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Showing 1 to 13 of 13 for “"shear-free"”.
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Shear-free perfect fluid theorems in general relativity
We present a detailed method for proving shear-free perfect fluid theorems in General Relativity. This method uses the (1+3)-covariant formalism to establish the consistency of the Einstein gravitational field equations under the barotropic shear-free perfect fluid condition. Using a Mathematica …
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Large Eddy Simulation of Shear-Free Interaction of Homogeneous Turbulence with a Flat-Plate Cascade
Studying the effects of free stream turbulence on noise, vibration, and heat transfer on structures is very important in engineering applications. The problem of the interaction of large scale turbulence with a flat-plate cascade is a model of important problems in propulsion systems. Addressing …
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Contributions to the study of shear-free and of purely radiative perfect fluids in general relativity
A study of shear-free perfect fluids in general relativity (rotating and/or expanding) and a characterisation of the orthogonal Bianchi class A perfect fluids as geodesic, non-rotating fluids with vanishing divergence of the electric and magnetic part of the Weyl tensor.
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Analysis of Viscous Drag Reduction and Thermal Transport Effects for Microengineered Ultrahydrophobic Surfaces
… flow at the liquid-vapor interface is treated as shear-free (vanishing viscosity in the vapor region), and 2) the liquid flow in the microchannel core and the vapor flow within the cavity are coupled through the velocity and shear stress matching at the interface. Predictions reveal that …
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Differential systems, moving frames, structure-preserving submersions and geometrical problems in physics
… method, we can rapidly determine the number of free functions that we must specify in order to completely specify the problem, which we will call the “degree of arbitrariness” of the problem, and which for many physical systems is linked to the physical degree of freedom. This algorithm is …
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Experimental Study of Wall Shear Stress Modification by Surface Coating: Pressure Drop Measurements in a Rectangular Channel
… equation, and do not show any reduction in wall shear stress as a function of material properties or surface chemistry. The differences between this experiment and others measuring pressure drop over hydrophobic surfaces is the macro-scale conditions and the hydrophobic surfaces being fully …
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Enhancing Injectability and Viability of Cells using Viscoplastic Lubricated Flows
… substantial forces which also lead to high shear in the cell and ultimately cell death. Current methods to mitigate this problem suffer from limited applicability, poor durability, lack of stability and no significant enhancement in injectability. Here, we propose a viscoplastic lubricated …
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Dynamical studies in relativistic cosmology
… the electric part or the magnetic part of the free gravitational field are not rotationally symmetric, and also make a brief comment on the most general case where only the shear is rotationally symmetric. We use a tetrad analysis to show that the well-known result that holds for relativistic …
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Several applications of a model for dense granular flows
… to perform well when modelling certain simple free surface flows. We extend the application of this model to a wide range of flow configurations, beginning with six simple flows studied in detailed experiments (GDR MiDi, 2004, Eur. Phys. J. E, 14, 341-366). Two-dimensional shearing flows and …
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Linking Rheological and Processing Behavior to Molecular Structure in Sparsely-Branched Polyethylenes Using Constitutive Relationships
… known as encapsulation in order to carry out shear-free rheological characterization. Ductile failure prevents the rheological measurement of transient stress growth at higher strains for certain strain-hardening materials. This reduces the accuracy of nonlinear parameters for constitutive …
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Conformal symmetries in special and general relativity.The derivation and interpretation of conformal symmetries and asymptotic conformal symmetries in Minkowski space-time and in some space-times of general relativity.
… spacetimes which admit an asymptotically shear-free congruence of null geodesics, and in Chapter 6 the conformal rescaling technique of Penrose [54] is used both to support the findings of the previous chapter and to set out a procedure for solution in the general case. It is pointed out …
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Topics in relativistic cosmology: Cosmology on the past lightcone and in modified gravitation
… consistency of the linearised dust models for shear-free cases as well as in the limiting cases when either the gravito-magnetic or gravito-electric components of the Weyl tensor vanish. We also discuss the existence and consistency of classes of non-expanding irrotational spacetimes in …
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The Role of Branching Topology on Rheological Properties and its Effect on Film-Casting Performance
… The work includes analysis of the rheology in shear and shear-free flows for sparsely long-chain branched, LCB, polyethylene, PE, resins; determination of the consistency of the molecular based constitutive model, the pom-pom model; for these flows, and evaluation of the same PE resins in …