Article
Energy & Fuels
Andreas Unterberger, Fabio J. W. A. Martins, Khadijeh Mohri
Summary: An integrated approach is presented for tomographic reconstruction of multiple scalar fields in premixed non-sooting reactive flow. Different physical quantities are measured and combined to analyze the combustion process in premixed turbulent flames. The proposed method combines chemiluminescence signals and deflection data from a schlieren tomography setup to solve the 3D tomographic inverse problem. The technique is applied to both synthetic and experimental measurement data to test its consistency and sensitivity.
Article
Optics
Lei Han, Qiang Gao, Bo Li, Ming Li, Dayuan Zhang, Xuesong Bai, Zhongshan Li
Summary: This study presents a method for simultaneously measuring velocity and concentration using femtosecond laser-induced chemiluminescence. By measuring the decay of CN radical fluorescence and using two-dimensional imaging, the simultaneous measurement of velocity and mixture fraction can be achieved.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Chemistry, Physical
Zhonghua Wu, Yunpeng Liu, Xueqing Xing, Lei Yao, Zhongjun Chen, Guang Mo, Lirong Zheng, Quan Cai, Hao Wang, Jiajun Zhong, Yuecheng Lai, Lixiong Qian
Summary: This study presents a novel setup for combined small-angle X-ray scattering/X-ray diffraction/X-ray absorption fine structure (SAXS/XRD/XAFS) to obtain multiple structural information simultaneously. The setup employs different detectors for measuring SAXS, XRD, and XAFS signals. The use of a minitype diamond detector coupled to a SAXS beamstop enables compatible measurements of scattering and absorption signals without mechanical switching. Two-way and high-frequency sampling strategies are implemented to shorten non-counting time and improve measurement efficiency and signal-to-noise ratio. The rotation of the monochromator is the only mechanical movement during measurements, allowing for time resolutions within seconds. This combined setup offers the potential to track the structure evolution in complex fluids.
Review
Engineering, Multidisciplinary
Shwetank Krishna, Gerhard Thonhauser, Sunil Kumar, Asad Elmgerbi, Krishna Ravi
Summary: This paper reviews the basic principles and working mechanism of ultrasound velocity profiling combined with pressure differential measurement, and discusses the factors affecting its performance. The experimental procedure and data processing process are described, and the published literature on the UVP-PD method is briefly summarized. Finally, the prospects and recommendations for the application and improvement of this tool are highlighted.
Article
Engineering, Multidisciplinary
Seong-Ho Jin, Gyung-Soo Kim
Summary: Planar temperature images were obtained using laser Rayleigh scattering to determine temperature distribution in a constant volume combustion chamber. Burning velocities were measured from pressures and flame surface area from Rayleigh scattering images. The technique allows simultaneous measurement of temperature and burning velocity using a single-shot laser light.
Article
Optics
Kharthik Chakravarthy, Laurent M. Le Page, Benjamin A. O. Williams
Summary: This paper demonstrates the application of polarized-depolarized Rayleigh scattering (PDRS) as a simultaneous mixture fraction and temperature diagnostic for non-reacting gaseous mixtures. The use of PDRS shows promise in a range of applications outside combustion, such as in aerodynamic cooling technologies and turbulent heat transfer studies. This work demonstrates the feasibility and potential of PDRS in obtaining simultaneous temperature and mixture fraction visualization in gaseous mixtures.
Article
Physics, Fluids & Plasmas
Jingkai Jiang, Caleb Richards, Igor Adamovich, Peter J. Bruggeman
Summary: This letter reports the spatially resolved measurements of vibrationally excited N-2 in the effluent of an atmospheric pressure plasma jet using molecular beam mass spectrometry (MBMS). The results show the capability of MBMS to accurately measure vibrationally excited species near interfaces.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Thermodynamics
R. Clavenna, L. Araneo
Summary: The study proposes a novel non-intrusive infrared technique called Twin Background Subtraction (TBS) to simultaneously measure the thickness and temperature of a semi-transparent thin film. The technique utilizes the mid-wave IR emission from the film and the radiation attenuation by the same film of the emission from two backgrounds at different temperatures. The study discusses the theoretical and experimental aspects of the TBS method and its dependence on different parameters and fluid properties.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2023)
Article
Energy & Fuels
Marco Lubrano Lavadera, Christian Brackmann, Gianluca Capriolo, Torsten Methling, Alexander A. Konnov
Summary: Experimental results on the adiabatic laminar burning velocities and post-flame NO mole fractions of neat and blended ethanol and n-heptane premixed flames demonstrate that the addition of ethanol increases the burning velocity and reduces NO formation. These findings are crucial for the development and optimization of chemical kinetic models.
Article
Energy & Fuels
Jingyu Zhu, Conghui Shan, Keiya Nishida, Wuqiang Long, Dongsheng Dong
Summary: This study examines the two-phase flow characteristics of transient Diesel spray using optical diagnosis techniques and numerical simulation methods, providing insights into the spray structure and turbulent mixing features. Additionally, an improved velocity predicting model accounting for spatial variation is developed for enhanced understanding of the flow dynamics.
Article
Engineering, Mechanical
Florian Burkle, Jurgen Czarske, Lars Buettner
Summary: This study combines Laser Doppler Velocity Profile Sensor (LDV-PS) with Laser-Induced Fluorescence (LIF) to solve the problem of simultaneous non-intrusive temperature and velocity measurements in flows. In an air flow experiment, relative velocity uncertainties of 0.4% and temperature uncertainties of 0.24°C with a spatial resolution of 10 μm are achieved. The method has the potential to be applied in various thermal flows and improve the energy efficiency of microfluidic devices.
FLOW MEASUREMENT AND INSTRUMENTATION
(2022)
Article
Chemistry, Physical
James D. Fletcher, Lucia Lanfri, Grant A. D. Ritchie, Gus Hancock, Meez Islam, Graham Richmond
Summary: Time-resolved observations show the formation of vibrationally excited NO X (2)pi (v ') following collisional quenching of NO A (2)sigma(+) (v = 0) by NO X (2)pi (v = 0). The fast production rate is consistent with direct formation from the quenching of the electronically excited NO A state, while the slow component's formation rate depends on NO pressure. A reservoir state formed by quenching of NO A (2)sigma(+) (v = 0) is proposed to explain the observations, with evidence suggesting it is the first electronically excited state of NO, a (4)pi. The rate constant for quenching the a (4)pi state by NO is measured, and the fraction of self-quenching collisions of NO A (2)sigma(+) (v = 0) leading to NO a (4)pi formation is estimated.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Environmental Sciences
Marcel Zauner-Wieczorek, Martin Heinritzi, Manuel Granzin, Timo Keber, Andreas Kurten, Katharina Kaiser, Johannes Schneider, Joachim Curtius
Summary: In this study, the first airborne measurements of ambient ions in the free troposphere and lower stratosphere above Europe were conducted using a high-resolution atmospheric pressure interface time-of-flight mass spectrometer (HR-APi-TOF-MS). The measured ions, including nitrate and hydrogen sulfate, showed an increasing count rate with higher altitudes. The study also inferred the number concentration of gaseous sulfuric acid from the count rates of core ions. During the transit through a mixed-phase cloud, an event of enhanced ion count rates and aerosol particle concentrations, largely attributed to nitrate ions and particles, was observed.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Environmental Sciences
Marti Sanchez-Juny, Soledad Estrella, Jorge Matos, Ernest Blade, Eduardo Martinez-Gomariz, Enrique Bonet Gil
Summary: This study investigates the flow velocity distribution in a steeply sloping stepped spillway without sidewalls using a physical model and bubble image velocimetry (BIV) technique. The results show relatively good agreement between the free-surface velocity and the air-water interfacial velocity, as well as reasonable agreement between the velocity profiles along the normal to the pseudo-bottom and the air-water interfacial velocity profiles in the skimming flow region.
Article
Cardiac & Cardiovascular Systems
Patrick Winter, Kristina Andelovic, Thomas Kampf, Jan Hansmann, Peter Michael Jakob, Wolfgang Rudolf Bauer, Alma Zernecke, Volker Herold
Summary: Wall shear stress (WSS) and pulse wave velocity (PWV) are important parameters for blood flow in the vessel wall, but are challenging to measure simultaneously with flow-sensitive phase-contrast cardiovascular magnetic resonance (CMR). A flexible reconstruction framework was used in this study to quantify both PWV and WSS in the murine aortic arch from the same 4D flow measurement in only 35 min, improving the analyses and information content of in vivo measurements.
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
(2021)
Article
Chemistry, Physical
Michelle L. Warter, Carolyn E. Gunthardt, Wei Wei, George C. McBane, Simon W. North
JOURNAL OF CHEMICAL PHYSICS
(2018)
Article
Chemistry, Physical
C. E. Gunthardt, C. J. Wallace, G. E. Hall, R. W. Field, S. W. North
JOURNAL OF PHYSICAL CHEMISTRY A
(2019)
Article
Optics
Joshua D. Winner, Feng Pan, Madison H. McIlvoy, Rodney D. W. Bowersox, Simon W. North
Article
Chemistry, Physical
Colin J. Wallace, Carolyn E. Gunthardt, George C. McBane, Simon W. North
Article
Chemistry, Physical
Carolyn E. Gunthardt, Megan N. Aardema, Gregory E. Hall, Simon W. North
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Multidisciplinary Sciences
Shanyu Han, Carolyn E. Gunthardt, Richard Dawes, Daiqian Xie, Simon W. North, Hua Guo
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2020)
Article
Chemistry, Physical
Sk Samir Ahamed, Hyunsik Kim, Amit K. Paul, Niclas A. West, Joshua D. Winner, Diego A. Donzis, Simon W. North, William L. Hase
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Engineering, Multidisciplinary
Michael Pearce, Zachary Sparrow, Thabiso R. Mabote, Rodrigo Sanchez-Gonzalez
Summary: The new methodology presented in this study allows for high spatial resolution velocity measurements, increased reliability, and potential for automation. Compared to traditional methods, it offers better spatial resolution for flow displacement measurements while maintaining comparable precision and accuracy.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2021)
Article
Mechanics
B. McManamen, D. A. Donzis, S. W. North, R. D. W. Bowersox
Summary: Experimental examination was conducted to study the impact of a normal shock wave on velocity and temperature fluctuations, with results showing a closer alignment with classical linear interaction analyses (LIA) rather than contemporary theory.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Physical
Evangelia Sakkoula, Gautam Sharma, Xingan Wang, Simon W. North, David H. Parker, Wei Wei
Summary: In this study, the CO2 VUV photodissociation dynamics near 155 nm were investigated using VMI technique. Vector correlations extracted from anisotropic angular distributions indicated photodissociation mainly via the excited 2(1)A' (A) state. A trend was observed where an increase in the CO rotational state j led to a decrease in the spatial anisotropy parameter.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Megan N. Aardema, George C. McBane, Simon W. North
Summary: The rotational state distribution and vector correlations of the O-2(a (1)delta(g), v = 0) fragments from photodissociation are investigated, showing a shift to higher rotational states with decreasing wavelength and highly suppressed odd rotational state populations. Measurements agree with classical trajectory calculations but with a slightly narrower distribution. Spatial anisotropy decreases with increasing photon energy, and the v-j correlation is consistent with v perpendicular to j.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Optics
Caroline M. Loe, Joshua D. Winner, Rodrigo Sanchez-Gonzalez
Meeting Abstract
Chemistry, Multidisciplinary
Colin Wallace, Carolyn Gunthardt, Simon North
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY
(2018)
Meeting Abstract
Chemistry, Multidisciplinary
Michelle Warter, Carolyn Gunthardt, Wei Wei, George McBane, Simon North
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY
(2018)
Meeting Abstract
Chemistry, Multidisciplinary
Alex Prophet, Josh Winner, Simon North, Rodrigo Sanchez-Gonzalez
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY
(2018)