Kinematic and Dynamic Parameters of a Liquid-Solid Pipe Flow Using DPIV∕Accelerometry

Abstract

An experimental investigation of a two-phase pipe flow was undertaken to study kinematic and dynamic parameters of the fluid and solid phases. To accomplish this, a two-color digital particle image velocimetry and accelerometry (DPIV∕DPIA) methodology was used to measure velocity and acceleration fields of the fluid phase and solid phase simultaneously. The simultaneous, two-color DPIV∕DPIA measurements provided information on the changing characteristics of two-phase flow kinematic and dynamic quantities. Analysis of kinematic terms indicated that turbulence was suppressed due to the presence of the solid phase. Dynamic considerations focused on the second and third central moments of temporal acceleration for both phases. For the condition studied, the distribution across the tube of the second central moment of acceleration indicated a higher value for the solid phase than the fluid phase; both phases had increased values near the wall. The third central moment statistic of acceleration showed a variation between the two phases with the fluid phase having an oscillatory-type profile across the tube and the solid phase having a fairly flat profile. The differences in second and third central moment profiles between the two phases are attributed to the inertia of each particle type and its response to turbulence structures. Analysis of acceleration statistics provides another approach to characterize flow fields and gives some insight into the flow structures, even for steady flows.

Turbulent stresses and particle break-up criteria in particle-laden pipe flows

“…Similar modifications to the mean axial fluid velocity of particle-laden case 1B are found for upward cases 1A/1C. The minor effect of solid particles on the mean liquid velocity was also shown by Sato and Hishida (1996) and by Borowsky and Wei (2007) in wall-bounded flows, particularly if low mean volumetric loads of solids are present (e.g. less than 10 À4 ).…”

Numerical study of particle turbulence interaction in liquid‐particle flows

“…The majority of the trend shows a decrease in particulate turbulent kinetic energies, after which they more or less remain a constant. Previous studies of liquid‐particle flows in vertical channel9, 10 shows that with the increase in the Stokes number there is usually a corresponding increase in the particulate turbulence, however the flow considered in this study is a shear flow geometry, which basically depicts a totally different flow feature unlike the simple channel geometry. In these lines even the turbulence modification (TM) of the shear flow geometry for the well established gas‐particle flow11 does not seem to well correspond with the models been employed and formulated for the vertical channel flows 2.…”

Numerical Study of Particle Interaction in Gas-Particle and Liquid-Particle Flows: Part I Analysis and Validation

“…A nearly homogenous flow like liquid-particle flow can circumvent this problem, wherein all turbulence properties are attributed due to the relative motion of the particles; thereby any change felt due to the dispersed phase on the carrier phase is a direct result of only the TM phenomenon (Parthasarthy and Faeth;. This phenomenon have been exploited by many experimental researchers 1987, Parthasarthy and Faeth;1990, Alajbejovic et al;1994, Rashidi et al;1990, Sato & Hishida;1996, Ishima et al;2007, Borowsky & Wei;2007, Righetti & Romano; to not only investigate, study and understand the basic features of TM but also to aid in the better formulation of numerical models. A number of previous studies have examined particle response for gas-particle flows in a sudden expansion flow experimentally (Ruck & Makiola;1988, Hishida & Maeda;, Fessler & Eaton, 1997.…”