We use a three dimensional hydrodynamical code to simulate the effect of energy injection on cooling flows in the intracluster medium. Specifically, we compare a simulation of a 10 M cluster with radiative cooling only, with a second simulation in which thermal energy is injected 31 kpc off-centre, over 64 kpc at a rate of 4.9×1044ergs s−1 for 50 Myr. The heat injection forms a hot, low density...

Why did the mortgage market melt down so badly? Why were there so many defaults when the economy was not particularly weak? Why were the securities based upon these mortgages not considered anywhere as risky as they actually turned out to be? It is the thesis of this paper that, in an attempt to increase homeownership, particularly by minorities and the less affluent, an attack on underwriting ...

Two new Gauge–Uzawa schemes are constructed for incompressible flows with variable density. One is in the conserved form while the other is in the convective form. It is shown that the first-order versions of both schemes, in their semi-discretized form, are unconditionally stable. Numerical experiments indicate that the first-order (resp. second-order) versions of the two schemes lead to first...

A new framework for two-fluids flow using a Finite Element/Level Set method is presented and verified through the simulation of the rising of a bubble in a viscous fluid. This model is then enriched to deal with vesicles (which mimic red blood cells mechanical behavior) by introducing a Lagrange multiplier to constrain the inextensibility of the membrane. Moreover, high order polynomial approxi...

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 ...

We discuss the rise of a liquid inside an angular capillary tube. It is shown that for a wetting liquid, the height of the rise is (as usually) inversely proportional to the length which characterizes the confinement. The exact laws deduced from energetic considerations are found to be in excellent agreement with the data. We then show how such tubes can be used to prevent bubbles from being tr...

In this note we discuss the combination of the classical CSS and CSF approaches with special FEM techniques towards a fully implicit distance-free level set method. Based on a new surface stress formulation, neither normals nor curvature have to be explicitly calculated, and also the explicit redistancing can be avoided so that a monolithic formulation of the corresponding multiphase problem ge...

This paper disentangles direct spillovers and common factors as sources of correlations in simultaneous heteroscedastic systems. While these different components are not identifiable by standard means without restrictions, it is shown that they can be pinned down by specifying the variances of the latent idiosyncratic and common shocks as ARCH-type processes. Applying an adapted Kalman filter e...

The mass transfer between immiscible two-liquid phases can be greatly enhanced by bubbling gas through a reactor. Numerous micro water droplets breaking out from a ruptured water film around a rising bubble through the oil (upper phase)/water (lower phase) interface were demonstrated in the preceding paper (Uemura T., Ueda Y. and Iguchi M., Europhys. Lett., 92 (2010) 34004). In this letter, we ...

Bubble lift-off diameter is characterized as the size of a bubble rising from wall, which vital in boundary condition heat transfer model and interfacial area transport equation. In this paper, mechanistic force analysis was conducted to explore predictive for vertical channel subcooled boiling flow. Specifically, component growth normal wall shear lift lead on surface. Through analysis, we fou...