this paper is concerned with asphaltene deposition in fluid flowing through pipelines. brownian diffusion and drag, gravitational, thermophoresis, buoyancy, and shear removal are considered as possible mechanisms in the asphaltene deposition process. the thermo-physical properties of the fluid were obtained from iranian oil fields. a model was used in the pipeline deposition modeling to predict...

In a fluid-saturated porous medium, dissolved species advect at the pore velocity, while thermal retardation causes heat to move at the Darcy velocity. The Darcy model with the Boussinesq approximation in a square medium with a porosity of φ= 0.01 subject to two sources of buoyancy is used, to study numerically the dynamics of this so-called double-advective instability. The vertical walls of t...

A two-week dataset from a partially and periodically stratified estuary quantifies variability in the turbulence across the tidal and spring–neap time scales. These observations have been fit with a twoparameter model of the Reynolds stress profile, which produces estimates of the time variation of the bottom boundary layer height and the friction velocity. Conditions at the top of the bottom b...

The field effects of buoyancy on laminar and turbulent premixed v-flames have been studied by the use of laser Doppler velocimetry to measure the velocity statistics in +1g, -1g and μg flames. The experimental conditions covered mean velocity, Uo, of 0.4 to 2 m/s, methane/air equivalence ratio, φ, of 0.62 to 0.75. The Reynolds numbers, from 625 to 3130 and the Richardson number from 0.05 to 1.3...

Convection in a cylindrical container of small aspect ratio is studied. It is known that when, in addition to buoyancy forces, thermocapillarity effects are taken into account, resonant interactions of two modes may appear. In the case of 1:2 resonance amplitude equations are derived, showing the existence of a stable heteroclinic orbit and rotating waves, until now not observed experimentally.