A gas bubble rising steadily in a pure liquid otherwise at rest at a moderate Weber number is, to a good approximation, of oblate spheroidal shape. Previous analytical calculations of that shape at high Reynolds numbers have ignored viscosity. This paper shows that if one includes viscosity by incorporating Rayleigh’s dissipation integral in Lagrange’s equations, then the speed of rise is that ...

a r t i c l e i n f o a b s t r a c t Keywords: viscosity lower mantle mantle plume elasticity spin transition A proper determination of the lower-mantle viscosity profile is fundamental to understanding Earth geodynamics. Based on results coming from different sources, several models have been proposed to constrain the variations of viscosity as a function of pressure, stress and temperature. ...

We present analytical solutions of the hydrodynamic resistance force a spherical particle experiences when it moves through a polymer solution containing nonadsorbing chains. Polymer depletion results in a reduced polymer concentration and fluid viscosity near the particle surface. The nonuniform physical properties in the fluid phase affect the transport behavior of a translating and rotating ...

The use of ®rst-principles molecular dynamics to calculate the viscosity of liquid metals using the Green±Kubo relations is described. The ®rst-principles techniques are based on density functional theory, the pseudopotential approximation, and plane-wave basis sets. The statistical-mechanical basis of the Green±Kubo relations is summarised, and extensive ®rst-principles molecular dynamics simu...

Presented are quantum simulation results using a measurement-based quantum lattice gas algorithm for Navier-Stokes fluid dynamics in 2+1 dimensions. Numerical prediction of the kinematic viscosity was measured by the decay rate of an initial sinusoidal flow profile. Due to local quantum entanglement in the quantum lattice gas, the minimum kinematic viscosity in the measurement-based quantum lat...

The capabilities and limitations of various molecular viscosity models, when testing Left Coronary Artery (LCA) tree, were analyzed via: molecular viscosity, local and global non-Newtonian importance factors, Wall Shear Stress (WSS) and Wall Shear Stress Gradient (WSSG). Seven non-Newtonian molecular viscosity models, plus the Newtonian one, were compared. Dense grid of 620000 nodes located, mo...

−− The falling cylinder viscometer (FCV) is a reliable instrument to quantify the viscosity of Newtonian fluids. Nevertheless, when nonNewtonian fluids are tested in this device, difficulties appear to determine the apparent viscosity. Thus, conventional rheometric calculations cannot be applied directly to experimental data provided by the FCV in order to obtain the apparent viscosity function...

We present Helmholtz or Helmholtz like equations for the approximation of the timeharmonic wave propagation in gases with small viscosity, which are completed with local boundary conditions on rigid walls. We derived approximative models based on the method of multiple scales for the pressure and the velocity separately, both up to order 2. Approximations to the pressure are described by the He...

Our goal is to develop robust numerical methods for solving mathematical models of nonlinear phenomena such as nonlinearconservation laws, advection-dominated multi-phase flows, and free-boundary problems, where shocks, fronts, and contactdiscontinuities are driving features and pose significant difficulties for traditional numerical methods. We have discovered thattime-dependen...