CARPET 1:
Experimental characterization of disperse, multiphase flows

Objectives:

To perform experiments on local distributions of important fluid flow variables, particle size and shape distributions, interfacial area, and momentum transfer.

Focus will be on selected physical phenomena. Simple experimental apparatus providing well defined flow conditions (e.g. instantaneous velocities, turbulence intensity, turbulent length scales, etc.) will be constructed to obtain general information on the fluid/particle interaction phenomena. Dispersed systems ranging from very dilute to dense will be analyzed. Both fine and coarser particles can be applied in mono- and poly- dispersed suspensions. Furthermore, underlying models intending to describe near wall phenomena (e.g. wall laws) should be validated for dispersed flows.

The background flow field will be characterized by LDV, while the particle movement will be measured using PIV and Optical Probes.

The work is intended to result in better understanding and predictions of movement and deformation of fluid particles, both for dilute and dense systems, and for wall boundary layers considering bubbly flows.

Background:

The existing CFD based reactor models are still on an early stage and further development is needed. The present multiphase flow codes contain many uncertain closure schemes, constitutive laws and model con-cepts.

To develop an accurate and properly closed model, which can be used for the mechanistic predictions of time dependent 3D flows, we need to improve our fundamental understanding of the flow phenomena and interfacial mechanisms occurring in industrial reactors.

It is obvious that reliable models can only be developed in the combination with laboratory work obtaining high quality experimental data for validation.

Scope of work:

The doctor study will focus on experimental techniques, measurements and model validation.

Affiliation:

NTNU, Department of Chemical Engineering.

Supervisors:

Hallvard F. Svendsen in collaboration with Tor Ytrehus, Hugo A. Jakobsen, Paal Skjetne , and Harald Laux.