Article
Thermodynamics
Iacopo Tirelli, Andrea Ianiro, Stefano Discetti
Summary: We present a novel end-to-end approach to enhance the resolution of Particle Image Velocimetry (PIV) measurements. Our method utilizes information from different snapshots to obtain high-resolution flow fields and uncertainty estimations with minimal user intervention.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2023)
Article
Mechanics
Chuangxin He, Peng Wang, Yingzheng Liu, Lian Gan
Summary: Sequential data assimilation (DA) was applied to the three-dimensional flow fields of a circular jet measured by tomography particle image velocimetry (tomo-PIV). The study focused on analyzing flow enhancement and pressure determination from volumetric flow measurement data. The results showed that sequential DA reduced errors, improved the divergence condition of the flow fields, and enhanced the dynamical features of vortical structures.
Article
Engineering, Multidisciplinary
Yanhua Liu, Xiaojing He, Yuncheng He, Dacan Zhang, Hongyao Chen, Jiyang Fu
Summary: This study investigates the surface wind pressure distribution and wake flow of finite blunt plates with different leading edge geometries. The results show that the wind pressure distribution is greatly influenced by the leading edge geometry. A larger leading edge angle leads to a decrease in the peak values of the mean pressure coefficient and peak suction pressure coefficient, while increasing the peak value of the r.m.s pressure coefficient. The wake flow analysis reveals that an increase in leading edge angle results in a longer low-velocity recirculation zone in the wake, accompanied by a more unstable and complex flow field.
Article
Mechanics
Peng Xu, Chun-yu Guo, Yang Han, Xiao-jun Bi, Yun-fei Kuai, Yi-wei Fan
Summary: The shaft bracket, as the supporting structure of a ship shafting, has a significant impact on the hydrodynamic performance of the ship. It influences the wake field in the entire installation space, with the outer bracket arm having a more significant influence than the inner bracket arm. Flow separation occurs at the outer bracket arm. The shaft bracket improves turbulent kinetic energy and fluctuation velocity but can have adverse effects on the propeller if the installation angle is too large.
Article
Engineering, Biomedical
Guilherme Miotto, Kerstin Thiemann, Markus Rombach, Roland Zengerle, Sabrina Kartmann
Summary: This article presents a method based on holographic PIV/PTV for accurately measuring low flow rates in medical applications. The method is simple and can measure flow rates within the range of a few nL/min.
BIOMEDICAL ENGINEERING-BIOMEDIZINISCHE TECHNIK
(2023)
Article
Mechanics
Qigang Chen, Yanchong Duan, Qiang Zhong, Zhongxiang Wang, Lei Huang
Summary: The accurate determination of instantaneous wall shear stress (WSS) has been a focus of research, with investigations using direct numerical simulation data and experimental data to explore influencing factors and correction methods. The proposed correction method significantly improves the accuracy of statistics of instantaneous WSS determined from near-wall velocity measurements.
Review
Engineering, Marine
Changdong Yu, Xiaojun Bi, Yiwei Fan
Summary: Deep learning technique has made significant progress in fluid mechanics by extracting powerful features from complex and massive fluid data. This paper provides a comprehensive review of deep learning-based methods for fluid motion estimation and velocity field super-resolution reconstruction. The commonly used fluid motion estimation approach, particle image velocimetry (PIV) algorithm, is investigated here. Additionally, the paper discusses future research directions.
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
Thermodynamics
Muhammad Ikhlaq, Yasir M. Al-Abdeli, Mehdi Khiadani
Summary: The study found that high swirl conditions typically lead to upstream vortex breakdown, but do not coincide with the appearance of any downstream recirculation zones that stabilise onto the impingement plane.
APPLIED THERMAL ENGINEERING
(2021)
Article
Engineering, Mechanical
Jason Appelbaum, Duncan Ohno, Ulrich Rist, Christoph Wenzel
Summary: The study applies unsteady 3D particle tracking velocimetry (PTV) data as an inlet boundary condition in direct numerical simulation (DNS) for a zero pressure gradient (ZPG) turbulent boundary layer (TBL) flow over a flat plate. The agreement between experimental flow field and simulated counterpart with a hybrid 3D inlet region is investigated. Results show that turbulent structures with a characteristic length on the order of one average tracer particle nearest neighbor radius or greater are well reproduced downstream of the hybrid inlet, while smaller turbulent scales can quickly redevelop previously unresolved turbulent energy.
EXPERIMENTS IN FLUIDS
(2021)
Article
Engineering, Environmental
Qichao Zhou, Jian Liu, Li Liu
Summary: To achieve fast solution of mine flow field, a prediction model based on convolutional neural network (CNN) is proposed. The model utilizes the geometry flow field simulated by lattice Boltzmann method (LBM) as training data, and uses CNN to extract the basic characteristics of the flow field and establish the mapping relationship between geometric boundary and flow field. The accuracy and reliability of the CNN model for predicting mine flow field are proven through LBM simulation experiments and PIV test experiments.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Mechanics
Yuchen Song, Rui Xu, Yu Song, Yun Long, Junlian Yin, Dezhong Wang
Summary: This study investigates the effect of non-uniform inflow on the performance of a reactor coolant pump. It is found that non-uniform inflow leads to variations in head, efficiency, cavitation, and vibrations, which may be caused by the non-uniform pressure field. Additionally, the study reveals the presence of two large-scale vortices in the non-uniform inflow and analyzes the characteristics and changes in non-uniformity using statistical methods.
Article
Engineering, Electrical & Electronic
Enrique Alvarez Vazquez, Daniel Ewert, Dave Jorgenson, Michael Sand
Summary: This article analyzes and characterizes the uncertainty in noninvasive blood pressure measurements and develops a computer-based simulation to simulate this uncertainty. The results show that the simulated uncertainty is consistent with the upper limits observed in a human-subject experiment.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Engineering, Multidisciplinary
Mohammed El-Adawy, M. R. Heikal, A. Rashid A. Aziz, Rasheed Adewale Opatola
Summary: There is an increasing demand for better understanding of the combustion processes in modern engines, with large-scale intake generated flow structures having a significant effect on combustion behavior and being widely studied. Traditional tools for assessing in-cylinder flow behavior include steady-state flow rigs and research engines with optical access. Recent developments in stereoscopic particle image velocimetry for engine flow measurements are presented and discussed.
ALEXANDRIA ENGINEERING JOURNAL
(2021)
Article
Engineering, Multidisciplinary
Suna Guo, Cuihong Sun, Shan Zhang, Libin Cheng, Xiying Wang, Fan Wang
Summary: By conducting experiments and CFD simulations, researchers investigated the flow field of gas turbine flowmeters and identified the key factors affecting their performance, including the length of the upstream flow conditioner, the ratio of hub radius to housing inner radius, the blade tip clearance, and the blade overlap degree. Based on these findings, seven optimization schemes were proposed and evaluated using the average meter factor-pressure error (Em-n). The results showed a reduction in the average meter factor-pressure error from 2.23% to 0.95% after optimization.
Article
Computer Science, Interdisciplinary Applications
Sean M. Rothenberger, Jiacheng Zhang, Melissa C. Brindise, Susanne Schnell, Michael Markl, Pavlos P. Vlachos, Vitaliy L. Rayz
Summary: We present a model to estimate the bias error of 4D flow MRI velocity measurements, accounting for intra-voxel velocity distribution and partial volume effects. The model accurately estimates the bias error in voxels not affected by partial volume effects, and can help plan 4D flow MRI scans.
IEEE TRANSACTIONS ON MEDICAL IMAGING
(2022)
Article
Engineering, Multidisciplinary
Jiacheng Zhang, Sayantan Bhattacharya, Pavlos P. Vlachos
Summary: This work presents a method to estimate the uncertainty of pressure fields reconstructed from PIV/PTV measurements. The method propagates the uncertainty of the velocity vectors through the pressure reconstruction. The method has been validated through tests on synthetic velocity fields and experimental flow fields, showing high accuracy in capturing the effects of velocity noise, autocorrelation, and pressure gradient integration methods on pressure errors.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Biomedical
Jiacheng Zhang, Sean M. Rothenberger, Melissa C. Brindise, Michael Markl, Vitaliy L. Rayz, Pavlos P. Vlachos
Summary: This study introduces a novel method for estimating wall shear stress (WSS) using 4D flow MRI, which improves the accuracy of WSS estimation by correcting velocity gradient estimation. The method was tested on synthetic and in vivo data, and compared to the state-of-the-art method. The proposed method showed significant improvement in WSS accuracy and its potential for predicting cardiovascular diseases.
ANNALS OF BIOMEDICAL ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Javad Eshraghi, Jean-Christophe Veilleux, Galen Shi, David Collins, Arezoo M. Ardekani, Pavlos P. Vlachos
Summary: Cavitation is an undesirable phenomenon that may occur in certain types of autoinjectors, potentially causing damage to the device container and protein drug molecules. By analyzing the potential effects of cavitation on autoinjectors, it was found that design parameters have an impact on the severity of cavitation, providing valuable data insights.
PHARMACEUTICAL RESEARCH
(2022)
Article
Engineering, Biomedical
Melissa C. Brindise, Kevin Buno, Luis Solorio, Pavlos P. Vlachos
Summary: We propose a novel automated method for identifying tissue layers in histology images. The method incorporates coarse boundary identification and refinement steps to accurately segment different layers. Experimental results show that our method is robust across different histology stains.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Biomedical
Brian H. Jun, Adib Ahmadzadegan, Arezoo M. Ardekani, Luis Solorio, Pavlos P. Vlachos
Summary: This study presents a feature-based cell tracking algorithm that can automatically detect and track cells in time-lapse images. By using advanced image processing techniques and adaptive thresholding, the algorithm can handle cell feature changes and achieves high detection and tracking accuracy.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Biomedical
Mario de Lucio, Yu Leng, Atharva Hans, Ilias Bilionis, Melissa Brindise, Arezoo M. Ardekani, Pavlos P. Vlachos, Hector Gomez
Summary: Subcutaneous injection of therapeutic monoclonal antibodies (mAbs) is a rapidly growing field in the pharmaceutical industry. This study presents a large-deformation poroelastic model to understand high-dose, high-speed subcutaneous injection. The anisotropy of subcutaneous tissue and the multi-layer structure of the skin tissue are considered. The impact of handheld autoinjectors on injection dynamics for different patient forces is analyzed. The simulations highlight the importance of the large deformation approach in modeling large injection volumes and provide insights into the mechanics and transport processes in subcutaneous injections of mAbs.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Patrick A. Giolando, Kelsey Hopkins, Barrett F. Davis, Nicole Vike, Adib Ahmadzadegan, Arezoo M. Ardekani, Pavlos P. Vlachos, Joseph V. Rispoli, Luis Solorio, Tamara L. Kinzer-Ursem
Summary: Implantable, bioresorbable drug delivery systems provide a patient-tailored drug dosage with increased patient compliance. Mechanistic mathematical modeling accelerates the design of release systems by predicting physical anomalies and short- and long-term drug release profiles. This study investigates the impact of various parameters on drug release and offers new insight into the design process for tailored release systems.
ADVANCED MATERIALS
(2023)
Article
Pharmacology & Pharmacy
Xiaoxu Zhong, Jean-Christophe Veilleux, Galen Huaiqiu Shi, David S. Collins, Pavlos Vlachos, Arezoo M. Ardekani
Summary: In recent years, significant progress has been made in the studies of spring-driven autoinjectors, leading to an improved understanding of its interactions with tissue and therapeutic proteins. Simulation tools have enhanced the prediction of performance, while this paper addresses critical hydrodynamic considerations and presents a framework for optimizing design. This work is valuable to the pharmaceutic industry as it provides insights into device development and improving patient outcomes.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2023)
Article
Mechanics
Adib Ahmadzadegan, Harsa Mitra, Pavlos P. Vlachos, Arezoo M. Ardekani
Summary: We propose a novel method called particle image rheometry (PIR) to measure the rheological properties of fluids using the Brownian motion of suspended particles. PIR estimates the particle ensemble mean square displacement (MSD) from the temporal evolution of the displacement probability density function (PDF). Our evaluations show that PIR achieves a lower error than existing methods, with less than 1% error in passive microrheology measurements.
JOURNAL OF RHEOLOGY
(2023)
Article
Cardiac & Cardiovascular Systems
Brett Meyers, Jonathan Nyce, Jiacheng Zhang, Lowell H. Frank, Elias Balaras, Pavlos P. Vlachos, Yue-Hin Loke
Summary: The study aimed to determine whether a novel, vendor-independent Doppler velocity reconstruction (DoVeR) could measure right ventricular intracardiac flow in conventional echocardiography of repaired tetralogy of Fallot (RTOF) patients. The results showed that DoVeR could detect increased vorticity and diastolic flow energy loss (FEL) in RTOF patients, and these measures correlated with ventricular function. The importance of this study lies in the potential of DoVeR to provide serial evaluation of abnormal flow dynamics in RTOF patients.
JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY
(2023)
Article
Biology
Mary K. Salcedo, Brian H. Jun, John J. Socha, Naomi E. Pierce, Pavlos P. Vlachos, Stacey A. Combes
Summary: Research shows that the circulation system, respiration system, and nervous system of insects extend into their wings, playing a critical role in supplying nutrients and maintaining wing function. High-speed fluorescent microscopy and particle tracking reveals dynamic flow patterns in every vein of grasshopper wings, with three different flow behaviors: pulsatile, aperiodic, and leaky. Study of the wing circulatory system provides valuable insights into the hemodynamics necessary for sustaining wing health and insect flight.
COMMUNICATIONS BIOLOGY
(2023)
Article
Computer Science, Interdisciplinary Applications
Sean M. Rothenberger, Neal M. Patel, Jiacheng Zhang, Susanne Schnell, Bruce A. Craig, Sameer A. Ansari, Michael Markl, Pavlos P. Vlachos, Vitaliy L. Rayz
Summary: We propose an automatic segmentation method for 4D flow MRI based on SDM velocity. The SDM velocity quantifies the net flow effects in each voxel, and vessel segmentation is performed using an F-test. We compare the SDM algorithm with PCD and CNN segmentation methods, and the results demonstrate its robustness and accuracy in identifying vessel surfaces.
IEEE TRANSACTIONS ON MEDICAL IMAGING
(2023)
Article
Multidisciplinary Sciences
Jiacheng Zhang, Melissa C. Brindise, Sean M. Rothenberger, Michael Markl, Vitaliy L. Rayz, Pavlos P. Vlachos
Summary: This study evaluates and applies a multi-modality approach to improve blood flow measurements and hemodynamic analysis in cerebral aneurysms using 4D flow MRI. The method reconstructs the flow field and calculates the pressure using sparse representation, leading to enhanced accuracy of the measurements.
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2022)