Search results for "Knudsen number"

showing 3 items of 13 documents

Effects of partial thermalization on HBT interferometry

2009

Hydrodynamical models have generally failed to describe interferometry radii measured at RHIC. In order to investigate this ``HBT puzzle'', we carry out a systematic study of HBT radii in ultrarelativistic heavy-ion collisions within a two-dimensional transport model. We compute the transverse radii $R_o$ and $R_s$ as functions of $p_t$ for various values of the Knudsen number, which measures the degree of thermalization in the system. For realistic values of the Knudsen number estimated from $v_2$ data, we obtain $R_o/R_s \simeq 1.2$, much closer to data than standard hydrodynamical results. Femtoscopic observables vary little with the degree of thermalization. Azimuthal oscillations of th…

PhysicsNuclear and High Energy PhysicsNuclear TheoryHeterojunction bipolar transistorFOS: Physical sciencesObservableNuclear Theory (nucl-th)Nuclear physicsAzimuthTransverse planeInterferometryThermalisationKnudsen numberNuclear ExperimentNuclear theoryNuclear Physics A
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Relative importance of second-order terms in relativistic dissipative fluid dynamics

2013

In Denicol et al., Phys. Rev. D 85, 114047 (2012), the equations of motion of relativistic dissipative fluid dynamics were derived from the relativistic Boltzmann equation. These equations contain a multitude of terms of second order in Knudsen number, in inverse Reynolds number, or their product. Terms of second order in Knudsen number give rise to non-hyperbolic (and thus acausal) behavior and must be neglected in (numerical) solutions of relativistic dissipative fluid dynamics. The coefficients of the terms which are of the order of the product of Knudsen and inverse Reynolds numbers have been explicitly computed in the above reference, in the limit of a massless Boltzmann gas. Terms of …

PhysicsNuclear and High Energy PhysicsNuclear Theoryta114Lattice Boltzmann methodsFluid Dynamics (physics.flu-dyn)Reynolds numberFOS: Physical sciencesPhysics - Fluid DynamicsNonlinear Sciences::Cellular Automata and Lattice GasesBoltzmann equationPhysics::Fluid DynamicsNuclear Theory (nucl-th)High Energy Physics - Phenomenologysymbols.namesakeClassical mechanicsHigh Energy Physics - Phenomenology (hep-ph)Boltzmann constantsymbolsDissipative systemFluid dynamicsKnudsen numberDirect simulation Monte CarloPhysical Review D
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Extended Environmental Contour Methods for Long-Term Extreme Response Analysis of Offshore Wind Turbines1

2020

Abstract Environmental contour method is an efficient method for predicting the long-term extreme response of offshore structures. The traditional environmental contour is obtained using the joint distribution of mean wind speed, significant wave height, and spectral peak period. To improve the accuracy of traditional environmental contour method, a modified method was proposed considering the non-monotonic aerodynamic behavior of offshore wind turbines. Still, the modified method assumes constant wind turbulence intensity. In this paper, we extend the existing environmental contour methods by considering the wind turbulence intensity as a stochastic variable. The 50-year extreme responses …

Turbulence020209 energyMechanical EngineeringOcean Engineering02 engineering and technologySpace (mathematics)Wind speedTerm (time)Extreme ResponseOffshore wind power020401 chemical engineering0202 electrical engineering electronic engineering information engineeringEnvironmental scienceKnudsen number0204 chemical engineeringMarine engineeringJournal of Offshore Mechanics and Arctic Engineering
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