Article
Engineering, Chemical
Yingchun Wu, Xinhao Wang, Dongyan Xu, Xuecheng Wu
Summary: Synthetic aperture rainbow refractometry (SARR) is a method proposed for characterizing the optical properties of droplets and sprays at a long stand-off distance. It utilizes multiple crossing laser beams and color imaging to synthesize rainbow signals and enlarge the aperture of the imaging system. The method has been validated with simulations and experiments, and shows great potential for large scale industrial applications.
Article
Optics
Wenmin Peng, Can Li, Tianchi Li, Linbin Huang, Ning Li, Chunsheng Weng
Summary: This study simulated and experimentally evaluated the effect of signal noise on the inversion accuracy of global rainbow signals of droplets with different size distributions. It used a local minimum-based algorithm for parameter retrieval and empirical mode decomposition for denoising. The results showed that the inversion algorithm had the highest accuracy for noise-free signals, while the empirical mode decomposition effectively reduced the errors of droplet size and refractive index even under low signal-to-noise ratios. The experimental results further confirmed the feasibility and effectiveness of the proposed processing procedures.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2023)
Article
Optics
X. I. N. H. A. O. Wang, Y. I. N. G. C. H. U. N. Wu, D. O. N. G. Y. A. N. Xu, B. O. T. O. N. G. Wen, Q. I. M. E. N. G. Lv, X. U. E. C. H. E. N. G. Wu
Summary: This work proposes a synthetic aperture rainbow refractometry (SARR) by synthesizing rainbow signals of the same droplet with dual-wavelength laser beams to increase the aperture of rainbow refractometry. The feasibility and accuracy of SARR are successfully demonstrated for measuring droplet refractive index and size.
Article
Optics
M. F. B. Stodt, T. Wriedt, J. Kiefer, U. Fritsching
Summary: This study investigates the application of global rainbow refractometry to sprays with droplets as small as 1 - 30 µm in diameter, evaluating the influence of varying droplet size distributions and refractive indexes on the global rainbow. The results suggest that GRR experiments in polydisperse applications should be accompanied with an accurate sizing technique.
JOURNAL OF MODERN OPTICS
(2021)
Article
Optics
Qimeng Lv, Yingchun Wu, Xuecheng Wu
Summary: Rainbow refractometry is used to measure the temperature and size of transparent spherical particles. However, there are limitations in its application when heating and cooling droplets, as the measured temperature is not the average, surface, or core temperature of the droplet. This study exploits the technique to determine the surface temperature of droplets by measuring the surface tension through detecting the evolution of interference fringes. The relationship between surface tension and temperature enables the study of the surface temperature of evaporating droplets over time. The capabilities and limitations of rainbow refractometry are verified by comparing the directly measured droplet temperature values with the surface temperature.
Article
Optics
Can Li, Wenmin Peng, Yang Kang, Xudong Fan, Xiaolong Huang, Ning Li, Chunsheng Weng, Cameron Tropea
Summary: Rainbow refractometry has been developed for spray measurement applications, allowing simultaneous measurement of refractive index and droplet size. This study investigates the feasibility and accuracy of using incomplete rainbow signals for measurement. The newly defined dimensionless signal partial ratio (SPR) quantifies the degree of incompleteness. Simulation and inversion experiments were conducted, and the results showed that inversion using signal fitting is more accurate than using specific characteristic points. Laboratory experiments also verified these findings. For SPR <= 1, rainbow refractometry achieves errors within 6 x 10-4, 3% for monodisperse droplets and 2 x 10-4, 8% for spray droplets in terms of refractive index and size.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Environmental Sciences
Kimberly M. Carlson, Camilo Mora, Jinwen Xu, Renee O. Setter, Michelle Harangody, Erik C. Franklin, Michael B. Kantar, Matthew Lucas, Zachary M. Menzo, Daniele Spirandelli, David Schanzenbach, C. Courtlandt Warr, Amanda E. Wong, Steven Businger
Summary: Rainbows contribute to human wellbeing by providing a connection to nature, but their distribution is likely to be altered by climate change. Research suggests that by 2100, there could be a 4.0-4.9% increase in annual rainbow-days globally, with regional variations. This highlights the significant impact of climate change on rainbow occurrence and the need for attention and mitigation.
GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS
(2022)
Article
Engineering, Chemical
Can Li, Qimeng Lv, Ning Li, Yingchun Wu, Xuecheng Wu, Chunsheng Weng, Cameron Tropea
Summary: There is significant interest and demand for the multi-parameter characterization of colloidal droplets. However, optical in-situ characterization of such droplets poses a challenge due to their heterogeneous and multi-scale nature. This study proposes an analytical model for dual-wavelength extinction rainbow refractometry, which allows for the simultaneous measurement of inclusion concentration, particle size, refractive index, and droplet diameter. Validation experiments demonstrate the effectiveness of this method, and the measurement errors and limitations are analyzed.
Article
Engineering, Multidisciplinary
Zhisong Wang, Qingming Liu, Lidan Yue, Dan Wang, Qi Jing, Changqi Liu, Zongling He, Zhou Yang
Summary: This paper establishes a multi-wavelength detection model based on the OptQuest nonlinear programming algorithm to study the particle size distribution (PSD) of spherical particles. An experiment is designed to verify the reliability of the system. The selection of detection wavelength greatly affects the results of PSD inversion, and choosing the wavelength at the peak of the extinction coefficient curve of appropriate particle size minimizes the relative error of PSD parameters. Both simulation and experimental results indicate that the five-wavelength method has the highest testing accuracy.
Article
Multidisciplinary Sciences
Guangmei Ji, Huizhe Chen, Yuping Zhang, Jing Xiang, Yaliang Wang, Zhigang Wang, Defeng Zhu, Yikai Zhang
Summary: The study showed that the leaf surface characteristics of hairy-leaved rice and glabrous rice significantly impacted the behavior of canopy droplets. Hairy-leaved rice retained more large-sized droplets, while glabrous rice retained more small-sized droplets.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Chemical
Yingchun Wu, Qimeng Lv, Xuecheng Wu, Xinhao Wang, Linghong Chen, Kefa Cen
Summary: The oscillation of micron-sized liquid droplets can be measured using time-resolved rainbow refractometry to determine surface tension and viscosity. The method shows potential for improving experimental validation and reducing measurement errors, with relative errors of less than 5% for surface tension and 10% for viscosity.
Article
Chemistry, Physical
Melisa Nyakuchena, Cory Juntunen, Peter Shea, Yongjin Sung
Summary: The refractive index is a significant optical property for measuring light scattering and label-free imaging, and various methods have been developed to characterize different sample types. This paper demonstrates a technique using synthetic phase microscopy (SPM) and least-squares fitting to measure the refractive index of homogeneous microspheres and liquids in the short-wave infrared range. The method was applied to determine the refractive index dispersion of different polymer and glass microspheres, as well as microscopy mounting media in the SWIR range of 1100-1650 nm.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Li Can, Lu Qimeng, Wu Yingchun, Wu Xuecheng, Gao Xiang, Cen Kefa
Summary: A local minimabased general inversion algorithm was proposed and tested on standard and global rainbow signals, with promising results indicating its effectiveness under different conditions. The algorithm is based on complex angular momentum theory with correction coefficients and iterative sequential quadratic programming.
LASER & OPTOELECTRONICS PROGRESS
(2021)
Article
Thermodynamics
Qimeng Lv, Yingchun Wu, Xinhao Wang, Lei Zeng, Xuecheng Wu
Summary: This study experimentally investigates the evaporation characteristics of fuel droplets under the combined effects of ambient pressure, temperature, droplet size, and spacing. The results show that the evaporation rate of droplets is influenced by both ambient conditions and droplet interactions. Furthermore, the study reveals the correlations between Nusselt and Sherwood numbers through parametric analysis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Zhaojing Ni, Camille Hespel, Kai Han, Fabrice Foucher
Summary: The evaporation behavior of binary droplets consisting of ethanol and heptane was studied experimentally and through simulation. The study found that the heavier component preferentially evaporates when the lighter component dominates the liquid mixture. The refractive index of the droplets is influenced by temperature and composition, and a linear relationship between the refractive index gradient and the deviations from the center refractive index was proposed. The accuracy of a non-ideal equilibrium model for predicting the diameter, temperature, and concentration of binary droplets was validated for the first time.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2022)
Article
Engineering, Mechanical
Budi Rochmanto, Hari Setiapraja, Ihwan Haryono, Siti Yubaidah
Summary: This study calibrates a turbine flowmeter for compressed natural gas (CNG) application by using air as a substitute and simulating the kinematic viscosity property of CNG. The research shows that by using air instead of CNG, the flowmeter can achieve accurate measurements with a measurement uncertainty of less than 1%.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Mona Mary Varghese, Chaithanya P. Devan, Samiksha M. Masram, Teja Reddy Vakamalla
Summary: This work investigated the influence of particle shape on fluidization behavior at different inlet superficial gas velocities. The experiments were conducted using a laboratory-scale 3D circular fluidized bed column with Geldart D particles of various shapes. The results showed that non-spherical particles had lower minimum fluidization velocities and higher bed expansion compared to spherical particles. Particle shape significantly affected solids holdup, with spherical particles exhibiting higher solids holdup at the same superficial velocity. Frequency domain analysis of pressure signals using Fast Fourier Transform (FFT) and Power Spectral Density (PSD) revealed flow regime transitions associated with changes in particle shape.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Ruiming Yu, Yunyan Ma, Kuaile Liu, Xiangyu Liu
Summary: A single-seat control valve with stable flow regulation is researched and designed to address technical problems such as unstable flow at small openings and uneven force on the valve core. The mechanical and flow characteristics, as well as thermal stress, are analyzed through simulations and tests. The results show that the designed valve meets the requirements.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Alcemir Costa de Souza, Ewerton Emmanuel da Silva Calixto, Fernando Luiz Pellegrini Pessoa, Valeria L. da Sila, Luiz Octavio Vieira Pereira
Summary: This study proposes a simple CO2 meter for accurately measuring the CO2 content in Brazilian pre-salt production flows. By analyzing the pressure change during a heating assay of an imprisoned sample, the proposed meter is capable of identifying the mixture properties under different CO2 levels.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Mehdi Asadi, S. Abbas Hosseini, Kaveh Ahangari
Summary: Due to technical issues with bottom intake racks, porous intakes made of rock, gravel, or sand can be a viable alternative. This study used an experimental model to assess the performance of porous bottom intakes (PBI) and examined the impacts of various parameters such as channel slope, grain size distribution of the porous media, intake structure geometry, and water depth in the channel on diverted flow rates during sediment-free flow. The study also compared the performance of one-sided and three-sided PBI models under the same conditions. The findings suggest that a slope of 1% yields higher discharge coefficient and diverted flow compared to a slope of 1.68%, and three-sided PBI models outperform one-sided models in terms of flow rate. A formula utilizing nonlinear multivariate regression, experimental data, and dimensional analysis was proposed for calculating the discharge coefficient of PBI, with a high accuracy rate of over 95%.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)