نتایج جستجو برای: flow stress

تعداد نتایج: 900063  

2016
Sven De Schampheleire Kathleen De Kerpel Bernd Ameel Peter De Jaeger Ozer Bagci Michel De Paepe

It is long known that for high-velocity fluid flow in porous media, the relation between the pressure drop and the superficial velocity is not linear. Indeed, the classical Darcy law for shear stress dominated flow needs to be extended with a quadratic term, resulting in the empirical Darcy-Forchheimer model. Another approach is to simulate the foam numerically through the volume averaging tech...

Journal: :Journal of biomechanical engineering 2009
Dalin Tang Chun Yang Shunichi Kobayashi Jie Zheng Pamela K Woodard Zhongzhao Teng Kristen Billiar Richard Bach David N Ku

Heart attack and stroke are often caused by atherosclerotic plaque rupture, which happens without warning most of the time. Magnetic resonance imaging (MRI)-based atherosclerotic plaque models with fluid-structure interactions (FSIs) have been introduced to perform flow and stress/strain analysis and identify possible mechanical and morphological indices for accurate plaque vulnerability assess...

Turbulent flow over wall-mounted cube in a channel was investigated numerically using Large Eddy Simulation. The Selective Structure Function model was used to determine eddy viscosity that appeared in the subgrid scale stress terms in momentum equations. Studies were carried out for the flows with Reynolds number ranging from 1000 to 40000. To evaluate the computational results, data was compa...

Journal: :Stroke 2009
Jamila Ibrahim Bradford C Berk

BACKGROUND AND PURPOSE Changes in shear and medial wall stress induced by blood flow contribute to vascular remodeling, but details of these relations remain undefined. We hypothesized that remodeling has a strong genetic component and that phenotypic responses to hemodynamic stress will differ among rat strains. Here, we characterized phenotypic traits related to carotid remodeling in the 2 ra...

Journal: :Circulation research 2014
Oded N Spindel Ryan M Burke Chen Yan Bradford C Berk

RATIONALE Fluid shear stress differentially regulates endothelial cell stress fiber formation with decreased stress fibers in areas of disturbed flow compared with steady flow areas. Importantly, stress fibers are critical for several endothelial cell functions including cell shape, mechano-signal transduction, and endothelial cell-cell junction integrity. A key mediator of steady flow-induced ...

Journal: :Physical review letters 2010
Gustavo Gioia Nicholas Guttenberg Nigel Goldenfeld Pinaki Chakraborty

It has long been surmised that the mean-velocity profile (MVP) of pipe flows is closely related to the spectrum of turbulent energy. Here we perform a spectral analysis to identify the eddies that dominate the production of shear stress via momentum transfer. This analysis allows us to express the MVP as a functional of the spectrum. Each part of the MVP relates to a specific spectral range: th...

Journal: :international journal of iron & steel society of iran 2011
j. rasti a. najafizadeh m. meratian

in the hot compression test friction has a detrimental influence on the flow stress through the process and therefore, correcting the deformation curve for real behavior is very important for both researchers and engineers. in this study, a series of compression tests were simulated using abaqus software. in this study, it has been employed the taguchi method to design experiments by the factor...

Journal: :Journal of vascular surgery 2004
Eiketsu Sho Hiroshi Nanjo Mien Sho Mikio Kobayashi Masayo Komatsu Koichi Kawamura Chengpei Xu Christopher K Zarins Hirotake Masuda

We investigated the effects of sequential and prolonged exposure to high and low wall shear stress on arterial remodeling using a rabbit arteriovenous fistula (AVF) model. Blood flow was increased by approximately 17-fold to 20-fold when the AVF was open, and returned to normal when the AVF was occluded. Repeated opening and closing of the AVF resulted in sequential exposure of the artery to hi...

Journal: :BioMedical Engineering OnLine 2006
Eric J Anderson Thomas D Falls Adam M Sorkin Melissa L Knothe Tate

BACKGROUND In vitro mechanotransduction studies are designed to elucidate cell behavior in response to a well-defined mechanical signal that is imparted to cultured cells, e.g. through fluid flow. Typically, flow rates are calculated based on a parallel plate flow assumption, to achieve a targeted cellular shear stress. This study evaluates the performance of specific flow/perfusion chambers in...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم ریاضی و مهندسی کامپیوتر 1392

heuristics are often used to provide solutions for flow shop scheduling problems.the performance of a heuristic is usually judged by comparing solutions and run times on test cases.this investigation proposes an analytical alternative ,called asymptotic convergence ,which tests the convergence of the heuristic to a lower bound as problem size grows. the test is a stronger variation of worst cas...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید