bluuebunny/crossref_metadata_2025_split huggingface dataset:
Homogenization of microstructures in dynamics using periodic boundary conditions
Authors: Stadler Michael , Schanz Martin 
Published: March 2010

AbstractA homogenization method is used to calculate effective material properties of periodic microstructures subjected to small, time‐harmonic strain fields. The method is based on the equivalence of averaged micro‐field quantities in dispersive heterogeneous media and those in effective homogeneous media with frequency dependent elastic constants. Solutions to the elastodynamic boundary value problem (BVP) are obtained from a boundary element method where periodic boundary conditions on the unit‐cell are incorporated using Lagrangian multipliers. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scaling laws for turbulent boundary layer flows in favorable and adverse pressure gradient
Authors: Vigdorovich Igor 
Published: March 2010

AbstractAn analytical theory is proposed to describe incompressible plane and axisymmetric turbulent boundary layer flows in favorable and adverse pressure gradients for near‐equilibrium conditions. Scaling laws for the mean velocity, the Reynolds stress components, and the skin friction have been established. A universal friction law makes it possible to represent the skin friction distributions corresponding to different Reynolds numbers and pressure gradients in terms of a function of one variable. The theory is based on general physical assumptions and does not involve any special hypotheses on the nature of the turbulent motion. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Towards large eddy simulation on moving grids
Authors: Löbig Stefan , Dörnbrack Andreas , Fröhlich Jochen , Hertel Claudia , Kühnlein Christian , Lang Jens 
Published: March 2010

AbstractWhen turbulent flows are modelled by means of Large Eddy Simulation (LES), the characteristic length scale of the turbulent fluctuation needs to be resolved by the grid. In complex geometries this length scale varies substantially over the computational domain. The present paper proposes an approach to adjust the grid size in an LES adaptively such that the resolution capacity of a grid with a given number of points is used at best. This is done with so‐called r‐refinement. The paper presents the work of three groups collaborating on this issue. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Turbulent diffusion: Direct numerical simulation
Authors: Khujadze George , Oberlack Martin 
Published: March 2010

AbstractDirect numerical simulations (DNS) of a vibrating grid turbulence at two different Reynolds numbers (based on an amplitude and frequency of the grid) Re = 500, 1000 are presented. The evolution of a turbulent/non‐turbulent interface was detected and compared to the theoretical results obtained in the paper [1] using Lie group analysis of the governing equations. Good agreement was found between DNS and theory. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Turbulent Boundary Layer Under the Influence of Adverse Pressure Gradient
Authors: Drobniak S. , Drozdz A. , Elsner W. , Materny M. 
Published: March 2010

AbstractThe paper deals with the experimental analysis of turbulent boundary layer at the flat plate for large value of Reynolds number equal Reθ ≈︁ 3000. The adverse pressure gradient generated by curvature of the upper wall corresponded to the case of pressure variation in axial compressor. The fully developed structure of turbulence was achieved by proper triggering of the boundary layer. The mean and turbulent flow‐fields were investigated with the use of hot‐wire technique while mean and instantaneous pressure fields were examined with piezoelectric transducers. The scaling and turbulence structure of fully developed turbulent boundary layer under the influence of adverse pressure gradient revealed the more pronounced contribution of outer region to the downstream development of turbulent boundary layer. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Unstable Thermocapillary Flow at a Gas‐Liquid Phase Boundary
Authors: Schade Klaus‐Peter , Wozniak Günter , Rubes Daniel 
Published: March 2010

AbstractWe present results of thermocapillary experiments in the vicinity of a bubble under a heated wall. Thermocapillary convection is a flow along the interface of two fluids, which is caused by local gradients of the surface tensions σ.The aim of the present work is to study this flow phenomenon at higher Marangoni‐numbers Mg. At sufficiently high values of Mg the flow exhibits oscillatory fluid motion and eventually becomes turbulent. For the detection of the flow velocity and temperature field, we applied a PIV method and a modified differential interferometer. In order to separate buoyancy effects from thermocapillary convection, we chose an experimental setup, where a bubble is positioned in a liquid matrix under a heated wall.We could observe various regimes of Marangoni flow, from steady flow over regular oscillating up to highly irregular oscillating flows at Mg up to 63,000. However, we also found unexpected stable flow regions and additional evaporation processes. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Subgrid Scale Modeling of Turbulent Channel Flow with Adverse Pressure Gradient
Authors: Elsner W. , Kuban Ł. , Tyliszczak A. 
Published: March 2010

AbstractThe paper presents the results of LES simulation of turbulent channel flow with one curved wall, in which way the pressure gradient was imposed. The influence of grid density as well as subgrid scale models on the solution has been analysed. For the last purpose two models have been considered i.e. Smagorinsky and WALE. For the simulation the in‐house code SAILOR_WALL, which relies on the projection method for the pressure‐velocity coupling was used. The results were compared to the Direct Numerical Simulations (DNS) of Marquillie et al. [4]. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of bifurcating solutions of the problem about capillary‐gravity surface waves in spatial layer of floating fluid
Authors: Andronov Artyom N. , Kim‐Tyan Luiza R. , Loginov Boris V. 
Published: March 2010

AbstractIn prolongation of our previous investigations on capillary‐gravity surface waves in spatial fluid layers the stability of the bifurcating families of solutions in the horizontal layers of the floating (and without flotation) incompressible heavy capillary fluid is considered. The assumption about layer depth simplifies the proof of the existence of bifurcating solutions at the high dimensions of the linearized operator degeneracy, computation of their asymptotics and as the main subject of this communication the investigation of their stability, relative to perturbations with the same symmetry as bifurcating solutions. Group analysis methods of differential equations are used. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local Interaction Theory for Laminar Transonic Flows in Slender Channels
Authors: Kluwick Alfred , Kornfeld Matthias 
Published: March 2010

AbstractTransonic flows through channels so narrow that the classical boundary layer approach fails are considered. As a consequence the properties of the inviscid core and the viscosity dominated boundary layer region can no longer be determined in subsequent steps but have to be calculated simultaneously. The resulting viscous inviscid interaction problem for weakly three dimensional laminar flows is formulated for perfect gases under the requirement that the channel is sufficiently narrow so that the flow outside the viscous wall layers becomes planar in the leading order approximation. Representative solutions for subsonic as well as for supersonic flows disturbed by three dimensional surface mounted obstacles will be presented. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vortex Interaction in a Ducted Flow
Authors: Alexandru Dumitrache , Horia Dumitrescu , Florin Frunzulica 
Published: March 2010

AbstractThe objective of this study is to describe the structure of pipe flow by considering it as a superposition of many axisymmetric vortex rings. In knowing the unsteady gross feature of pipe flow, the investigation on vortex interactions is important. As a first step to the goal, we investigate the nonlinear interaction among vortex rings whose number is three at most. The interaction among vortex rings of equal circulation is here investigated. Momentum and energy conservation of the present vortex ring system are also discussed to know a better understanding of the perturbed pipe flow. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of the flow in semicircular canals with the method of fundamental solutions
Authors: Boselli Francesco , Obrist Dominik , Kleiser Leonhard 
Published: March 2010

AbstractWe present a numerical model for the simulation of the flow in semicircular canals (SCCs). The governing equations for the flow are solved with the method of fundamental solutions (MFS), a mesh free method for boundary value problems. We describe the flow field in a SCC with utricle, and we find a vortex that had not yet been reported in literature. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Experimental Investigation of thermal convection in an inclined narrow gap II
Authors: Rubes Daniel , Heiland Hans Georg , Wozniak Günter 
Published: March 2010

AbstractIn the past decade the development in micro technology has experienced great progress, what made the knowledge of the flow behavior in small cavities fundamentally interesting. Our experimental contribution describes the measured temperature and velocity fields in a fluid containing inclined cavity with the dimensions 17 × 6 × 24 mm3 (w × d × h). Using PIV/T, we can determine the velocity and temperature distribution in the cavity simultaneously. The chamber is illuminated with a white light sheet of 1 mm. A 20% glycerin‐water mixture is examined. The lower side is heated to 46.2°C, while the upper side has a constant temperature of 26°C. In this work we present the measured velocity and temperature fields of the fluid at different angles of the cavity orientation with respect to the direction of gravity in the stationary state. This is a continuation of last years presentation [1] in the sense that the temperature difference has been substantially increased. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Obtaining of noise map of great city of Cluj‐Napoca. Step by step.
Authors: Solea Geamilia , Arghir Mariana 
Published: March 2010

AbstractThe traffic of autovehicles in pilot zone of great city of Cluj‐Napoca is presented in the work. There are established the noise measuring locations for the fixed station and successive positions of the mobile station in pilot zone. Noise pollution measurements are done on the mentioned locations. The “Sound plan” programme pack is used to fulfill the sound map of the great city of Cluj‐Napoca; its graphic representation is compared to the real measurement results. Present paper represents a part of research activity of T.U.C.N. researchers in studying for fulfilling of E.U. tasks of environment protection. This research is made for the application of the EU legislation on the Romanian cities. First we worked in the great city of Cluj‐Napoca, but the extensions will be to all the urban agglomerations having greater than 100000 people. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of Piezoelectric Induced Lamb Waves in Plates
Authors: Vivar‐Perez Juan Miguel , Willberg Christian , Gabbert Ulrich 
Published: March 2010

AbstractIn the paper, piezoelectric induced Lamb wave propagation on homogeneous plates is studied by applying different approaches. Assuming the presence of piezoelectric actuators and sensors the transient wave analysis is made using the classical formulation of the finite element method (FEM) and the novel approach of spectral finite element method (SE). Pure mode excitation and mode conversion are numerically simulated for the fundamental modes S0 and A0. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of fluid transients, for nonlinear fluids, with a lumped parameter model
Authors: Haas Rainer , Manhartsgruber Bernhard 
Published: March 2010

AbstractThis paper deals with the modeling of transients in low pressure transmission lines. Modeling of low pressure lines becomes more and more important for increasing efficiency of fast switching applications and performance of pumps e.g. common rail diesel injection systems and suction pipes of pumps. One simulation method is the lumped parameter model. For example a straight pipe can be modeled as a cascade of inertia, friction and compressibility blocks. In this paper, the idea of cascades is adopted for transient simulation of nonlinear fluids. The model includes a nonlinear fluid law of an oil‐air mixture and the balance equations i.e. the compressibility and the inertia of the fluid. Friction is modeled by the frequency dependent friction model of Kagawa et.al. Comparison of simulation results with measurements from a test rig shows good correlation. Finally the scope of this simulation model is discussed and compared with measurements. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear Elastic Wave Propagation in Unsaturated, Unconsolidated Soils
Authors: Albers Bettina 
Published: March 2010

AbstractBy means of a macroscopic linear model for a poroelastic medium with three deformable components the acoustic behavior of four unconsolidated soil types, filled by water and air, is studied. Necessary material parameters are mainly gathered from the German standard DIN 4220. It provides some useful parameters, as for example, van Genuchten parameters, for thirty‐one different soil types including sands, silts and clays. There appear four body waves: three longitudinal waves and one shear wave. The slowest compressional wave does only exist if at least two pore fluids appear and is driven by the capillary pressure between the pore fluids. The wave analysis yields the dependence of velocities and attenuations of these waves on the saturation and on the frequency. This is compared to the so far most frequently studied case of partially saturated sandstones. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lp – Lq time decay estimate to the solution of the Cauchy problem for the system of equations describing nonlocal model of the thermoviscoelastic body
Authors: Gawinecki Jerzy , Lazuka Jaroslaw , Rafa Jozef 
Published: March 2010

AbstractThe aim of this paper is to present a new system of equations describing nonlocal model of thermoviscoelastic theory. We used the Papkin and Gurtin approach based on the constitutive relations for stress tensor σ(x), internal energy e(x) and heat flux q(x), with integral terms. Using the modified Cagniard‐de Hoop's method we constructed the matrix of fundamental solutions for this system of equations in three‐dimensional space. Basing on this matrix we represent in the explicit formula the solution of the Cauchy problem to this system of equations. Next, applying the method of Sobolev spaces, we proved the Lp–Lq time decay estimate to the solution of the Cauchy problem. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of parametric modulation on the onset of thermomagnetic convection
Authors: Engler H. , Odenbach S. 
Published: March 2010

AbstractMagnetic fluids – so called ferrofluids – are suspensions of nano‐scaled particles in an appropriate carrier liquid. The flow properties of these fluids can be influenced by applying an external magnetic field. It is possible to introduce a magnetic force in a horizontal ferrofluid layer which is able to drive a convective flow. The magnetic force arises in the presence of an external magnetic field if a temperature gradient exists in the fluid gap. The behaviour of the onset of convection depends on the strength of the external magnetic field and on the temperature gradient. In this paper the onset of convection under the influence of time‐modulated magnetic field has been investigated. The experimental results presented here show a shift in the onset of convection depending on the frequency of the external magnetic field. This behaviour confirms in principle the theoretical predictions which are also presented here. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cross‐calibration of X‐ray µCT and MRX for tissue analysis
Authors: Rahn H. , Eberbeck D. , Richter H. , Gomez‐Morilla I. , Trahms L. , Odenbach S. 
Published: March 2010

AbstractFerrofluids are being considered as an aid for local cancer treatments, such as Magnetic Drug Targeting (MDT) and Magnetic Hyperthermia (MHT). Both methods make use of the strong influence of a magnetic field on the nanoparticles, with the aim of treating the cancer locally while reducing, or even eliminating, the side effects that usually occur during conventional cancer treatments. Microcomputed tomography analysis has been performed on tumour tissue after MDT and MHT in order to examine the distribution of the magnetic nanoparticles within the tissue. The majority of the measurements has been performed in a laboratory based on a polychromatic X‐ray source. The strong energy dependence of the attenuation coefficient and the occurrence of the so called beam hardening artefacts make the quantitative evaluation of data acquired with polychromatic tomography equipment very difficult. In this paper we present a cross‐calibration method for magnetorelaxometry and polychromatic X‐ray tomography for biological tissue samples enriched with magnetic nanoparticles. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Green functions for boundary value problems about divergence of elongated plate
Authors: Badokina Tatiana E. , Loginov Boris V. , V. Makeeva Olga 
Published: March 2010

AbstractBucking of a thin flexible elongated plate in supersonic gas flow along Ox‐axis, compressed or extended by boundary stresses at the edges x = 0 and x = 1 is governed by a boundary value problem for nonlinear ordinary integro‐differential equation with two bifurcation parameters: external stress and Mach number. On two examples of boundary conditions Bw″(0) = 0, w‴(0) = 0, w(1) = 0, w′(1) = 0 and B′ w(0) = 0, w′(0) = 0, w″(1) = 0, w‴(1) = 0. Green functions for the linearized problems are constructed. Arising technical difficulties are overcoming with the aid of the bifurcation curves representation through the roots of relevant characteristic equations. In the known literature [1] marked, that Green functions for aeroelasticity problems were not constructed. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimization the shape of finite element in shot peening process
Authors: Szyc Marcin , Kukielka Leon , Bartosik Przemyslaw 
Published: March 2010

AbstractThis paper contains modelling and numerical simulations of shot peening process. The application in Ansys/LS – Dyna programme were elaborated. The phenomena of shot peening process on a typical incremental step were described using a step‐by‐step incremental procedure, with an updated Lagrangian formulation.Finite elements methods (FEM) and the dynamic explicit method (DEM) were used to obtain the solution. The main purpose of this article is to determinate optimal model of shot peening process (convergence resulting for minimal number of finite elements and their optimal shapes). Examples of calculations were presented. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation and Analysis of Thermal Fatigue Based on Imperfection Model of Brake Discs
Authors: Zhang Lele , Yang Qiang , Weichert D. , Tan Nanlin 
Published: March 2010

AbstractA non‐linear FEM model of brake discs of high‐speed trains with thermal‐mechanical coupling has been established in ANSYS. The simulation and analysis of 3‐D transient temperature field and stress field of brake discs have been carried out for the braking process. According to typical imperfections of brake discs, some imperfection models of brake discs have been developed and the thermal stresses of different models are obtained through simulation and analysis. By comparing results of different models, the influence of imperfection parameters, including the position, depth and size, is resulted for the thermal resistance of brake discs. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On stability of asymptotic energy for a functional of Ginzburg‐Landau type with ε‐dependent weakly‐star convergent 1‐Lipschitz penalizing term
Authors: Raguž Andrija 
Published: March 2010

AbstractWe apply the approach developed in the paper G. Alberti, S. Müller: A new approach to variational problems with multiple scales, Comm. Pure Appl. Math. 54, 761‐825 (2001) to calculate rescaled asymptotic energy associated to certain Ginzburg‐Landau functional in one dimension. We generalize results from the paper A. Raguž: Relaxation of Ginzburg‐Landau functional with 1‐Lipschitz penalizing term in one dimension by Young measures on micropatterns, Asymptotic Anal. 41(3,4), 331‐361 (2005), where original functional was penalized by 1‐Lipschitz function g. In this note we consider the case when such penalizing functions depend on small parameter ε as their derivatives oscillate with period equal to ε to the power of γ for some γ > 0. We show that there are three distinctive cases of γ which lead to different asymptotic energy. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The sensitivity analysis of the drawpiece response on the material model parameters
Authors: Kaldunski Pawel , Kukielka Leon 
Published: March 2010

AbstractOn this paper the numerical analysis of the drawing process with use the Finite Element Method is presented. The sensitivity of stresses field on the edge and the round edge of drawpiece on the tangent modulus and yield stress is defined. The analysis with the explicit method in the ANSYS LS‐Dyna system is passed. The Die and the stamp as not deformable bodies are accepted and with the shell finite elements are discretized. The drawpiece with the solid finite elements are discretized. Sample results of computer simulations are presented. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Reissner‐Mindlin plate is the Γ‐limit of Cosserat elasticity
Authors: Neff Patrizio , Hong Kwon‐Il , Jeong Jena 
Published: March 2010

AbstractThe linear Reissner‐Mindlin membrane‐bending plate model is the rigorous Γ‐limit for zero thickness of a linear isotropic Cosserat bulk model with symmetric curvature. For this result we use the natural nonlinear scaling for the displacements u and the linear scaling for the infinitesimal microrotations Ā ∈ so(3) affecting the in‐plane drill rotations. No boundary conditions on the microrotations are prescribed. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fractal analysis of thermally sprayed coatings
Authors: Łabacz‐Kęcik Anna , Hejwowski Tadeusz , Litak Grzegorz 
Published: March 2010

AbstractFunctional performance of thermally sprayed coatings depends to a large degree on their surface topography. Surface topography of coatings was studied by analyzing numerically data sets aquired by contact profilometry. The effect of spraying method and powder composition was explored for a range of coatings. The effect of coating composition was studied for cermet coatings flame sprayed with mixtures of Ni‐5%Al with ZrO2‐30%CaO. To characterize the coating surface topography, multifractal analysis was performed. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)