Zhiyao Yin, Ph.D.

Laser spectroscopist, plasma/combustion scientist, data enthusiast and hobby programmer

Stuttgart, Germany


Projects

CARSpy

CARSpy
A python module for synthesizing and fitting experimental coherent anti-Stokes Raman (CARS) spectra.
  • Comprehensive physical models: G-matrix, Expoential Gap Model, Voigt line profiles, T-K convolution
  • Optional chemical equilibrium (with Cantera)
  • Optional vibrational and rotational nonequilibrium
  • Extendable for various species and CARS configurations
  • Interactive webapp based on Dash-Plotly
CARS Spectroscopy Numpy Scipy Cantera Sphinx Dash-Plotly Bootstrap

MRPOD

MRPOD
A python module for Multiresolution Proper Orthogonal Decomposition (MRPOD) of multidimensional image time series.
  • 2D discrete wavelet decomposition and reconstruction
  • Principle Component Analysis (PCA) in well-defined frequency domain
Discrete Wavelet Transform PCA Numpy Scipy Sphinx

PyLAT

PyLAT
A python module for tomographic reconstruction of 1-D two-color laser absorption with irregularly arranged diode lasers.
  • Classical reconstruction methods (e.g. ART, SIRT, Landweber)
  • Tikhonov regularization
  • Neural network (e.g., CNN) based reconstruction (planned)
Tomography Spectroscopy Machine Learning Numpy Scipy

Pythonize

Pythonize
A knowledge base for data crunching and visualization in Python.
  • Tutorial-style blog posts based on executable Jupyter Notebooks
  • Central topics include laser spectroscopy, fluid dynamics, machine learning and finance
Spectroscopy Machine Learning Jupyter Book Matplotlib Plotly Pandas Numpy Scipy Scikit-Learn TensorFlow Sphinx

Work

2014 - Present

Research Scientist

German Aerospace Center (DLR)
Stuttgart, Germany
Combustion diagnostics, data analytics:
  • Highspeed laser diagnostics for the quantification of temperature, velocity and species concentrations in next-gen combustion systems
  • Quantitative spray imaging for particle sizing and velocimetry
  • Machine-learning based data analysis, especially for multidimensional image time series (PCA, CNN, Autoencoders)
  • Project subtask lead: "Soot Processes and Radiation in Aeronautical Innovative Combustion (SOPRANO)" (EU2020, Grant Agreement No.690724)
  • Spectroscopy algorithm development with Python
  • Principle Investigator: "Understanding the turbulent flame dynamics of jet-stabilized gas turbine combustors" (Helmholtz Postdoc Fellowship, Grant PD-112)

2013 - 2014

PostDoc

Ohio State University
Columbus, OH, USA
Quantitative laser spectroscopies for a liquid/gas plasma reactor

2008 - 2013

Research Associate

Ohio State University
Columbus, OH, USA
Plasma physics, plasma-assisted combustion:
  • Quantitative laser spectroscopies in nonequilibrium low-temperature plasmas
  • Kinetic modeling and applications of plasma-assisted combustion
  • Project subtask lead: "Fundamental aspects of plasma-assisted combustion" (AFOSR)

Education

2013

Ph.D. in Mechanical Engineering

Ohio State University
Columbus, OH, USA
Dissertation:

Fuel oxidation and ignition by nanosecond pulse discharge at elevated temperatures

2008

B.S. in Naval Architecture

Huazhong University of Science and Technology
Wuhan, Hubei, China
Thesis:

2D Simulation of supercavitation on a NACA0012 airfoil


Awards/Certificates

2020

TensorFlow Developer Certificate

TensorFlow Certificate Program

ID: 25378502

2020

DeepLearning.AI TensorFlow Developer Specialization

Coursera

Computer vision, Sequences, Time Series, Natural Language Processing

2019

telc Deutsch C1

telc GmbH - The European Language Certificates

Prädikat: Gut

2017

Best Paper

2017 ASME Turbo Expo

DOI: 10.1115/GT2017-65003

2014

Helmholtz Postdoc

Helmholtz-Gemeinschaft Deutscher Forschungszentren

3-year program with 150 k€ funding

2014

Distinguished Paper

35th International Symposium on Combustion

DOI: 10.1016/j.proci.2014.05.073

2012

Distinguished Paper

34th International Symposium on Combustion

DOI: 10.1016/j.proci.2012.07.015

2008

Distinguished University Fellowship

Ohio State University

2-year full graduate school fellowship in the Department of Mechanical and Aerospace Engineering


Skills

Experimental Systems

(kHz-Rate) High Energy Solid-State and Dye Lasers, (kHz-Rate, intensified) CCD/CMOS Camera Systems, and Nanosecond Pulse Discharges

Optical Diagnostics

Mie Scattering, Particle Image Velocimetry (PIV), Laser Absorption Tomography, Coherent Anti-Stokes Raman Spectroscopy (CARS), (Planar) Laser-Induced Fluorescence (LIF), (Microscopic) Laser Shadowgraphy, Phosphors Thermometry, and Emission Spectroscopy

Programming

Python, Matlab, HTML/(S)CSS, and C++

Softwares

LaTeX, LabView, Catia, Origin, and DaVis

Machine Learning

TensorFlow, Scikit-Learn, and Pandas

Web Dev

Plotly/Dash, Django, Jekyll, Sphinx, and Bootstrap


Languages

Chinese

Native speaker (Mandarin)

English

Fluent (C2+)

German

Fluent (C1+)

French

(~A2-B1)

Japanese

(~A1-A2)


Selected Publications

2021

Experimental investigations of superheated and supercritical injections of liquid fuels

Z. Yin, P. Kutne, J. Eichhorn, W. Meier

Journal of Engineering for Gas Turbines and Power

Spray shadowgraphy under superheated and supercritical injection conditions

2020

Time-frequency localization of intermittent dynamics in a bistable turbulent swirl flame

Z. Yin, M. Stöhr

Journal of Fluid Mechanics

kHz-rate visualization of turbulence-flame interactions, Mutiresolution analysis, Wavelet-enhanced principle component analysis (PCA), Pattern recognition in image time series

2019

Wall temperature measurements in gas turbine combustors with thermographic phosphors

P. Nau, Z. Yin, K.P. Geigle, W. Meier

Journal of Engineering for Gas Turbines and Power

Sooting flames, surface thermometry under elevated pressure, quantification of heat loss through combustor chamber

2018

Experimental study of transient mechanisms of bistable flame shape transitions in a swirl combustor

M. Stöhr, K. Oberleithner, M. Sieber, Z. Yin, W. Meier

Journal of Engineering for Gas Turbines and Power

Quantitative analysis of flame bistability, Spectral proper orthogonal decomposition (SPOD)

2017

Responses of combustor surface temperature to flame shape transitions in a turbulent bistable swirl flame

Z. Yin, P. Nau, W. Meier

Experimental Thermal and Fluid Science

kHz-rate surface thermometry and flame visualization, phosphor thermometry, boundary conditions on combustion stability

2016

Plasma flow reactor studies of H2/O2/Ar kinetics

N. Tsolas, K. Togai, Z. Yin, K. Frederickson, R.A. Yetter, W.R. Lempert, I.V. Adamovich

Combustion and Flame

Plasma flow reactor, in-situ and ex-situ diagnostics, plasma kinetics

2015

Time-resolved radical species and temperature distributions in an Ar-O2-H2 mixture excited by a nanosecond pulse discharge

Z. Yin, Z. Eckert, I.V. Adamovich, W.R. Lempert

Proceedings of the Combustion Institute

Two-photon laser-induced fluorescence (TALIF), quantitative species concentrations and gas temperature, 1-D plasma kinetics modeling

2014

Effects of signal corrections on measurements of temperature and OH concentrations using laser-induced fluorescence

Z. Yin, C.D. Carter, W.R. Lempert

Applied Physics B

Quantitative OH laser-induced fluorescence (LIF), beam attenuation, signal trapping, LIF modeling

2013

Measurements of temperature and hydroxyl radical generation/decay in lean fuel-air mixtures excited by a repetitively pulsed nanosecond discharge

Z. Yin, A. Montello, C.D. Carter, W.R. Lempert, I.V. Adamovich

Combustion and Flame

Picosecond coherent anti-stokes Raman spectroscopy (CARS), quantitative OH laser-induced fluorescence (LIF), nanosecond pulse discharge, plasma-assisted oxidation

2012

Measurements and kinetic modeling of energy coupling in volume and surface nanosecond pulse discharges

K. Takashima, Z. Yin, I.V. Adamovich

Plasma Sources Science and Technology

Volumetric and surface discharges, plasma imaging, plasma kinetic modeling


About

bio

Where I have been

I grew up in the now (in)famous city of Wuhan in China and studied Naval Architecture at the Huazhong University of Science and Technology there. After that, I was trained as an experimentalist in laser spectroscopy and plasma physics at the Nonequilibrium Thermodynamics Laboratory at the Ohio State University in Columbus, OH, USA. I’m currently a research scientist at the German Aerospace Center (DLR) in Stuttgart, Germany. With my colleagues at the Institute of Combustion Technology at DLR, I’m working on new combustion systems that could handle low-carbon, sustainable fuels for both stationary gas turbines and aircraft engines.

What I am interested in

As a latecomer to programming, I only started learning Python in my very late 20s, mostly to replace the costly Matlab for processing experimental data. Programming and data science have since grown on me and have kept me busy in front of the computer during most of my free time (which have become especially excessive in this pandemic).

I’m also into:

  • Tinkering with web dev frameworks (Django, Plotly/Dash, Jekyll, Bootstrap)
  • Reading novels (Harper Lee, Kurt Vonnegut, David Mitchell, Robert A. Heinlein, Ted Chiang, Kazuo Ishiguro, and J.K. Rowling)
  • Jogging in the woods while listening to podcasts
  • Hiking the GR trails
  • Learning to draw with pen, brush and ink
  • Learning new languages (Japanese and French at the moment)

So if anything piques your interest on this site, don’t hesitate to get in touch!