Relevant bibliographies by topics / Shear-free and irrotational models

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Shear-free and irrotational models'

Author: Grafiati
Published: 4 June 2021
Last updated: 19 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Shear-free and irrotational models.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Shear-free and irrotational models"

1

Abebe, Amare, and Maye Elmardi. "Irrotational-fluid cosmologies in fourth-order gravity." International Journal of Geometric Methods in Modern Physics 12, no. 10 (October 25, 2015): 1550118. http://dx.doi.org/10.1142/s0219887815501182.

Full text
Abstract:
In this paper, we explore classes of irrotational-fluid cosmological models in the context of f(R)-gravity in an attempt to put some theoretical and mathematical restrictions on the form of the f(R) gravitational Lagrangian. In particular, we investigate the consistency of linearized dust models for shear-free cases as well as in the limiting cases when either the gravito-magnetic or gravito-elecric components of the Weyl tensor vanish. We also discuss the existence and consistency of classes of non-expanding irrotational spacetimes in f(R)-gravity.
APA, Harvard, Vancouver, ISO, and other styles
2

PATEL, L. K., and LAKSHMI S. DESAI. "PLANE SYMMETRIC VISCOUS-FLUID COSMOLOGICAL MODELS WITH HEAT FLUX." International Journal of Modern Physics D 03, no. 03 (September 1994): 639–45. http://dx.doi.org/10.1142/s0218271894000770.

Full text
Abstract:
A class of nonstatic inhomogeneous plane-symmetric solutions of Einstein field equations is obtained. The source for these solutions is a viscous fluid with heat flow. The fluid flow is irrotational and it has nonzero expansion, shear and acceleration. All these solutions have a big-bang singularity. The matter-free limit of the solutions is the well-known Kasner vacuum solution. Some physical features of the solutions are briefly discussed.
APA, Harvard, Vancouver, ISO, and other styles
3

CHIMENTO, LUIS P., and WINFRIED ZIMDAHL. "DUALITY INVARIANCE AND COSMOLOGICAL DYNAMICS." International Journal of Modern Physics D 17, no. 12 (November 2008): 2229–54. http://dx.doi.org/10.1142/s0218271808013820.

Full text
Abstract:
A duality transformation that interrelates expanding and contracting cosmological models is shown to single out a duality invariant, interacting two-component description of any irrotational, geodesic and shear-free cosmic medium with vanishing three-curvature scalar. We have applied this feature to a system of matter and radiation, to a mixture of dark matter and dark energy, to minimal and conformal scalar fields, and to an enlarged Chaplygin gas model of the cosmic substratum. We have extended the concept of duality transformations to cosmological perturbations and demonstrated the invariance of adiabatic pressure perturbations under these transformations.
APA, Harvard, Vancouver, ISO, and other styles
4

Chase, D. M. "Fluctuations in wall-shear stress and pressure at low streamwise wavenumbers in turbulent boundary-layer flow." Journal of Fluid Mechanics 225 (April 1991): 545–55. http://dx.doi.org/10.1017/s0022112091002161.

Full text
Abstract:
Turbulent boundary-layer fluctuations in the incompressive domain are expressed in terms of fluctuating velocity-product 'sources’ in order to elucidate relative characteristics of fluctuating wall-shear stress and pressure in the subconvective range of streamwise wavenumbers. Appropriate viscous wall conditions are applied, and results are obtained to lowest order in this Strouhal-scaled wavenumber which serves as the expansion parameter. The spectral amplitudes of pressure and of the shear stress component directed along the wavevector both contain additive terms proportional to source integrals with exponential wall-distance weighting characteristic respectively of the irrotational and the rotational fields. At low wavenumbers, barring unexpected relative smallness of the pertinent boundary-layer source term, the rotational terms become dominant. There the wall pressure and shear-stress component have spectra that approach the same non-vanishing, wavevector-white but generally viscous-scale-dependent level and are totally coherent with phase difference ½π. The other, irrotational contributions to the shear-stress and pressure amplitudes likewise bear a simple and previously known, generally wavevector– and frequency-dependent, ratio to one another. In an inviscid limit this contribution to the pressure amplitude reduces to the one obtained previously from inviscid treatments. A representative class of models is introduced for the source spectrum, and the resulting rotational contribution to the spectral density of wall pressure and K-aligned shear stress at low (but incompressive) wavenumbers is estimated. It is suggested that this contribution may predominate and account for measured low-wavenumber levels of wall pressure.
APA, Harvard, Vancouver, ISO, and other styles
5

Kojima, Yasufumi, Shota Kisaka, and Kotaro Fujisawa. "Magneto-elastic equilibrium of a neutron star crust." Monthly Notices of the Royal Astronomical Society 506, no. 3 (July 19, 2021): 3936–45. http://dx.doi.org/10.1093/mnras/stab1848.

Full text
Abstract:
ABSTRACT We examine the equilibrium of a magnetized neutron star crust. We calculate axially symmetric models in which an elastic force balances solenoidal motion driven by a Lorentz force. A large variety of equilibrium models are allowed by incorporating the elastic shear deformation; in addition, toroidal-magnetic-field-dominated models are available. These results remarkably differ from those in barotropic fluid stars. We demonstrate some models wherein the magnetic energy exceeds the elastic energy. The excess comes from the fact that a large amount of magnetic energy is associated with the irrotational part of the magnetic force, which is balanced with gravity and pressure. It is sufficient for equilibrium models that the minor solenoidal part is balanced by a weak elastic force. We find that the elasticity in the crust plays an important role on the magnetic field confinement. Further, we present the spatial distribution of the shear stress at the elastic limit, by which the crust-fracture location can be identified. The result has useful implications for realistic crust-quake models.
APA, Harvard, Vancouver, ISO, and other styles
6

Compelli, A., R. Ivanov, and M. Todorov. "Hamiltonian models for the propagation of irrotational surface gravity waves over a variable bottom." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2111 (December 11, 2017): 20170091. http://dx.doi.org/10.1098/rsta.2017.0091.

Full text
Abstract:
A single incompressible, inviscid, irrotational fluid medium bounded by a free surface and varying bottom is considered. The Hamiltonian of the system is expressed in terms of the so-called Dirichlet–Neumann operators. The equations for the surface waves are presented in Hamiltonian form. Specific scaling of the variables is selected which leads to approximations of Boussinesq and Korteweg–de Vries (KdV) types, taking into account the effect of the slowly varying bottom. The arising KdV equation with variable coefficients is studied numerically when the initial condition is in the form of the one-soliton solution for the initial depth. This article is part of the theme issue ‘Nonlinear water waves’.
APA, Harvard, Vancouver, ISO, and other styles
7

Ilin, Konstantin. "Shallow-water models for a vibrating fluid." Journal of Fluid Mechanics 833 (November 2, 2017): 1–28. http://dx.doi.org/10.1017/jfm.2017.687.

Full text
Abstract:
We consider a layer of an inviscid fluid with a free surface which is subject to vertical high-frequency vibrations. We derive three asymptotic systems of equations that describe slowly evolving (in comparison with the vibration frequency) free-surface waves. The first set of equations is obtained without assuming that the waves are long. These equations are as difficult to solve as the exact equations for irrotational water waves in a non-vibrating fluid. The other two models describe long waves. These models are obtained under two different assumptions about the amplitude of the vibration. Surprisingly, the governing equations have exactly the same form in both cases (up to the interpretation of some constants). These equations reduce to the standard dispersionless shallow-water equations if the vibration is absent, and the vibration manifests itself via an additional term which makes the equations dispersive and, for small-amplitude waves, is similar to the term that would appear if surface tension were taken into account. We show that our dispersive shallow-water equations have both solitary and periodic travelling wave solutions and discuss an analogy between these solutions and travelling capillary–gravity waves in a non-vibrating fluid.
APA, Harvard, Vancouver, ISO, and other styles
8

LABERTEAUX, K. R., and S. L. CECCIO. "Partial cavity flows. Part 1. Cavities forming on models without spanwise variation." Journal of Fluid Mechanics 431 (March 25, 2001): 1–41. http://dx.doi.org/10.1017/s0022112000002925.

Full text
Abstract:
Partial cavities that formed on the vertices of wedges and on the leading edge of stationary hydrofoils were examined experimentally. The geometry of these test objects did not vary in the spanwise direction (i.e. two-dimensional). Open partial cavities formed on a series of two-dimensional wedges and on a plano-convex hydrofoil. These cavities terminated near the point of maximum cavity thickness, and small vapour-filled vortices were shed in the turbulent cavity wake. The turbulent flow in the wake of the open cavity was similar to the turbulent shear flow downstream of a rearward-facing step. Re-entrant flow was not observed in the cavity closure of open cavities, although recirculating flow associated with a region of flow separation was detected for some cases. Predictions of a two-dimensional free-streamline model of the cavitating wedge flows were compared to the experimentally observed cavities. The model predicted the profile of the open cavity only to the point of maximum cavity thickness. Examination of the flow field near the closure of the open cavities revealed adverse pressure gradients near the cavity closure. The pressure gradients around the open cavities were sufficient to cause large-scale condensation of the cavity. Unsteady re-entrant partial cavities formed on a two-dimensional NACA0009 hydrofoil. The interface of the unsteady closed cavities smoothly curved to form a re-entrant jet at the cavity terminus, and the re-entrant flow was directed upstream. The re-entrant flow impinged on the cavity interface and led to the periodic production of cloud cavitation. These cavities exhibited a laminar flow reattachment. The flow around the closed cavity was largely irrotational, while vorticity was created when the cloud cavitation collapsed downstream of the cavity. Examination of the flow field near closure of these cavities also revealed adverse pressure gradients near the partial cavity closure, but the rise in pressure did not lead to the premature condensation of the cavity.
APA, Harvard, Vancouver, ISO, and other styles
9

Sami, Heba, and Amare Abebe. "Perturbations of quasi-Newtonian universes in scalar–tensor gravity." International Journal of Geometric Methods in Modern Physics 18, no. 10 (June 29, 2021): 2150158. http://dx.doi.org/10.1142/s0219887821501589.

Full text
Abstract:
In this contribution, we consider the well-known equivalence between [Formula: see text] gravity and Brans–Dicke-type scalar–tensor theories to study the evolution of scalar cosmological perturbations for a class of shear-free cosmological dust models with irrotational fluid flows. We use the [Formula: see text] covariant formalism to present the covariant linearized evolution and constraint equations. We then derive the integrability conditions describing a consistent evolution of the linearized field equations of quasi-Newtonian universes in the modified (scalar–tensor) theory of gravity. Finally, we derive the evolution equations for the density and velocity perturbations of the quasi-Newtonian universe. We apply the harmonic decomposition and explore the behavior of the matter density contrast by considering [Formula: see text] toy models. The growth of the matter density contrast for both short- and long-wavelength modes has been examined by applying certain assumptions of the initial conditions. We then apply the so-called quasi-static approximation to obtain exact solutions on small scales, but the results show that this approximation is not applicable here. Moreover, any small deviation from general relativity and any small change in the initial conditions of the perturbations causes huge orders-of-magnitude deviations from limiting general relativistic results, potentially putting constraints on the modified theory in the quasi-Newtonian cosmologies treatment. Our current work differs from other works in the literature, in that it is the first such work to show quasi-Newtonian cosmologies are unstable to linearized perturbations in modified gravity.
APA, Harvard, Vancouver, ISO, and other styles
10

COLEMAN, G. N., D. FEDOROV, P. R. SPALART, and J. KIM. "A numerical study of laterally strained wall-bounded turbulence." Journal of Fluid Mechanics 639 (August 28, 2009): 443–78. http://dx.doi.org/10.1017/s0022112009991042.

Full text
Abstract:
Direct numerical simulation (DNS) is used to study the effects of mean lateral divergence and convergence on wall-bounded turbulence, by applying uniform irrotational temporal deformations to a plane-channel domain. This extends a series of studies of similar deformations. Fast and slow straining fields are considered, leading to a matrix of four cases, all corresponding to zero-pressure-gradient (ZPG) flows along the centreplane in ducts with constant rectangular cross-sectional area but varying aspect ratio. The results are used to address basic physical and modelling questions, and create a database that allows detailed yet straightforward testing of turbulence models. Initial tests of three representative one-point models reveal meaningful differences. The extra-strain effects introduced by the matrix of fast and slow divergence and convergence are documented, separating the direct effects of the strain from the indirect ones that alter the shear rate and change the distance from the wall. Some findings are predictable, and none contradict experimental findings. Others require more thought, notably an asymmetry between the effect of convergence and divergence on the peak turbulence kinetic energy.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Shear-free and irrotational models"

1

Holgersson, David. "Lanczos potentialer i kosmologiska rumtider." Thesis, Linköping University, Department of Mathematics, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2582.

Full text
Abstract:

We derive the equation linking the Weyl tensor with its Lanczos potential, called the Weyl-Lanczos equation, in 1+3 covariant formalism for perfect fluid Bianchi type I spacetime and find an explicit expression for a Lanczos potential of the Weyl tensor in these spacetimes. To achieve this, we first need to derive the covariant decomposition of the Lanczos potential in this formalism. We also study an example by Novello and Velloso and derive their Lanczos potential in shear-free, irrotational perfect fluid spacetimes from a particular ansatz in 1+3 covariant formalism. The existence of the Lanczos potential is in some ways analogous to the vector potential in electromagnetic theory. Therefore, we also derive the electromagnetic potential equation in 1+3 covariant formalism for a general spacetime. We give a short description of the necessary tools for these calculations and the cosmological formalism we are using.

APA, Harvard, Vancouver, ISO, and other styles
2

Hipp, Hans Christoph 1959. "Numerical investigation of mode interaction in free shear layers." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276871.

Full text
Abstract:
Numerical simulations of incompressible, two-dimensional, monochromatically and bichromatically forced laminar free shear layers are performed on the basis of a vorticity-velocity formulation of the complete Navier-Stokes equations employing central finite differences. Spatially periodic shear layers developing in time (temporal model) are compared with shear layers developing in the stream-wise direction (spatial model). The regimes of linear growth and saturation of the fundamental are quantitatively scrutinized, the saturation of the subharmonic and vortex merging are investigated, and the effects of a forcing phase-shift between fundamental and subharmonic. For the spatial model the appearance of an unforced subharmonic was also examined. It was found that contrary to temporal shear layers a significant control of vortex merging by means of a forcing phase-shift and vortex shredding are not possible in spatial shear layers due to strong dispersion.
APA, Harvard, Vancouver, ISO, and other styles
3

PRUETT, CHARLES DAVID. "NUMERICAL SIMULATION OF NONLINEAR WAVES IN FREE SHEAR LAYERS (MIXING, COMPUTATIONAL, FLUID DYNAMICS, HYDRODYNAMIC STABILITY, SPATIAL, FLUID FLOW MODEL)." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183869.

Full text
Abstract:
A numerical model has been developed which simulates the three-dimensional stability and transition of a periodically forced free shear layer in an incompressible fluid. Unlike previous simulations of temporally evolving shear layers, the current simulations examine spatial stability. The spatial model accommodates features of free shear flow, observed in experiments, which in the temporal model are precluded by the assumption of streamwise periodicity; e.g., divergence of the mean flow and wave dispersion. The Navier-Stokes equations in vorticity-velocity form are integrated using a combination of numerical methods tailored to the physical problem. A spectral method is adopted in the spanwise dimension in which the flow variables, assumed to be periodic, are approximated by finite Fourier series. In complex Fourier space, the governing equations are spatially two-dimensional. Standard central finite differences are exploited in the remaining two spatial dimensions. For computational efficiency, time evolution is accomplished by a combination of implicit and explicit methods. Linear diffusion terms are advanced by an Alternating Direction Implicit/Crank-Nicolson scheme whereas the Adams-Bashforth method is applied to convection terms. Nonlinear terms are evaluated at each new time level by the pseudospectral (collocation) method. Solutions to the velocity equations, which are elliptic, are obtained iteratively by approximate factorization. The spatial model requires that inflow-outflow boundary conditions be prescribed. Inflow conditions are derived from a similarity solution for the mean inflow profile onto which periodic forcing is superimposed. Forcing functions are derived from inviscid linear stability theory. A numerical test case is selected which closely parallels a well-known physical experiment. Many of the aspects of forced shear layer behavior observed in the physical experiment are captured by the spatial simulation. These include initial linear growth of the fundamental, vorticity roll-up, fundamental saturation, eventual domination of the subharmonic, vortex pairing, emergence of streamwise vorticity, and temporary stabilization of the secondary instability. Moreover, the spatial simulation predicts the experimentally observed superlinear growth of harmonics at rates 1.5 times that of the fundamental. Superlinear growth rates suggest nonlinear resonances between fundamental and harmonic modes which are not captured by temporal simulations.
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Shear-free and irrotational models"

1

Tzuoo, K. L. Zonal models of turbulence and their application to free shear flows. Stanford, Calif: Thermosciences Division, Dept. of Mechanical Engineering, Stanford University, 1986.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kamada, Ray. Amending the w* velocity scale for surface layer, entrainment zone, and baroclinic shear in mixed forced/free turbulent convection. Monterey, Calif: Naval Postgraduate School, 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Chiang, Chu, Lumley John L. 1930-, and Lewis Research Center. Institute for Computational Mechanics in Propulsion., eds. Modeling of wall-bounded complex flows and free shear flows. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, Institute for Computational Mechanics in Propulsion, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Jiang, Zhu, Lumley John L. 1930-, and Lewis Research Center. Institute for Computational Mechanics in Propulsion., eds. Modeling of wall-bounded complex flows and free shear flows. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, Institute for Computational Mechanics in Propulsion, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Modeling of wall-bounded complex flows and free shear flows. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, Institute for Computational Mechanics in Propulsion, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Chiang, Chu, Lumley John L. 1930-, and Lewis Research Center. Institute for Computational Mechanics in Propulsion., eds. Modeling of wall-bounded complex flows and free shear flows. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, Institute for Computational Mechanics in Propulsion, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Hypersonic turbulent boundary-layer and free shear database. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Wang, Shen. Numerical simulation of coupling effects in multiphase free shear flows. 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

N, Tiwari S., and United States. National Aeronautics and Space Administration., eds. Investigation of high-speed free shear flows using improved pressure-strain correlated Reynolds stress turbulence models. Norfolk, Va: Old Dominion University Research Foundation, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

N, Tiwari, and United States. National Aeronautics and Space Administration., eds. Investigation of high-speed free shear flows using improved pressure-strain correlated Reynolds stress turbulence models. Norfolk, Va: Old Dominion University Research Foundation, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Shear-free and irrotational models"

1

Landa, Tim, René-Daniel Cécora, and Rolf Radespiel. "Application of Reynolds-Stress-Models on Free Shear Layers." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 189–206. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-72020-3_12.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Dreßler, B. "Application of Two-Parameter Turbulence Models to the Prediction of Two-Dimensional Free Turbulent Shear Flows." In Notes on Numerical Fluid Mechanics (NNFM), 111–18. Wiesbaden: Vieweg+Teubner Verlag, 1997. http://dx.doi.org/10.1007/978-3-322-86573-1_14.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Shear-free and irrotational models"

1

Tselepidakis, Dimitri P., and Sung-Eun Kim. "Modeling and Prediction of the Laminar Leading-Edge Separation and Transition in a Blade-Cascade Flow." In ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/96-gt-411.

Full text
Abstract:
This paper presents the computation of the flow around a controlled diffusion compressor cascade. Features associated with by-pass transition close to the leading edge — including laminar leading-edge separation — contribute significantly to the evolution of the boundary layer on the blade surface. Previous studies have demonstrated that conventional k-ε models, based on linear or non-linear Boussinesq stress-strain relations, are able to capture by-pass transition in simple shear, but are unable to resolve transitional features in complex strain, like the leading-edge separation bubble, which is of considerable influence to the suction-side flow at high inlet angle. Here, the k-ω turbulence model has been implemented in a nonstaggered, finite-volume based segregated Reynolds-Averaged Navier-Stokes solver. We demonstrate that this model, if properly sensitized to the generation of turbulence by irrotational strains, is capable of capturing the laminar leading-edge separation bubble. The real flow around the leading edge is laminar and the transition is only provoked on the reattachment region. Additional investigation of transition in a flat-plate boundary layer development has also produced reasonably promising results.
APA, Harvard, Vancouver, ISO, and other styles
2

Pakozdi, Csaba, Arun Kamath, Weizhi Wang, and Hans Bihs. "Representation of Breaking Wave Kinematics in the Fully Nonlinear Potential Flow Model REEF3D::FNPF." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18160.

Full text
Abstract:
Abstract Robust simulations over three-hours are essential to represent a stationary sea state and derive wave statistics and structural response of marine structures in a reliable manner. This means that the numerical model used for the simulation of the sea state should be computationally efficient, stable and accurate. The fully nonlinear potential flow (FNPF) model solving the Laplace equations is found to be a good tool for this application. The drawback of using the FNPF model is the representation of wave breaking. Due to the assumptions of irrotational flow, it is not possible to represent an overturning free surface which occurs as a result of wave breaking. Therefore, there is a need to investigate a method to represent the effect of wave breaking in an efficient yet accurate manner. In this paper, the open-source model REEF3D::FNPF is used. The model demonstrates good robust performance and stability even in the presence of breaking waves in the domain. However, it is noticed that the free surface in the aftermath of wave breaking is slightly over predicted. This results in waves in the post-breaking region that are higher and steeper than expected after wave breaking. This difference can be avoided by incorporating techniques to correctly reduce the wave energy in the post-breaking region by the means of a reasonable damping mechanism. Breaking waves generated in the facility at SINTEF Ocean/NTNU are simulated in REEF3D::FNPF. Earlier presented results of Star-CCM+ [1] are used in the comparison. The free surface measured at several different locations in the Small towing tank are compared to the numerical results. As published earlier, the CFD model represents the model test data well. Further, the effect of wave breaking in the numerical models is investigated by comparing the numerical results from both models. The difference in the free surface representation is used to analyze the damping factor required in the FNPF model, compared to the wave kinematics represented in the CFD model. Further, REEF3D::FNPF is used to carry out three-hour long simulations with the JONSWAP spectrum in intermediate water depth conditions in order to identify the influence of the breaking model parameters on the statistical properties of the generated waves and compared against model test data.
APA, Harvard, Vancouver, ISO, and other styles
3

Wei, Mingjun, and Clarence Rowley. "Low-Dimensional Models of a Temporally Evolving Free Shear Layer." In 36th AIAA Fluid Dynamics Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2006. http://dx.doi.org/10.2514/6.2006-3228.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Balakrishnan, L., S. Tiwari, K. Abdol-Hamid, L. Balakrishnan, S. Tiwari, and K. Abdol-Hamid. "Prediction of high-speed free shear flows using higher-order turbulence models." In 35th Aerospace Sciences Meeting and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1997. http://dx.doi.org/10.2514/6.1997-762.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Wu, Chin H., and Chih-Chieh Young. "Efficient Non-Hydrostatic Modeling for Free Surface Waves in Deep and Shallow Water." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79894.

Full text
Abstract:
A novel approach that introduces the Boussinesq-type like equations into an implicit non-hydrostatic model, free of irrotational flow assumption, is presented. The basic concept is to obtain an analytical-based form of pressure distribution at the top layer by matching the reference velocity under a virtual grid system with the one under a non-hydrostatic model grid system. Locations of the references velocities are tuned to optimize the linear wave dispersion property in the model. Efficiency of this non-hydrostatic model with Boussinesq-type equations (NHM-BTE) is critically examined through several free-surface wave examples. Overall model results show that NHM-BTE using only a few vertical layers (i.e., two ∼ four) is capable of accurately simulating highly dispersive wave motion and wave transformation over irregular bathymetry.
APA, Harvard, Vancouver, ISO, and other styles
6

Martinez, R., J. S. Uhlman, C. M. Ting, B. S. Paul, J. M. Anderson, M. C. Goody, and D. O. Stewart. "Understanding Roughness Noise: Progress in Analytical Modeling and Testing, Part 1—Shear Rapid Distortion Theory." In ASME 2008 Noise Control and Acoustics Division Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ncad2008-73036.

Full text
Abstract:
This is the first of a two-part paper that lays out a theory of broadband noise from rough surfaces and uses it to interpret recent experimental data. The analysis in Part 1 is based on an application of Rapid Distortion Theory to an incident field of correlated micro-velocities defined upstream of the roughened region. Those velocity disturbances are linked to the frequency-wavenumber spectrum of wall pressures from a standard model of turbulent boundary-layer flow. The field of incident microvelocities distorts as it is convected irregularly around and over the roughness elements and thereby generates the predicted broadband sound. Computed results in the Part-2 paper will gauge the role of a boundary layer’s mean shear in the noise-production process relative to the rapid distortions carried by an artificially irrotational mean flow (for reasons to be described in Part 2, shear effects turn out to be insignificant for the application of immediate interest). Calculations in support of recent measurements will be presented for a range of operating conditions and for their associated set of dimensionless scaling parameters.
APA, Harvard, Vancouver, ISO, and other styles
7

Kolaei, Amir, Subhash Rakheja, and Marc J. Richard. "Anti-Sloshing Effects of Longitudinal Partial Baffles in a Partly-Filled Container Under Lateral Excitation." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-37271.

Full text
Abstract:
This study is aimed at analysis of transient lateral slosh in a partially-filled cylindrical tank with different designs of longitudinal partial baffles using a coupled multimodal and boundary-element method. A boundary element method is initially formulated to solve the eigenvalue problem of free liquid slosh, assuming inviscid, incompressible and irrotational flows. Significant improvement in computational time is achieved by reducing the generalized eigenvalue problem to a standard one involving only the velocity potentials on the half free-surface length using the zoning method. The generalized coordinates of the free-surface oscillations under a lateral excitation are then obtained from superposition of the natural slosh modes. The lateral slosh force is also formulated in terms of the generalized coordinates and hydrodynamic coefficients. The validity of the model is illustrated through comparisons with available analytical solutions. Two different designs of longitudinal baffles are considered: bottom- and top-mounted baffles. The effect of different baffle designs on the normalized slosh frequencies, modes and lateral force are investigated. It is shown that the multimodal method yields computationally efficient solutions of liquid slosh within moving baffled containers. The results suggest that the effectiveness of baffles in suppressing the liquid oscillations is strongly affected by the baffle length relative to the free-surface height. The top-mounted baffle yields the greatest effectiveness, when it pierces the free-surface. The bottom-mounted baffle, however, may not be considered as an efficient mean for controlling the liquid slosh in tank vehicles where the liquid fill height is above 50%.
APA, Harvard, Vancouver, ISO, and other styles
8

Zhou, W., and G. (Terry) Huang. "Model Error Assessment of Burst Capacity Models for Defect-Free Pipes." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90334.

Full text
Abstract:
The model errors associated with 19 burst pressure prediction models for defect-free thin-walled pipes are evaluated using a total of 76 full-scale burst test data of perfect pipes and pressure vessels collected from the literature. The considered models are based on the Tresca yield criterion, the von Mises yield criterion, or the average shear stress yield criterion. The probabilistic characteristics of the model error, i.e. the mean, coefficient of variation and best-fit probability distribution, are obtained based on the test-to-predicted ratios. The applicability of an empirical equation for estimating the strain hardening exponent in the burst capacity models is also evaluated. The model errors obtained in this study can be used in the structural reliability analysis of energy pipelines with respect to the limit state of burst of defect-free pipes and will facilitate the reliability-based design and assessment of pipelines.
APA, Harvard, Vancouver, ISO, and other styles
9

Matsui, Tetsuya. "Sloshing in a Cylindrical Liquid Storage Tank With a Single-Deck Type Floating Roof Under Seismic Excitation." In ASME 2007 Pressure Vessels and Piping Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/pvp2007-26249.

Full text
Abstract:
An explicit analytical solution is derived to predict the sloshing response of a cylindrical liquid storage tank with a single-deck type floating roof under seismic excitation. The floating roof is composed of an inner deck which may be idealized as an isotropic elastic plate with uniform thickness and connected to an outer pontoon which can be considered as an elastic curved beam. The contained liquid is assumed to be inviscid, incompressible and irrotational. By expanding the response of the floating roof into free vibration modes in air and applying the Fourier-Bessel expansion technique in cylindrical coordinates, the solution is obtained in an explicit form which is exact within the framework of linear potential theory. Numerical results are presented to investigate the effect of the type (single-deck or double-deck) and stiffness of the floating roof on the sloshing response.
APA, Harvard, Vancouver, ISO, and other styles
10

Matsui, Tetsuya. "Sloshing in a Cylindrical Liquid Storage Tank With a Floating Roof Under Seismic Excitation." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93531.

Full text
Abstract:
An analytical solution is presented to predict the sloshing response of a cylindrical liquid storage tank with a floating roof under seismic excitation. The contained liquid is assumed to be inviscid, incompressible and irrotational, while the floating roof is idealized as an isotropic elastic plate with uniform stiffness and mass. The dynamic interaction between the floating roof and the liquid is taken into account exactly within the framework of linear potential theory. By expanding the response of the floating roof into free vibration modes in air and employing the Fourier-Bessel expansion method in cylindrical coordinates, the solution is obtained in an explicit form which is useful for parametric understanding of the sloshing behavior and preliminary study in the early design stage. Numerical results are also provided to investigate the effect of the stiffness and mass of the floating roof on the sloshing response.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Shear-free and irrotational models' for particular source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography