We present an entirely analytic, leading log order determination of the friction an electroweak bubble wall feels during a first order electroweak phase transition. The friction is dominated by W bosons, and gives a wall velocity parametrically ∼ αw, and numerically small, ∼ .01 −− 0.1 depending on the Higgs mass.

Flat plate skin friction calculations over a range of Mach numbers from 0.4 to 3.5 at Reynolds numbers from 16 million to 492 million using a Navier Stokes method with advanced turbulence modeling are compared with incompressible skin friction coefficient correlations. The semi-empirical correlation theories of van Driest; Cope; Winkler and Cha; and Sommer and Short T’ are used to transform the...

When using shear testing to determine wall friction of pharmaceutical particulate systems, it is crucial to measure at the correct wall normal stress. By comparing data obtained at a wall normal stress of 1000 to 200 Pa, the effect of the applied stress on the accuracy and precision of the method was assessed. INTRODUCTION When powder flows under gravity from a hopper, it follows one of two pat...

This paper is concerned with the evaluation of wall or boundary friction, adhesion and wear in bins and chutes of bulk solid handling plant. The relevant parameters influencing wall friction, such as surface roughness and particle size, are described and the manner in which friction, adhesion and cohesion influence performance of bins and chutes is discussed. Particular attention is focussed on...

The observed flow enhancement in highly confining geometries is believed to be caused by fluid velocity slip at the solid wall surface. Here we present a simple and highly accurate method to predict this slip using equilibrium molecular dynamics. Unlike previous equilibrium molecular dynamics methods, it allows us to directly compute the intrinsic wall-fluid friction coefficient rather than an ...

Large-eddy simulations (LES) of turbulent flow in a smoothwall pipe at Reynolds numbers based on the pipe Radius R and wall friction velocity in the range Reτ = 2,000−2,000,000 are discussed. Using a Reynolds number based on D and the bulkflow velocity, then corresponding values are ReD = 91,800 − 165,000,000. For the LES, the spectral-element code SEMTEX was used combined with the stretched-vo...

We consider the dynamics of bubble growth in the Minimal Standard Model at the electroweak phase transition and determine the shape and the velocity of the phase boundary, or bubble wall. We show that in the semi-classical approximation the friction on the wall arises from the deviation of massive particle populations from thermal equilibrium. We treat these with Boltzmann equations in a fluid ...

We study experimentally the flow of a foam confined as a bubble monolayer between two plates through a convergent channel. We quantify the velocity, the distribution and orientation of plastic events, and the elastic stress, using image analysis. We use two different soap solutions: a sodium dodecyl sulfate (SDS) solution, with a negligible wall friction between the bubbles and the confining pl...

In this paper the influence of the moisture content on the flow characteristics of blast furnace dust is investigated. The flowability of granular material is essential for the design and operation of dust separators, transport equipment and storage silos. Two blast furnace dust samples from different blast furnaces were investigated. The moisture content was adapted for measurement with the sh...

An effort is made to evaluate the formulation of seismic active earth pressure behind a nonvertical retaining wall supporting c-Ф backfill. The formulation is prepared to get a single critical wedge surface for simultaneous action of weight, surcharge, cohesion and adhesion. The success of any retaining structure involves the awareness of seismic active earth pressure. The effect of various par...