous (hvb) coal particle combustion is experimentally investigated in a laminar flow reactor using state-of-the-art laser diagnostics. Simultaneous volumetric OH-LIF imaging using a novel laser scanning technique is combined with time-resolved diffuse backlight-illumination (DBI) providing fun...
Article
The ignition and combustion of coal particle groups are investigated numerically in a laminar flow reactor. The Flamelet Generated Manifold method is extended to account for the complex mixture of gases being released during devolatilization, which is calculated with a competing two-step model. A second mixture fraction is introduced to include the...
Article
Full-text available
The combustion of micrometer-sized polypropylene (PP) particles is analyzed in situ using a combination of high-speed planar laser-induced fluorescence of the OH radical (OH-PLIF) and a thermal decomposition analysis. The gas phase is investigated by multiple analytical techniques to gain comprehensive knowledge on the decomposition products of fla...
Article
Full-text available
An investigation of the interaction between the in-cylinder flow and the spray topology in two spray-guided direct injection optical engines is reported. The bulk flow field in the combustion chamber is characterized using particle image velocimetry. Geometrical parameters such as the axial penetration and the spray angle of the liquid spray are me...

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Projects

Projects (2)
Project
At the centre of the project is an innovative cycle of energy and substance as important contribution to the energy transition. Energy can be stored in iron directly by electrochemical reduction or by using green hydrogen in a thermochemical reduction. The chemical energy is released again with high power densities via high-temperature thermochemical oxidation and reconverted into electricty in thermal power stations. Iron is a carbon-free energy carrier. Thus, the release will not emit carbon dioxide as greenhouse gas. Well packed, iron can be stored for long periods of time. This makes iron a chemical energy carrier to guarantee the supply by controllable power station capacities.
Project
Development of methods and models to describe solid fuel reactions within an oxy-fuel atmosphere