Article
Engineering, Aerospace
Diliana Friedewald
Summary: This research focuses on using systematic unsteady Reynolds-averaged Navier-Stokes simulations to study gust load analyses of transport aircraft in cruise flight conditions. The study found that amplitude effects decrease with lower Mach numbers or higher excitation frequencies. Nonlinear simulations predict lower maximum lift values and lower lift and moment derivatives compared to their linear counterparts for lower frequencies combined with large-amplitude excitations.
Article
Engineering, Mechanical
Yunqing Gu, Junjun Zhang, Songwei Yu, Chengqi Mou, Zhou Li, Chendong He, Denghao Wu, Jiegang Mou, Yun Ren
Summary: In this study, the grid irrelevance and discrete error in hydrofoil unsteady cavitation simulations were investigated using the GCI evaluation method to determine the optimal number of grids. Various turbulent viscosity correction approaches were employed to improve the turbulence model, and numerical simulations successfully captured the details of the hydrofoil cavity shape and shedding process, revealing the mechanism of hydrofoil cavitation.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Mechanics
Muhamed Albadawi, Yasser Abuouf, Samir Elsagheer, Shinichi Ookawara, Mahmoud Ahmed
Summary: Carotid artery disease, characterized by narrowed arteries due to plaque buildup, can be investigated using hemodynamic parameters. A computational fluid dynamics approach based on patient-specific models can be effectively used to diagnose and predict carotid artery stenosis, indicating potential high-risk regions.
Article
Mechanics
Joseph Amponsah, Pius Ohene Darko
Summary: This study investigates the radial velocity profiles near the impeller tip in a baffled stirred tank through experimental measurements and computational fluid dynamics (CFD) simulations. The results show that double turbine impellers generate localized turbulence, while pitched blade turbines with down-pumping produce high-intensity turbulence zones throughout the tank. The CFD simulations align closely with experimental data and provide further insight into flow patterns.
Article
Engineering, Marine
Chang-Lin Meng, Zhi-Jun Shuai, Tao Yu, Ke-Xin Ren, Jie Jian, Xi Wang, Dong-Hua Wang, Wan-You Li, Chen -Xing Jiang
Summary: In this paper, the unsteady exciting characteristics of a marine propeller influenced by the shafting whirling vibration effect are numerically studied by employing the dynamic sliding multi-region method and a Reynolds-averaged Navier-Stokes equation model. The propeller and shafting system inevitably vibrates during operation, where the multiple exciting forces can cause the shafting to rotate and whirl around different center lines at the same time. The influence mechanism of different whirling motions on the propeller exciting characteristics and propeller velocity field fluctuation are studied.
Article
Engineering, Mechanical
Dennis Fischer, Stephan von Goeldel, Georg Jacobs, Andreas Stratmann
Summary: This study examines the oil flow around a rolling point contact under limited oil volume and in dependence of oil wettability using CFD simulations. The effects of lubricant starvation at high rolling speeds are investigated, focusing on the replenishment of oil.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Clinical Neurology
Zhe Sun, Dengrong Jiang, Peiying Liu, Marco Muccio, Chenyang Li, Yan Cao, Thomas M. Wisniewski, Hanzhang Lu, Yulin Ge
Summary: This study conducted a quantitative investigation of vascular tortuosity and flow using MRI in a large cohort. The results showed significant effects of age and gender on vascular tortuosity and flow. Additionally, females demonstrated more distinct vascular changes compared to males.
FRONTIERS IN NEUROLOGY
(2022)
Article
Mathematics, Interdisciplinary Applications
Angelantonio Tafuni, Maria Grazia De Giorgi, Alessandro De Rosis
Summary: Numerical simulations of steady and unsteady viscous flows are presented using two different numerical methodologies, showing good accuracy compared to other well-established computational methods. Despite lacking key strategies commonly used in grid-based methods, such as adaptive mesh refinement, the proposed methods are able to capture relevant flow physics effectively.
COMPUTATIONAL PARTICLE MECHANICS
(2022)
Article
Mechanics
Shubing Dai, Sheng Jin
Summary: This paper investigates the temporal and spatial evolutions of critical flow under unsteady rapidly varied flow conditions. The results suggest that unsteadiness and non-hydrostatic pressure have significant effects on critical flow, while non-uniform velocity has a weak effect. Among the three models studied, the unsteady vertically averaged non-hydrostatic Serre-Green-Naghdi Equations and the unsteady vertical velocity-resolved non-hydrostatic Reynolds-averaged Navier-Stokes Equations are both reliable modeling options.
Article
Water Resources
Abbas Parsaie, Saleh Jaafer Suleiman Shareef, Amir Hamzeh Haghiabi, Raad Hoobi Irzooki, Rasul M. Khalaf
Summary: This paper explores the hydraulic properties of a new type of spillway with a circular crest through numerical investigation. Results indicate that the spillway is effective in dissipating flow energy and the flow streamlines are tangential to the curvature of the crest.
APPLIED WATER SCIENCE
(2022)
Article
Engineering, Multidisciplinary
Sohail Nadeem, Salman Akhtar, Anber Saleem, Nevzat Akkurt, Hassan Ali Ghazwani, Sayed M. Eldin
Summary: This research investigates the analysis of arterial blood flow through different stenotic regions. Four types of stenotic regions, including triangular, trapezoidal, overlapping (w-shape), and composite formations, are studied for the first time in numerical analysis. An elliptical cross-sectional artery is modeled using a cartesian coordinate system, and the governing partial differential equations are numerically solved with the Open-FOAM CFD software. The results show a high flow profile with minor disruptions near the origin of stenotic sections, and high pressure values near the sharp corners of stenotic regions. Expected irregularities in the flow profile are observed, typical of real-life stenosed artery blood flow problems.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Mechanics
Sumit Kumar, B. V. Rathish Kumar, S. K. Rai
Summary: New imaging methods have made it possible to detect unruptured abdominal aortic aneurysms. Mathematical models are needed to predict rupture and plan proper treatment for patients. Morphological parameters have been found to be correlated with the rupture mechanism, but their effects on hemodynamics-based predictions are not yet clear.
Article
Engineering, Marine
R. Doyle, T. L. Jeans, A. G. L. Holloway
Summary: This study analyzes the forces and moments on a UUV hull undergoing unsteady sway motions, using both traditional methods and hydrodynamic impulse based methods. It is found that the impulse based method provides a sensible decomposition of unsteady forces, primarily describing motion history effects, with decaying effects towards quasi-steady limit at large times or low frequencies.
Article
Engineering, Multidisciplinary
Ramon Silva Martins, Guilherme Siqueira de Aquino, Marcio Ferreira Martins, Rogerio Ramos
Summary: A detailed parametric sensitivity analysis reveals the impact of various modeling parameters on the numerically calculated profile factor of ultrasonic flow meters. It is observed that more caution is required in simulating pipe flows, especially when inferring the profile factor of ultrasonic flow measurements. Failure to properly analyze the sensitivity of simulation results to modeling parameters may lead to mistaken or distorted quantitative conclusions.
Article
Engineering, Petroleum
Hai Qu, Xiangjun Chen, Jun Hong, Yang Xu, Chengying Li, Zhelun Li, Ying Liu
Summary: Uniform proppant distribution among clusters and stages is crucial for optimizing fracturing parameters and enhancing production. This study proposes a novel method using experiments and a numerical model to evaluate proppant distribution. An artificial neural network (ANN) model is developed to predict proppant distribution within clusters. The results show that proppant distribution is generally toe-biased in a horizontal well due to pump rates, and fluid distribution significantly affects proppant distribution. The study provides insights for optimizing injection parameter design and real-time optimization.
Article
Thermodynamics
Michal Lipian, Ivan Dobrev, Fawaz Massouh, Krzysztof Jozwik
Article
Energy & Fuels
Damian Obidowski, Mateusz Stajuda, Krzysztof Sobczak
Summary: An efficient approach combining geometrical transformation with computational fluid dynamics, a multi-objective genetic algorithm, and a response surface is discussed for optimizing non-axisymmetric flow channels. This method significantly reduces problem size by solving flow in a quasi-2D section, covering a broader design space in a shorter time, and enabling optimization of large flow problems with desktop-class computers. The results show improved flow uniformity, elimination of separation zones, increased efficiency, and energy savings when applied to a scroll distributor.
Article
Energy & Fuels
Piotr Boguslaw Jasinski, Michal Jan Kowalczyk, Artur Romaniak, Bartosz Warwas, Damian Obidowski, Artur Gutkowski
Summary: This study presents numerical investigations on heat transfer and pressure drops in a channel with 30 degrees helical micro-fins, focusing on the impact of micro-fin height on heat-flow characteristics. The results show that pipes with micro-fins of heights 0.30 mm and 0.35 mm exhibit the highest heat transfer efficiency.
Article
Medicine, General & Internal
Karol Wisniewski, Bartlomiej Tomasik, Zbigniew Tyfa, Piotr Reorowicz, Ernest J. Bobeff, Ludomir Stefanczyk, Bartlomiej J. Posmyk, Krzysztof Jozwik, Dariusz J. Jaskolski
Summary: The project utilized statistical analysis and computational fluid dynamics simulations to identify the impact of 1st VPD on the late recanalization rate of ruptured intracranial aneurysms treated with coil embolization, providing valuable insights for clinical practice.
JOURNAL OF CLINICAL MEDICINE
(2021)
Article
Health Care Sciences & Services
Karol Wisniewski, Zbigniew Tyfa, Bartlomiej Tomasik, Piotr Reorowicz, Ernest J. Bobeff, Bartlomiej J. Posmyk, Marlena Hupalo, Ludomir Stefanczyk, Krzysztof Jozwik, Dariusz J. Jaskolski
Summary: The aim of the study was to identify risk factors for recanalization after coil embolization using both clinical data and CFD analysis. Statistical analysis revealed that factors such as aneurysm filling, packing density, aneurysm neck size, and complex flow pattern with multiple vortices are associated with recanalization risk. This suggests that complex flow pattern itself can be a relevant predictor for recanalization.
JOURNAL OF PERSONALIZED MEDICINE
(2021)
Article
Energy & Fuels
Piotr Wiklak, Michal Kulak, Michal Lipian, Damian Obidowski
Summary: This article discusses the experimental investigation of two turbines in a wind tunnel at various turbulence intensity levels and separation distances. It was found that increasing turbulence intensity can enhance the mixing of wake flow with undisturbed flow, enlarging the optimal wind turbine operating plateau and making the turbine performance less sensitive to tip speed ratio variations. The operation of the upstream turbine significantly influences the overall system performance.
Article
Food Science & Technology
Magdalena Gajek, Aleksandra Pawlaczyk, Krzysztof Jozwik, Malgorzata Iwona Szynkowska-Jozwik
Summary: A total of 170 whisky samples from 11 countries were analyzed for their elemental profiles. Copper was found to be an element that distinguished single malt and blended types of whisky, with higher concentrations in single malt Scotch whisky. Samples from the same brands but different bottles showed common elemental profiles. Additionally, the content of copper and manganese increased with longer aging time of Scotch whisky.
Article
Food Science & Technology
Magdalena Gajek, Aleksandra Pawlaczyk, Elzbieta Mackiewicz, Jadwiga Albinska, Piotr Wysocki, Krzysztof Jozwik, Malgorzata Iwona Szynkowska-Jozwik
Summary: The study analyzed 205 samples of whisky to distinguish between authentic and fake products based on their elemental profiles. Elements such as Mn, K, P, and S were identified as key markers for detecting whisky adulteration related to the aging process. Fake samples showed significantly lower levels of manganese, potassium, and phosphorus, while sulfur levels were higher compared to authentic samples.
Article
Materials Science, Textiles
Paulina Gilewicz, Damian Obidowski, Krzysztof Sobczak, Iwona Frydrych, Agnieszka Cichocka
Summary: In order to improve thermal resistance and comfort, the development of protective clothing packages for foundry workers is ongoing. A numerical model based on aluminized basalt fabric was developed to study heat transfer through the package. The model successfully simulated heat transfer through the protective package and allowed for determination of the main thermal properties of the tested basalt fabrics.
AUTEX RESEARCH JOURNAL
(2023)
Article
Engineering, Biomedical
Piotr Reorowicz, Zbigniew Tyfa, Damian Obidowski, Karol Wisniewski, Ludomir Stefanczyk, Krzysztof Jozwik, Michael Lee Levy
Summary: The Flow Diverter is a treatment method for fusiform aneurysms, commonly used for cerebral vascular anomalies but not for aortic aneurysms. Numerical simulation in a patient-specific model of abdominal aortic aneurysms allowed investigation and visualization of blood hemodynamics before and after stent implantation. The Flow Diverter stent significantly changed the flow pattern in the aneurysm region but did not affect blood flow to the renal arteries.
BIOCYBERNETICS AND BIOMEDICAL ENGINEERING
(2022)
Article
Thermodynamics
Emil Marchewka, Krzysztof Sobczak, Piotr Reorowicz, Damian Stanislaw Obidowski, Krzysztof Jozwik
Summary: Machines utilizing renewable energy are constantly under research to improve their efficiency. The Savonius wind turbine, equipped with deformable blades, showed a 55% increase in power coefficient compared to a conventional rigid turbine. The overset mesh approach was used to study the performance of the deformable blades rotor.
ARCHIVES OF THERMODYNAMICS
(2021)
Article
Energy & Fuels
Malgorzata Stepien, Michal Kulak, Krzysztof Jozwik
Article
Biophysics
Zbigniew Tyfa, Paulina Jozwik, Damian Obidowski, Piotr Reorowicz, Daniel Jodko, Karolina Kapka, Ryszard Makosiej, Elzbieta Czkwianianc, Krzysztof Jozwik
ACTA OF BIOENGINEERING AND BIOMECHANICS
(2020)
Article
Biophysics
Nathan D. Camarillo, Rafael Jimenez-Silva, Frances T. Sheehan
Summary: This article discusses the statistical dependence between multiple measurements from the same participant and provides recommendations for using these measurements when they are not independent.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
J. Huet, A. -S. Boureau, A. Sarcher, C. Cornu, A. Nordez
Summary: Standard compression in freehand 3D ultrasound induces a bias in volume calculations, but minimal compression and gel pad methods have similar results. With a trained examiner and precautions, the bias can be minimized and become acceptable in clinical applications.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
C. Lariviere, A. H. Eskandari, H. Mecheri, F. Ghezelbash, D. Gagnon, A. Shirazi-Adl
Summary: Recent developments in musculoskeletal modeling have focused on model customization. Personalization of the spine profile may affect estimates of spinal loading and stability. This study investigates the biomechanical consequences of changes in the spinal profile and finds that personalizing the spine profile has medium to large effects on trunk muscle forces and negligible to small effects on spinal loading and stability.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Luke T. Mattar, Arash B. Mahboobin, Adam J. Popchak, William J. Anderst, Volker Musahl, James J. Irrgang, Richard E. Debski
Summary: Exercise therapy fails in about 25.0% of cases for individuals with rotator cuff tears, and one reason for this failure may be the inability to strengthen and balance the muscle forces that keep the humeral head in the correct position. This study developed computational musculoskeletal models to compare the net muscle force before and after exercise therapy between successfully and unsuccessfully treated patients. The study found that unsuccessfully treated patients had less inferiorly oriented net muscle forces, which may increase the risk of impingement.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Natsuki Sado, Takeshi Edagawa, Toshihide Fujimori, Shogo Hashimoto, Yoshikazu Okamoto, Takahito Nakajima
Summary: The existing methods for predicting hip and lumbosacral joint centres in Japanese adults are biased and differ between sexes. We propose new regression equations that consider soft-tissue thickness, sex differences, and a height-directional measure, and validate them using leave-one-out cross-validation.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Peimin Yu, Xuanzhen Cen, Qichang Mei, Alan Wang, Yaodong Gu, Justin Fernandez
Summary: This study aimed to explore the intra-foot biomechanical differences among individuals with chronic ankle instability (CAI), copers, and healthy individuals during dynamic tasks. The study found that copers and CAI individuals had smaller dorsiflexion angles and copers presented a more eversion position compared to healthy participants. Copers also had greater dorsiflexion angles in the metatarsophalangeal joint and more inversion moments in the subtalar joint during certain tasks. These findings can help in designing interventions to restore ankle joint functions in CAI individuals.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Jon Skovgaard Jensen, Anders Holsgaard-Larsen, Anders Stengaard Sorensen, Per Aagaard, Jens Bojsen-Moller
Summary: This study investigates the biomechanical effects of robot-assisted body weight unloading (BWU) on gait patterns in healthy young adults. The results show that dynamic robot-assisted BWU enables reduced kinetic requirements without distorting biomechanically normal gait patterns during overground walking.
JOURNAL OF BIOMECHANICS
(2024)
